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The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Increasing nutrient supply to dairy calves has well known benefits; however, the effects of milk replacer (MR) composition when supplied in higher amounts are not fully understood, particularly in the first weeks of life. To better understand the metabolism of macronutrient supply in young calves (21 d old), we investigated diurnal patterns of heat production and substrate oxidation in young calves fed MR with an incremental supply of fat, lactose, or protein. Thirty-two groups of 3 mixed-sex Holstein-Friesian newborn calves (3.4 ± 1.6 d of age), were randomly assigned to one of 4 dietary treatments and studied for 21 d. Diets consisted of a basal MR (23.3% CP, 21.2% EE, and 48.8% lactose of DM) fed at 550 kJ/kg BW0.85 per day (CON; n = 24), or the basal MR incrementally supplied with 126 kJ of digestible energy/BW0.85 per day as milk fat (+FAT; n = 23), lactose (+LAC; n = 24), or milk protein (+PRO; n = 23). Calves were fed MR in 2 daily meals and had ad libitum access to water, but were not supplied with any calf starter nor forage. After 2 weeks of adaptation to the diets, groups of 3 calves were placed for 1 wk in an open-circuit respiration chamber for nitrogen and energy balance measurements (lasting 7 d). On d 3, glucose oxidation kinetics was estimated by using [U-13C]glucose. Measurements included total heat production (total energy [HP], activity [H act ] expenditure, resting metabolic rate [RMR]), respiration quotient (RQ), carbohydrate (COX) and fat oxidation (FOX) in 10 min. intervals and averaging these values per hour over days. Incremental supply of lactose and fat increased body fat deposition, with observed patterns in RMR indicating that this increase occurred primarily after the meals. Specifically, the average daily RMR was highest in the +PRO group and lowest in the CON treatment. The HP was higher in the +PRO group and throughout the day, hourly means of HP were higher in this treatment mainly caused by an increase in H act. The recovery of 13CO 2 from oral pulse-dosed [U-13C]glucose was high (77%), and not significantly different between treatments, indicating that ingested lactose was oxidized to a similar extent across treatments. Increasing lactose supply in young calves increased fat retention by reduction in fatty oxidation. Calves fed a MR with additional protein or fat raised RMR persistently throughout the day, whereas the extra lactose supply only affects RMR after the meal. Dietary glucose was almost completely oxidized (77% based on (13C) glucose measurement) regardless of nutrient supplementation. Extra protein supply increased HP and FOX compared with similar intakes of fat and lactose. Fasting heat production (FHP) of young, group-housed calves is comparable to literature values and unaffected by energy intake. Overall, these findings deepen our understanding of how different nutrients affect metabolic processes, fat retention, and energy expenditure in young dairy calves. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Streptococcus thermophilus is a common starter in yogurt production and plays an important role in the dairy industry. In this study, a galactose-positive (Gal+) mutant strain, IMAU20246Y, was produced using the chemical mutagen N-methyl-N′-nitro-N-nitrosoguanidine (NTG) from wild-type S. thermophilus IMAU20246, which is known to have good fermentation characteristics. The sugar content of milk fermented by either the mutant or the wild type was determined using HPLC; metabolism of lactose and galactose was significantly increased in the mutant strain. In addition, we used response surface methodology to optimize components of the basic M17 medium for survival ratio of the mutant strain. Under these optimal conditions, the viable counts of mutant S. thermophilus IMAU20246Y reached 4.15 × 108 cfu/mL and, following freeze-drying in the medium, retained cell viability of up to 67.42%. These results are conducive to production of a high-vitality starter culture and development of "low sugar, high sweetness" dairy products. [ABSTRACT FROM AUTHOR]

Several studies have described variations in lactose content (LC) in dairy cows during udder quarter health disorder or negative energy balance (NEB). However, their joint effects on LC have never been described. This was the aim of a longitudinal observational study performed on 5 Quebec dairy farms using automatic milking systems. Quarter milk samples were collected every 14 d from 5 to 300 DIM. Quarter health status was described by combining SCC level (SCC− or SCC+: < or ≥100,000 cells/mL, respectively) and infectious status (Patho− or Patho+: absence or presence of pathogens on a milk culture, respectively). Cows with NEB in early lactation (DIM <70) were identified using milk BHB content: <0.15 m M = BHB−; 0.15 to 0.19 m M = BHB+; >0.19 m M = BHB++. A total of 14,505 quarter cisternal milk samples were collected from 380 lactating cows. The quarter LC was analyzed using a mixed linear regression model with the following fixed effects: quarter health status, parity, time interval between last milking and sampling, quarter milk yield (in kg/d), DIM, and herd. A random quarter intercept with a repeated measures correlation structure and a cow random intercept were also specified. The LC of SCC+ quarters was lower (−0.17 ± 0.013 percentage points) compared with LC of SCC- quarters for both primiparous and multiparous cows. Of the 162 bacterial species identified, only 8 species had a prevalence greater than 4.0%, and just 5 of them were associated with a reduction in LC: Staphylococcus aureus , Staphylococcus chromogenes , Streptococcus dysgalactiae , Staphylococcus epidermidis , and Staphylococcus simulans. Cows identified as BHB+ and BHB++ in early lactation had a lower LC (−0.05 ± 0.019 and −0.13 ± 0.020 percentage points, respectively) compared with BHB− cows. For BHB++ cows, in both parity groups the decrease in LC (−0.20 ± 0.025 percentage points) was higher in SCC+ quarters compared with SCC− quarters. Moreover, the additive effect of the quarter health status and NEB on milk LC was greater with larger increases in BHB. Our findings highlight the necessity to jointly take into consideration both quarter health status and milk BHB concentration when using LC as a biomarker for NEB. [ABSTRACT FROM AUTHOR]

Net energy for lactation (NE L) and metabolizable protein (MP) are the 2 main nutritional forces that drive synthesis of milk components. This study investigated mammary-gland metabolism in dairy cows in response to variations in the supply of NE L and MP. Four Holstein dairy cows were randomly assigned to a 4 × 4 Latin square design, in which each experimental period consisted of 14 d of dietary treatment. The diets provided 2 levels of NE L (low energy, 25.0 Mcal/d vs. high energy, 32.5 Mcal/d) and 2 levels of MP (low protein, 1,266 g/d vs. high protein, 2,254 g/d of protein digestible in the intestine) in a 2 × 2 factorial arrangement. Performance and dry matter intake (DMI) were measured during the last 5 d of each period, and the mammary net balance was measured on d 13 by collecting 6 sets of blood samples from the left carotid artery and left mammary vein. Mammary plasma flow was measured according to the Fick principle for Phe and Tyr. The mammary net balance of carbon equaled the uptake of nutrients expressed as carbon minus the output of lactose, fatty acids (FA) synthesized in the mammary gland, AA of milk protein, and glycerol-3P from triglyceride on d 13. Milk, lactose, fat, and protein yields increased when NE L and MP supplies increased. However, increasing the NE L supply increased FA synthesis more than increasing the protein supply did. In addition, FA secretion increased more than lactose secretion when the NE L supply increased. Increasing the NE L supply increased the left half-udder uptake of all major energy-yielding nutrients by increasing mammary plasma flow. However, nutrient uptake increased more than milk output did, which in turn increased carbon dioxide output. This increase in nutrient oxidation by the mammary gland decreased the mammary efficiency of nutrients utilization when the NE L supply increased. Increasing MP supply tended to increase glucose uptake through mammary clearance and increased mammary AA uptake with no change in mammary plasma flow. In addition, the protein supply did not change the mammary uptake of acetate or β-hydroxybutyrate. The increase in milk-component secretions in response to either NE L or MP supplies occurred through different metabolic adaptations (increase in mammary plasma flow vs. clearances, respectively). These results suggest that the nutrient use by the mammary gland is highly flexible, which helps in maintaining milk and milk-component yields even with limiting nutrient supplies. [ABSTRACT FROM AUTHOR]

Anti-inflammatory activities of catechin-rich green tea extract (GTE) in obese rodents protect against metabolic endotoxemia by decreasing intestinal permeability and absorption of gut-derived endotoxin. However, translation to human health has not been established. We hypothesized that GTE would reduce endotoxemia by decreasing gut permeability and intestinal and systemic inflammation in persons with metabolic syndrome (MetS) compared with healthy persons. A randomized, double-blind, placebo-controlled, crossover trial in healthy adults (n = 19, 34 ± 2 years) and adults with MetS (n = 21, 40 ± 3 years) examined 4-week administration of a decaffeinated GTE confection (890 mg/d total catechins) on serum endotoxin, intestinal permeability, gut and systemic inflammation, and cardiometabolic parameters. Compared with the placebo, the GTE confection decreased serum endotoxin (P =.023) in both healthy persons and those with MetS, while increasing concentrations of circulating catechins (P <.0001) and γ-valerolactones (P =.0001). Fecal calprotectin (P =.029) and myeloperoxidase (P =.048) concentrations were decreased by GTE regardless of health status. Following the ingestion of gut permeability probes, urinary lactose/mannitol (P =.043) but not sucralose/erythritol (P >.05) was decreased by GTE regardless of health status. No between-treatment differences (P >.05) were observed for plasma aminotransferases, blood pressure, plasma lipids, or body mass nor were plasma tumor necrosis factor-α, interleukin-6, or the ratio of lipopolysaccharide-binding protein/soluble cluster of differentiation-14 affected. However, fasting glucose in both study groups was decreased (P =.029) by the GTE confection compared with within-treatment arm baseline concentrations. These findings demonstrate that catechin-rich GTE is effective to decrease circulating endotoxin and improve glycemic control in healthy adults and those with MetS, likely by reducing gut inflammation and small intestinal permeability but without affecting systemic inflammation. • A novel green tea extract (GTE) confection was provided to healthy adults and adults with metabolic syndrome. • GTE increased circulating catechins and valerolactones regardless of health status. • GTE decreased intestinal inflammation and small intestinal permeability. • GTE decreased circulating endotoxin. • GTE decreased fasting glucose without affecting systemic inflammation. • Gut-level benefits by GTE support research translation for cardioprotection by green tea. Healthy adults and adults with metabolic syndrome were randomized to a placebo or GTE (1 g; 890 mg catechins) confection for 1 month and then crossed-over to the alternative treatment following a 1-month washout. Regardless of health status, the GTE confection decreased fecal biomarkers of intestinal inflammation (calprotectin and myeloperoxidase) and small intestinal permeability based on a differential sugar absorption test while decreasing serum endotoxin. Abbreviations: GTE, green tea extract; MetS, metabolic syndrome [Display omitted] [ABSTRACT FROM AUTHOR]

Lactulose was produced from lactose using subcritical phosphate or carbonate buffer solution. Phosphate buffer with an initial pH of 8.0 accomplished the maximum yield of 29% at 120 °C. A long reaction time and high pH led to the rapid decomposition of lactulose and a large color change of the reaction solution. The formation of some monosaccharides, such as glucose, galactose, fructose, tagatose, talose, allulose, and sorbose, occurred due to the hydrolysis and isomerization reactions in the production of lactulose. These monosaccharides could be classified into two groups based on their time to arise and the reaction mechanism. The coloration of lactose was less than that of glucose and galactose, which are the constituents of lactose, due to degradants formed during their reaction in the subcritical phosphate buffer. Therefore, the application of a subcritical buffer solution would be suitable for the production of lactulose because of a small burden on the purification process. [Display omitted] • Lactose was converted to lactulose in subcritical phosphate buffer solution. • Buffer with an initial pH of 8.0 accomplished the maximum yield at 120 °C. • The maximum yield of 29% was obtained at 10 min as a reaction time. • The coloration of lactose was less than that of glucose and galactose. [ABSTRACT FROM AUTHOR]

This study aimed to assess the milk production data for New Zealand dairy goats in either a standard lactation (SL; ≤305 d in milk [DIM]) or extended lactation (EL; >305 and ≤670 DIM) using a random regression (RR) with third- and fifth-order Legendre polynomials, respectively. Persistency of EL was defined as (B/A) × 100, where A was the accumulated yield from d 1 to 305, and B was the accumulated yield from d 366 to 670. On average, goats in SL produced 1,183 kg of milk, 37 kg of fat, 37 kg of protein, and 54 kg of lactose. The average production of milk, fat, protein, and lactose in EL were 2,473 kg, 78 kg, 79 kg, and 112 kg, respectively. The average persistences for milk, fat, protein, and lactose yields during EL were 98%, 98%, 102%, and 96%, respectively. The relative prediction errors were close to 10% and the concordance correlation coefficients >0.92, indicating that the RR model with Legendre polynomials is adequate for modeling lactation curves for both SL and EL. Total yields and persistency were analyzed with a mixed model that included the fixed effects (year, month of kidding, parity, and proportion of Saanen) as covariates and the random effects of animal and residual errors. Effects of year, month of kidding, and parity were significant on the total yields of milk, fat, protein, and lactose for both SL and EL. The total milk yield of first-parity goats with SL was 946 kg and the total milk yield of second-parity goats with SL was 1,284 kg, making a total of 2,230 kg over 2 years. The total milk yield of a first-parity goat with EL was 2,140 kg. Thus, on average, a goat with SL for the first and second parity produced 90 kg more milk than a first-parity goat subjected to EL. However, a second-parity goat subjected to EL produced 43 kg more milk (2,639 kg) than a goat with SL following the second and third parity (1,284 kg + 1,312 kg). These data, along with the various other benefits of EL (e.g., fewer offspring born and reduced risk of mastitis, lameness, and metabolic problems in early lactation), indicate that EL as a management strategy holds the potential to improve dairy goat longevity and lifetime efficiency without compromising milk production. [ABSTRACT FROM AUTHOR]

The considerable increase in the production capacity of individual cows owing to both selective breeding and innovations in the dairy sector has posed challenges to management practices in terms of maintaining the nutritional and metabolic health status of dairy cows. In this observational study, we investigated the associations between milk yield, composition, and technological traits and a set of 21 blood biomarkers related to energy metabolism, liver function or hepatic damage, oxidative stress, and inflammation or innate immunity in a population of 1,369 high-yielding Holstein-Friesian dairy cows. The milk traits investigated in this study included 4 production traits (milk yield, fat yield, protein yield, daily milk energy output), 5 traits related to milk composition (fat, protein, casein, and lactose percentages and urea), 11 milk technological traits (5 milk coagulation properties and 6 curd-firming traits). All milk traits (i.e., production, composition, and technological traits) were analyzed according to a linear mixed model that included the days in milk, the parity order, and the blood metabolites (tested one at a time) as fixed effects and the herd and date of sampling as random effects. Our findings revealed that milk yield and daily milk energy output were positively and linearly associated with total cholesterol, nonesterified fatty acids, urea, aspartate aminotransferase, γ-glutamyl transferase, total bilirubin, albumin, and ferric-reducing antioxidant power, whereas they were negatively associated with glucose, creatinine, alkaline phosphatase, total reactive oxygen metabolites, and proinflammatory proteins (ceruloplasmin, haptoglobin, and myeloperoxidase). Regarding composition traits, the protein percentage was negatively associated with nonesterified fatty acids and β-hydroxybutyrate (BHB), while the fat percentage was positively associated with BHB, and negatively associated with paraoxonase. Moreover, we found that the lactose percentage increased with increasing cholesterol and albumin and decreased with increasing ceruloplasmin, haptoglobin, and myeloperoxidase. Milk urea increased with an increase in cholesterol, blood urea, nonesterified fatty acids, and BHB, and decreased with an increase in proinflammatory proteins. Finally, no association was found between the blood metabolites and milk coagulation properties and curd-firming traits. In conclusion, this study showed that variations in blood metabolites had strong associations with milk productivity traits, the lactose percentage, and milk urea, but no relationships with technological traits of milk. Specifically, increasing levels of proinflammatory and oxidative stress metabolites, such as ceruloplasmin, haptoglobin, myeloperoxidase, and total reactive oxygen metabolites, were shown to be associated with reductions in milk yield, daily milk energy output, lactose percentage, and milk urea. These results highlight the close connection between the metabolic and innate immunity status and production performance. This connection is not limited to specific clinical diseases or to the transition phase but manifests throughout the entire lactation. These outcomes emphasize the importance of identifying cows with subacute inflammatory and oxidative stress as a means of reducing metabolic impairments and avoiding milk fluctuations. [ABSTRACT FROM AUTHOR]

Lactose is typically produced via cooling crystallization either from whey or whey permeate (edible grade) or from aqueous solution (pharmaceutical grade). While in solution, lactose is present in 2 anomeric forms, α- and β-lactose. During cooling crystallization under standard process conditions, only α-lactose crystallizes, depleting the solution of α-anomer. In practice, mutarotation kinetics are often assumed to be much faster than crystallization. However, some literature reports limitation of crystallization by mutarotation. In the present research, we investigate the influence of operating conditions on mutarotation in lactose crystallization and explore the existence of an operation regimen where mutarotation can be disregarded in the crystallization process. Therefore, we study crystallization from aqueous lactose solutions by inline monitoring of concentrations of α- and β-lactose via attenuated total reflection Fourier-transform spectroscopy. By implementing a linear cooling profile of 9 K/h to a minimum temperature of 10°C, we measured a remarkable increase in β/α ratio, reaching a maximum of 2.19. This ratio exceeds the equilibrium level by 36%. However, when the same cooling profile was applied to a minimum temperature of 25°C, the deviation was significantly lower, with a maximum β/α ratio of 1.72, representing only an 8% deviation from equilibrium. We also performed a theoretical assessment of the influence of process parameters on crystallization kinetics. We conclude that mutarotation needs to be taken into consideration for efficient crystallization control if the crystal surface area and supersaturation are sufficiently high. [ABSTRACT FROM AUTHOR]

An improved agglomerate formulation with melatonin and fine lactose for dry powder inhalation using Turbuhaler® was developed. Co-grinding lactose with 1 % magnesium stearate prior to air jet mixing served as a key factor to improve the in vitro aerosolization and in vivo efficacy. Elevated mixing pressure facilitated the dispersion and homogenization of the cohesive mixture for even distribution of agglomerate size after spheroidization and subsequent higher emitted dose with lower variation. Magnesium stearate was employed as a tertiary component to adjust the interparticle force for better aerosolization. At optimized mixing pressure, co-grinding lactose with magnesium stearate before jet mixing displayed further improvement of fine particle fraction to 71.6 ± 3.1 %. The superior fine particle deposition efficiency contributed to rapid onset of action and a high bioavailability of 67.0 % after intratracheal administration to rats. Overall, an inhalable melatonin dry powder formulation exhibiting good aerosol property and lung deposition with clinical translation potential was developed. [Display omitted] • Ternary dry powder agglomerate formulation for inhalation was developed. • Air jet mixing efficiently disperses the cohesive mixture for spheroidization. • Elevated mixing pressure contributes to higher emitted dose with lower variation. • The fine particle fraction of 71.6 ± 3.1% for melatonin was achieved. • Rapid onset of action with a bioavailability of 67.0% was realized. [ABSTRACT FROM AUTHOR]

Cofactor imbalance obstructs the productivities of meta-bolically engineered cells. Herein, we employed a minimally perturbing system, xylose reductase and lactose (XR/lactose), to increase the levels of a pool of sugar phosphates which are connected to the biosynthesis of NAD(P)H, FAD, FMN, and ATP in Escherichia coli. The XR/lactose system could increase the amounts of the precursors of these cofactors and was tested with three different metabolically engineered cell systems (fatty alcohol biosynthesis, bioluminescence light generation, and alkane biosynthesis) with different cofactor demands. Productivities of these cells were increased 2-4-fold by the XR/lactose system. Untargeted metabolomic analysis revealed different metabolite patterns among these cells, demonstrating that only metabolites involved in relevant cofactor biosynthesis were altered. The results were also confirmed by transcriptomic analysis. Another sugar reducing system (glucose dehydrogenase) could also be used to increase fatty alcohol production but resulted in less yield enhancement than XR. This work demonstrates that the approach of increasing cellular sugar phosphates can be a generic tool to increase in vivo cofactor generation upon cellular demand for synthetic biology. [ABSTRACT FROM AUTHOR]

Our objectives were to determine the effect of fat (skim to whole milk) and protein (3.4%–10.5%) concentration on the sensory and physical properties of milk beverage base that had lactose and other low molecular components removed by ultrafiltration (UF). In experiment 1, a matrix of 16 treatments was produced to achieve 4 levels of lactose removal (0%, 30%, 70%, and 97%) at each of 4 fat levels (skim, 1%, 2%, and whole milk). In experiment 2, a matrix of 12 treatments was produced to achieve 4 levels of lactose removal (0%, 30%, 70%, and 97%) at each of 3 protein concentrations (3.4%, 6.5%, and 10.5% protein). Physical and sensory properties of these products were determined. Removal of >95% of milk lactose by UF required a diafiltration volume of approximately 3 times the milk volume. Lactose and low molecular weight solute removal increased whiteness across the range from skim to whole milk while decreasing viscosity and making milk flavor blander. In addition, lactose (and other low molecular weight solute) removal by UF decreased titratable acidity by more than 50% and increased milk pH at 20°C to >7.0. Future work on milk and milk-based beverages with lactose removed by UF needs to focus on interaction of the remaining milk solids with added flavorings, changing casein to whey protein ratio before removal of lactose by UF, and the effect of lactose and low molecular weight solute removal on heat stability, particularly for neutral-pH, shelf-stable milk-based beverages. [ABSTRACT FROM AUTHOR]

The discovery that certain cellobiose 2-epimerases (C2E) are capable of synthesizing lactulose and epilactose with high yield and selectivity has renewed the interest in their biological synthesis. In order to provide a valuable tool for the design and optimization of the synthesis of lactulose and epilactose with C2E as biocatalyst, the reaction is modeled here for the first time. Two competing reaction mechanisms, so called extended and reduced mechanisms, were proposed and their corresponding models developed. The extended mechanism was discarded because of the overfitting of the resulting model. The parameters of the reduced model were successfully estimated by no linear regression at 30, 40, 50, 60 and 70 °C, and the temperature dependence of the kinetic parameters was modeled by fitting them to Arrhenius and Vant Hoff-type equations. The reduced model showed a good fit to experimental data within the studied temperature range, well describing the course of reactions. [ABSTRACT FROM AUTHOR]

Lactose malabsorption is a very common condition due to intestinal lactase deficiency. Post weaning, a genetically programmed and irreversible reduction of lactase activity occurs in the majority of the world's population. Lactose malabsorption does not necessarily result in gastrointestinal symptoms, i.e. lactose intolerance, which occurs in approximately one third of those with lactase deficiency. In the absence of well-established guidelines, the common therapeutic approach tends to exclude milk and dairy products from the diet. However, this strategy may have serious nutritional disadvantages. Mainly in particular categories, such as the older adults, the approach to lactose malabsorption may deserve careful considerations. Milk and dairy products are an important supply of a wide range of nutrients that contribute to meet the nutritional needs in different life stages. Dietary composition can significantly impact the mechanisms leading to age-related loss of bone mineral density, skeletal muscle mass or function and overall risk of sarcopenia. Moreover, in the latest years, different lines of evidence have highlighted an association between dairy intake and prevention of chronic diseases as well as all-cause mortality. The aim of this opinion paper is to provide an overview of lactose malabsorption and intolerance in the older adults and their implications in clinical practice. [ABSTRACT FROM AUTHOR]

The fermentation process of milk to yoghurt using Lactobacillus delbrueckii subsp. bulgaricus in co-culture with Streptococcus thermophilus is hallmarked by the breakdown of lactose to organic acids such as lactate. This leads to a substantial decrease in pH - both in the medium, as well as cytosolic. The latter impairs metabolic activities due to the pH-dependence of enzymes, which compromises microbial growth. To quantitatively elucidate the impact of the acidification on metabolism of L. bulgaricus in an integrated way, we have developed a proton-dependent computational model of lactose metabolism and casein degradation based on experimental data. The model accounts for the influence of pH on enzyme activities as well as cellular growth and proliferation of the bacterial population. We used a machine learning approach to quantify the cell volume throughout fermentation. Simulation results show a decrease in metabolic flux with acidification of the cytosol. Additionally, the validated model predicts a similar metabolic behaviour within a wide range of non-limiting substrate concentrations. This computational model provides a deeper understanding of the intricate relationships between metabolic activity and acidification and paves the way for further optimization of yoghurt production under industrial settings. • Kinetic model that takes cell culture growth into account. • Integration of new experimental data sets. • Potential to predict acidification during batch culture growth. [ABSTRACT FROM AUTHOR]

Delactosed whey permeate is the mother liquor/by-product of lactose manufacture, but it still contains around 20 wt% lactose. The high mineral content, stickiness, and hygroscopic behavior prevent further recovery of lactose in the manufacturing process. Therefore, its use is currently limited to low-value applications such as cattle feed, and more often it is seen as waste. This study investigates a new separation technique operating at sub-zero conditions. At low temperature, precipitation of calcium phosphate is expected to be reduced and the lower solubility at sub-zero temperature makes it possible to recover a large portion of the lactose. We found that lactose could be crystallized at sub-zero conditions. The crystals had a tomahawk morphology and an average size of 23 and 31 µm. In the first 24 h, the amount of calcium phosphate precipitated was limited, whereas the lactose concentration was already close to saturation. The overall rate of crystallization was increased compared with the crystals recovered from a pure lactose solution. Mutarotation was rate limiting in the pure system but it did not limit the crystallization of lactose from delactosed whey permeate. This resulted in faster crystallization; after 24 h the yield was 85%. [ABSTRACT FROM AUTHOR]

The continuously increasing demand of lactic acid opens a window for the integration of membrane technology in the dairy industry, improving the sustainability by avoiding the use of large amounts of chemicals and waste generation. Lactic acid recovery from fermentation broth without precipitation has been studied by numerous processes. In this work, a commercial membrane with high lactose rejection and a moderate lactic acid rejection, enabling a permselectivity up to 40%, is sought to perform the simultaneous removal of lactic acid and lactose separation from the acidified sweet whey from mozzarella cheese production in a single stage. The AFC30 membrane of the thin film composite nanofiltration (NF) type was selected because of its high negative charge, low isoelectric point, and divalent ion rejection, as well as a lactose rejection higher than 98% and a lactic acid rejection lower than 37%, at pH 3.5, to minimize the need of additional separation steps. The experimental lactic acid rejection was evaluated at varying feed concentration, pressure, temperature, and flow rate. As the dissociation degree of lactic acid is negligible in industrially simulated conditions, the performance of this NF membrane was validated by the irreversible thermodynamic Kedem-Katchalsky and Spiegler-Kedem models, with the best prediction in the latter case, with the parameter values: L p = 3.24 ± 0.87 L × m−2 × h−1 × bar−1 and = 15.06 ± 3.17 L × m−2 × h−1, and σ = 0.45 ± 0.03. The results obtained in this work open the way for the up-scaling of membrane technology on the valorization of dairy effluents by simplifying the operation process and the model prediction and the choice of the membrane. [ABSTRACT FROM AUTHOR]

Lactose, the principal carbohydrate found in milk, plays an important role in the physiological processes of milk production because it is related to milk volume, and it is responsible for the osmotic equilibrium between blood and milk in the mammary gland. In this study, factors affecting lactose content (LC) in sheep milk are investigated. For this purpose, 2,358 test-day records were sampled from 509 ewes (3–7 records per animal). The LC and other main milk traits were analyzed using a mixed linear model that included days in milk (DIM) class, parity, lambing month, and type of lambing as fixed effects and animal, permanent environment, and flock test day as random effects. The pedigree-based approach was used to estimate the heritability and repeatability of LC. Moreover, the genomic background of LC was investigated through a GWAS. The LC was affected by all tested factors (i.e., DIM class, parity, lambing month, and type of lambing). Low heritability (0.10 ± 0.05) and moderate repeatability (0.42 ± 0.02) were estimated for LC. High negative genetic correlations were estimated between LC and NaCl (−0.99 ± 0.01) and between LC and somatic cell count (−0.94 ± 0.05). Only 2 markers passed the chromosome-wide Bonferroni threshold. Results of the present study, although obtained on a relatively small sample, suggest the possibility to include LC in the breeding programs, particularly because of its strong relationship with NaCl and somatic cell count. [ABSTRACT FROM AUTHOR]

Compact cylinders and prismatic bars of carbon-bonded alumina based on an environment-friendly lactose-tannin binder system with lactose to tannin mass ratios of 5:1, 4:1 and 3:1, completely free of the conventional but harmful pitch binder, were prepared by slip casting and uniaxial pressing, respectively. The specimens were characterized by their physical properties (density, porosity), residual carbon content as well as microstructural analysis. In addition, the rheological behavior of the slurries was studied in order to prepare the compacts by slip casting. Mechanical tests at room temperature and, in particular, at high temperatures up to 1400 °C under bending, compression and creep loading, were performed. The results showed a brittle-to-ductile transition at temperatures between 1100 °C and 1300 °C. The bending strength of the bars was significantly lower compared to previously reported pitch-based ones. Early hardening of the powder before pressing could greatly decrease the bending strength. During heating at 1500 °C, cracks occurred unexpectedly on bars to be tested, and some dark grey droplets were observed as well after cooling down. A possible reason is a synergetic interaction between structural change of the carbonaceous matrix and overheating triggered by the electromagnetic field of the inductive heating. [ABSTRACT FROM AUTHOR]

The composition of seasonal pasture-produced milk is influenced by stage of lactation, animal genetics, and nutrition, which affects milk nutritional profile and processing characteristics. The objective was to study the effect of lactation stage (early, mid, and late lactation) and diet on milk composition in an Irish spring calving dairy research herd from 2012 to 2020 using principal component and predictive analytics. Crude protein, casein, fat, and solids increased from 2012 to 2020, whereas lactose concentration peaked in 2017, then decreased. Based on seasonal data from 2013 to 2016, forecasting models were successfully created to predict milk composition for 2017 to 2020. The diet of cows in this study is dependent upon grass growth rates across the milk production season, which in turn, are influenced by weather patterns, whereby extreme weather conditions (rainfall and temperature) were correlated with decreasing grass growth and increasing nonprotein nitrogen levels in milk. The study demonstrates a significant change in milk composition since 2012 and highlights the effect that seasonal changes such as weather and grass growth have on milk composition of pasture-based systems. The potential to forecast milk composition at different stages of lactation benefits processers by facilitating the optimization of in-process and supply logistics of dairy products. [ABSTRACT FROM AUTHOR]

Colostrum quality is generally defined by the IgG concentration in colostrum, and many methods have been used to assess it. Methods to measure colostrum quality both in the laboratory and in the field have been validated in cattle; however, this is only a recent topic of interest for sheep colostrum. Laboratory-based methods are often time consuming and require trained personnel compared with new handheld evaluation tools such as the digital Brix refractometer, which gives real-time results. The aims of this study were to (1) evaluate the relationship between the digital Brix refractometer and constituents indicative of quality (IgG, protein, fat, and lactose) in colostrum and transition milk, and (2) determine an appropriate Brix % cut-off value for the Brix refractometer in sheep colostrum and transition milk. The study used 50 colostrum samples (collected at 0 h postpartum, before lambs' sucking) and 169 transitional milk samples (collected at 4 and 24 h postpartum, after lambs had sucked) collected over 6 lambing trials in 2 years (2019 and 2020). We concluded that the Brix refractometer results correlated weakly with IgG concentration determined by radial immunodiffusion assay in colostrum collected at 0 h postpartum (r = 0.11) and in transition milk collected at 4 h postpartum (r = 0.12); however, a moderate to strong correlation was shown in transition milk samples collected at 24 h (r = 0.66). Brix % was significantly correlated with fat %, lactose %, and protein % at all timepoints. To determine an appropriate Brix % cut-off value indicating an IgG concentration of 20 mg/mL, we analyzed sensitivity and specificity of the Brix refractometer at 0, 4, and 24 h. In samples collected at 0 and 4 h, the highest combination of sensitivity, specificity, and accuracy was achieved at a Brix % cut-off value of 29%; in samples collected at 24 h postpartum, a Brix % cut-off value of 27% gave the highest sensitivity, specificity, and accuracy. Overall, the Brix refractometer has potential as a useful in-field tool for researchers and producers in both extensively and intensively managed flocks to measure and determine the quality of sheep colostrum and transition milk. [ABSTRACT FROM AUTHOR]

Lactosucrose (LS) is a prebiotic trisaccharide enzymatically synthesized by transglycosylation from lactose and sucrose with beneficial health effect. The β-fructofuranosidase used for synthesis of LS was produced from Bacillus methanolicus LB-1, which was isolated from traditional rice wine. A maximal yield of 8.63 U/mL of the enzyme was obtained by fermentation with B. methanolicus LB-1 under the optimized conditions: 10 g/L of glucose, 5 g/L of yeast extract, initial medium pH at 7.0, 37 °C, 24 h. The enzyme was purified and identified by ammonium sulfate fractional precipitation, Sephadex G-75 gel filtration chromatography and LC-MS, and SDS-PAGE of the purified enzyme showed a major protein band at 45 kDa. Biosynthesis of LS was performed using the purified β-fructofuranosidase, and production of LS reached 110 g/L under the optimized reaction conditions: pH at 7.0, 37 °C, 6.0 U/g sucrose of enzyme, 15% of sucrose, 15% of lactose, 28 h. HPLC analysis of the reaction products showed a distinct peak for LS at about 30 min of elution, confirming that B. methanolicus LB-1 β-fructofuranosidase had effective transfructosylation activity. Therefore, this new microbial source of β-fructofuranosidase may be a candidate with potential application prospect in biosynthesis of prebiotic LS. [Display omitted] • A novel strain of Bacillus methanolicus LB-1 was firstly found to possess β-fructofuranosidase activity. • The production of β-fructofuranosidase was optimized and the enzyme was purified. • The novel β-fructofuranosidase producing strain was used to synthesize lactosucrose. • The biosynthesis conditions of lactosucrose were optimized. [ABSTRACT FROM AUTHOR]

Rift Valley Fever virus (RVFV) causes the zoonotic RVF disease, which results in substantial economic losses in livestock industries. Regular vaccination of livestock against RVF is necessary to generate long-term immunity and avoid the loss of livestock. The live attenuated vaccine based on Clone 13 virus strain has been used to reduce the negative impact of RVF disease. The vaccine strain is heat labile and requires stringent conditions for storage and handling. This research evaluated lactose and sucrose-based stabilizers coupled with lyophilisation to enhance stability of the RVF Clone 13 vaccine strain. The glass transition temperature (Tg) of the sucrose-RVF vaccine was 97.0 °C with average residual moisture of below 2 %. The lactose formulation was characterised with Tg of 83.5 °C and residual moisture of above 2 %. The RVF Clone 13 sucrose-based formulation maintained higher antigen titres during lyophilisation compared to the lactose-formulated vaccine. Cellular-mediated and humoral immunity was evaluated and compared for the two newly formulated vaccines. Pheroid® technology was also investigated as a potential adjuvant and its ability to further enhance the immunogenicity conferred by the RVF Clone 13 vaccine formulations in Merino sheep. No adverse reactions were observed following injection of the vaccine formulations in mice, guinea pigs and Merino sheep. Comparable protective humoral immune responses against RVF were obtained for all animals vaccinated with the lactose and sucrose-based stabilisers with and without the Pheroid® adjuvant. No proliferation of CD8+ and CD4+ T-cells as well as expression of IFN-γ was observed for all animals group vaccinated with Pheroid® only. Specific CD8+ IFN-γ+T–cells were expressed at higher levels compared to the CD4+ IFN-γ+T–cells in the RVF Clone 13 vaccines, suggesting that cellular immunity against RVF is through the Class I antigen presentation pathway. [ABSTRACT FROM AUTHOR]

Lacto- N -fucopentaose III (LNFP III) is a human milk oligosaccharide (HMO) with potential health benefits in infants, including in immune development and modulation of the intestinal environment. Low-cost fermentative production of various HMOs from lactose by engineered Escherichia coli has attracted attention, but few reports have investigated long-chain HMO production, such as of the pentasaccharide LNFP III. LNFP III is synthesized by α1,3-fucosyltransfer reaction to the glucosamine (GlcNAc) moiety in the lacto- N -neotetraose (LNnT) skeleton by α1,3-fucosyltransferase (α1,3-FucT). However, the known α1,3-FucTs also transfer fucose to the reducing terminal glucose moiety of LNnT or the starting material lactose, resulting in various byproducts. Here, we found a useful α1,3-FucT from Parabacteroides goldsteinii (PgsFucT), which is only reactive for GlcNAc in the N -acetyllactosamine (LacNAc) skeleton in vivo. On the basis of sequence alignment with a FucT of known structure, we also generated α1,3-FucT variants with altered reactivity for LacNAc or lactose. An E. coli strain heterologously expressing PgsFucT accumulated 3.84 g/L of LNFP III after 48 h of culture in a 3-L jar-fermenter. The amounts of various byproduct sugars were remarkably decreased compared with a strain expressing the previously characterized α1,3-fucT from Bacteroides fragilis. [Display omitted] • A novel α1,3-fucosyltransferase from Parabacteroides goldsteinii (PgsFucT) was found. • PgsFucT only modifies N -acetyllactosamine (LacNAc) and cannot modify lactose. • PgsFucT mutants were generated with altered reactivity for LacNAc or lactose. • Lacto- N -fucopentaose III (LNFP III) was efficiently produced in E. coli using PgsFucT. [ABSTRACT FROM AUTHOR]

Necro-hemorrhagic enteritis in calves, caused by Clostridium perfringens type A, is a fatal disease, mostly affecting calves in intensive rearing systems. The lack of development of active immunity against α toxin, an essential virulence factor in the pathogenesis, has been proposed as a main trigger. In this experimental study, the effect of a set of milk replacer components on α toxin production, and the effect of lactose on in vivo antibody production, were investigated. For the latter, Holstein-Friesian bull calves (n = 18) were fed an all liquid diet that contained either a milk replacer with high-lactose content (45% DM) or the same milk replacer that was lactase treated, resulting in a lactose-free equivalent. Antibody levels against α toxin were monitored from 2 to 12 wk of age. In the in vitro part of the study, a concentration-dependent inhibitory effect of lactose on in vitro C. perfringens α toxin activity was observed, whereas protein did not influence α toxin activity. The in vivo experiment then showed from the age of 10 wk onwards, that anti-α toxin antibody levels of high-lactose animals declined, whereas antibody levels of the animals consuming lactose-free milk replacer remained the same throughout the trial. This points to a natural decline in maternal immunity of lactose-consuming animals, that is not compensated by the development of an active immunity, resulting in inferior protection. This study suggests that dietary lactose reduces C. perfringens α toxin production in vivo, which may lead to a decreased antigen presentation and thus lower serum antibody levels against the toxin. Consequently, any event causing massive α toxin production puts lactose-consuming calves at higher risk of developing necro-hemorrhagic enteritis. [ABSTRACT FROM AUTHOR]

Background Probiotics may alleviate lactose maldigestion. Objectives The objective was to select a probiotic with high lactase activity and compare it with lactase and placebo in clinical trials. Methods Bacterial cultures were screened for lactase activity in a model of the upper gastrointestinal (GI) tract. Bifidobacterium animalis subsp. lactis Bi-07 (Bi-07) counts were adjusted in subsequent experiments to correspond to 4500 Food Chemicals Codex (FCC) units of lactase, the amount in the European Food Safety Authority (EFSA)-approved health claim. Two crossover clinical trials, Booster Alpha and Booster Omega, were performed in participants with lactose intolerance, where 2 × 1012 CFUs Bi-07, 4662 FCC lactase, or placebo was consumed simultaneously with a lactose challenge, with 1-wk washouts between challenges. The trial designs were identical except for the source of lactose. Breath hydrogen concentration (BHC) was measured to assess the effect of the investigational products on lactose digestion, for which incremental area under the curve (iAUC) was the primary outcome. Peak BHC, cumulative BHC, and GI symptoms were secondary outcomes. Results Bi-07 was superior to placebo in reducing BHC [iAUC, parts per million (ppm) ∙ h] in both trials (Booster Alpha: geometric least square mean ratio: 0.462; 95% CI: 0.249, 0.859; P =  0.016; Booster Omega: 0.227; 95% CI: 0.095, 0.543; P  = 0.001). Lactase was superior to placebo in Booster Alpha (0.190; 95% CI: 0.102, 0.365; P  < 0.001) but not Booster Omega (0.493; 95% CI: 0.210, 1.156; P  = 0.102). Noninferiority of Bi-07 compared with lactase was observed in Booster Omega (0.460; 95% CI: 0.193, 1.096; P  = 0.079; CI upper limit < 1.25 noninferiority margin). Odds of abdominal pain (compared with placebo: 0.32, P  = 0.036) and flatulence (compared with placebo: 0.25, P  = 0.007) were lower with lactase in Booster Alpha. Increased odds of nausea were seen with Bi-07 (compared with placebo: 4.0, P  = 0.005) in Booster Omega. Conclusions Bi-07 has high lactase activit y , and in 2 clinical trials, it supported lactose digestion in individuals with lactose intolerance. These trials were registered at clinicaltrials.gov as NCT03659747 (Booster Alpha) and NCT03814668 (Booster Omega). [ABSTRACT FROM AUTHOR]

• This study showcases a robust multi-sugar identification system's efficacy in swiftly detecting sugars. • The biosensor system exhibits selective affinity towards different sugars, enabling identification without overlap. • Distinct characteristic peaks for each sugar facilitate efficient detection within a multi-sugar environment. The swift and accurate diagnosis of diseases, particularly diabetes, remains a pressing and critical concern in healthcare. Monitoring blood glucose levels is imperative for diabetic patients to manage their condition effectively. Addressing this necessity, developing non-invasive, simultaneous detection devices for sugars shows immense promise. Herein, we introduce the design of a novel nano-biosensor employing edge‐functionalized graphene quantum dots, enabling the concurrent detection of three pivotal sugars: glucose, galactose, and lactose. Through comprehensive molecular dynamics simulations, we demonstrate the feasibility and stability of the proposed biosensor. Our results show that the edge-functionalization of graphene quantum dots significantly enhances their binding affinity, with calculated average number of contacts of 2174 for glucose, 1085 for galactose, and 6274 for lactose. Furthermore, the radial distribution function analysis echoed these findings, highlighting lactose's pronounced interaction with the biosensor, followed by glucose and then galactose. The detailed analysis reveals distinct and non-overlapping sugar bindings on the nano-biosensor surface, with lactose showing the highest affinity and interaction strength, followed by glucose and galactose. This innovative approach marks a significant stride forward in biosensor technology, providing a potential avenue for precise and dependable monitoring of blood sugar levels in diabetic patients. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pasteurized fig purée changes fermented milk technological properties and stability. • Consumer acceptance of fermented milk was affected by the percentage of pasteurized fig purée. • 30 % and 40 % of pasteurized fig purée is a suitable content to develop no-added sugar fermented milks. The development of new fermented milks formulations enriched with fruit by-products may widen the existing market offer of products matching consumer demands on novel, and " no artificial added sugars " products. Unmarketable fig fruit, food by-product, could be considered as a potential ingredient to develop a new dairy product. The aim of this study was to study the consumer acceptance of fermented milk enriched with different percentage of pasteurized fig purée (by-products) and their technological properties. It was found that the quantity of fig puree added influenced fermented milks texture and spontaneous syneresis. Formulations containing 40% fig puree showed the highest values of firmness, consistency, cohesiveness, and viscosity index with improvements seen from 20% fig puree addition. Furthermore, the inclusion of fig puree in fermented milks reduced the levels of lactic acid bacteria comparing with control samples, but the microbial load was higher than 106 UFC g−1 LAB (estimated counts in MRS) and 9 UFC g−1 LAC (estimated counts in M17). Polyphenolic content increased with fig puree percentage, enhancing antioxidant activity. Volatile compound analysis identified hexanoic acid, acetoin, and butanoic acid as predominant in enriched fermented milks. It is also worth highlighting that sensory evaluation revealed better ratings for texture and sweetness acceptance in formulations containing 30% and 40% of fig puree, correlating with instrumental data. Overall, the quality parameters were maintained and even improved, leading to high consumer acceptability ratings. [ABSTRACT FROM AUTHOR]

Many industrial food processes are multi-steps, multi-products systems, and sharing the environmental impacts produced by each step to each product is critical when implementing life cycle assessment (LCA) method. The objective of the study was therefore to investigate subdivision and different allocation rules as means of accounting for branched process itineraries such as the fractionation of milk into cream, casein, whey proteins and lactose as a case study. Depending on the mass, dry matter, protein or economic allocation, single products may or may not bear significant environmental impacts, thereby stressing the need for equally detailed inventories for all co-products. Aggregating the results by step or by input further helps identifying hotspots. Methodological choices in LCA of multifunctional systems are therefore strategic decisions that ultimately affect the eco-design of products, processes and food chains. • Sharing environmental impacts between up to 5 co-products is an issue in food systems. • Subdivision helps accounting for multi-product i.e. branched processing itineraries. • LCA's sensitivity to allocation or aggregation rules helps identifying the hotspots. • Transparent rules are necessary to compare products' environmental footprints. [ABSTRACT FROM AUTHOR]

The production of the sugars fructose and lactulose from lactose using the enzymes β-galactosidase and glucose isomerase immobilized on bacterial cellulose (BC) membranes has been investigated. Lactose is hydrolyzed by β-galactosidase at 30 °C to glucose and galactose at a high conversion rate, while at the same temperature, glucose isomerase is not effective in converting the produced glucose to fructose. The rate of the isomerization reaction of glucose to fructose at 70 °C has been studied. Two types of enzyme immobilization were investigated: immobilization in one stage and immobilization in two stages. The results showed that BC membrane increased three-fold the yield and the reaction rate of fructose and lactulose production from lactose. The noteworthy enhancement of BC membranes' impact on the isomerization reaction by immobilized enzymes grants permission for a novel research avenue within the context of white biotechnology development. Additionally, this effect amplifies the role of BC in sustainability and the circular economy. • BC membranes as carrier for β-galactosidase and glucose isomerase immobilization. • Immobilization in one or two stages addition of enzymes into lactose medium. • Fructose and lactulose from lactose using immobilized enzymes on BC membranes. • Three times increase of fructose and lactulose production yield from lactose. • Promotion effect of BC membranes as carrier of immobilized enzymes. [ABSTRACT FROM AUTHOR]

[Display omitted] Magnesium stearate (MgSt) and lactose fines are often used as ternary components in carrier-based dry powder inhalers (DPIs) to improve fine particle fraction (FPF), but whether they act synergistically to improve aerosolization performance of DPI formulations is currently less studied. In addition, the applicability of utilizing powder rheological parameters to predict the FPF needs to be further verified. Thus, in this study, using fluticasone propionate (FP) as a model drug, effect of lactose fines addition in 0.5% MgSt containing DPI formulations on their powder and aerodynamic properties was explored. Influence of MgSt and fines mixing order on the DPIs performance was also investigated. The results showed that addition of lactose fines (1–10%) in 0.5% MgSt containing formulations could further improve flowability and enhance adhesion of the mixtures, and they could act synergistically to improve FPF. Moreover, the presence of 0.5% MgSt can greatly reduce the amount of lactose fines required to achieve the comparable FPF. The mixing order can affect distribution of MgSt on the carrier surface, with higher FPF noted when MgSt was mixed with carrier first, followed by lactose fines. A good linear relationship between powder rheological parameters such as basic flowability energy (BFE), Permeability and FPF was disclosed. In conclusion, in FP based DPIs, MgSt and lactose fines act synergistically to enhance FPF by tuning powder characteristics. Good flowability (27.39%) and strong adhesion (72.61%) contributed to the enhanced drug deposition in the lung. [ABSTRACT FROM AUTHOR]

• Our manuscript develops a fingerprint spectrum sensing platform based on a dual resonance device that can determine the analytes as well as the concentration from the frequency shift and amplitude change of the two resonance dips at different polarization modes and angles of incidence. • Our technology allows the multi-dimensional characterization of analytes for fingerprint spectrum sensing without introducing antibodies and replacing metasurfaces, providing a convenient and versatile platform for biochemical sensing. Terahertz (THz) label-free metasurface sensors have attracted great attention in the biochemical field, and fingerprint spectral sensing provides a powerful tool for the detection of trace analytes. In this study, we demonstrated a method based on a dual resonance metasurface sensor that enabled the identification of α-lactose, cis -azobenzene (cis -AB), and trans -azobenzene (trans -AB), as well as their concentration detection. By changing the angle of incidence and direction of polarization of THz wave on the metasurface covering analyte, the double resonance dips would be changed, and the spectral changes due to the changes in these parameters would be summarized on the radargrams, the sensor provided different THz fingerprint spectrums for each sample even without introducing antibodies. Our results provide a convenient route for fingerprint spectrum identification of biochemical molecules. [ABSTRACT FROM AUTHOR]

The high-demand rare sugars d -tagatose and d -allulose may be produced from lactose in a combined process, though this dual conversion has not yet been demonstrated. Four enzymes from thermophilic organisms were cloned and expressed in Escherichia coli to synthesize d -tagatose and d -allulose from lactose: β-galactosidase (Geobacillus stearothermophilus), l -arabinose isomerase (G. stearothermophilus US100), d -glucose isomerase (Weizmannia coagulans) and d -allulose epimerase (Arthrobacter globiformis). A single-pot reaction mixture yielded 9.9 ± 1.5 mg mL−1 d -allulose and 10.7 ± 1.1 mg mL−1 d -tagatose after 24 h at 70 °C. Enzyme addition order did not have an impact on yields (p = 0.3527). Higher lactose concentrations resulted in higher d -tagatose concentrations (p ≤ 0.001) regardless of when the lactose was added, however, specific yields for d -allulose were higher without adding additional lactose during the reaction (p ≤ 0.001). These experiments demonstrate that a single pot synthesis of d -tagatose and d -allulose is feasible and with more optimization could be used in industrial applications. [ABSTRACT FROM AUTHOR]

A simple technique was used to create a composite material made of graphitic carbon nitride supported on magnetic chitosan (g-C 3 N 4 /MNP/CS). This substance was employed in the structure of a surface plasmon resonance (SPR) lactose biosensor as a modifier for a thin layer of gold and as a support for the covalent stabilization of cellobiose dehydrogenase. The Finite-Difference Time-Domain (FDTD) approach was used to mimic the sensor's evanescent field in order to examine the SPR behavior. Additionally XRD and SEM techniques were used to examine the shape of MNPs/CS/g-C 3 N 4 and the intended sensor's SPR behavior. It can be used in the food industry, with a detection limit of 5 μM and a linear range of 0.01–100 mM‏ The biosensor is extremely sensitive, demonstrating its accuracy in lactose detection. [ABSTRACT FROM AUTHOR]

[Display omitted] A new theory for the dispersibility enhancing effect of excipient fines for adhesive mixtures for inhalation is presented in this paper, while at the same time the shortcomings of current hypotheses are discussed. The proposed mechanism, denoted the 'viscoelastic damping effect', states that the presence of fines particles acts to dampen the collisions between carrier particles during mixing. As a consequence, fewer fine particles are 'irreversibly' pressed into the carriers, which in turn entails a higher fine particle fraction. The mechanism was demonstrated experimentally at different levels of added lactose fines by studying the influence of processing on fine particle fraction. This approach furthermore enabled quantification of the effect. All fine particles present in the blend (APIs and excipient fines) act together to exert the damping effect. The proposed mechanism is able to explain the main body of published data, including the effect of added excipient fines, the effect of an increased drug load, and the effect of removal of carrier fines. The viscoelastic damping mechanism is general in nature and conveys a broader and more general understanding of the behavior of adhesive mixtures for inhalation. [ABSTRACT FROM AUTHOR]

There has been recent interest in using the β-galactosidase of Aspergillus oryzae to produce lactulose and fructosyl-galactooligosaccharides, for use as prebiotics. The success of the enzymatic process depends on the selectivities of the enzyme for the various transgalactosylation and hydrolysis reactions that occur in these systems, but the methods that have been used to date to express these selectivities are not adequate. In the current work, we demonstrate a method for determining the selectivity of the β-galactosidase of A. oryzae in two case studies done with literature data: (1) the production of lactulose from a mixture of lactose and fructose and (2) the production of fructosyl-galactooligosaccharides (fGOS) from lactulose. In the first case study, we demonstrate that the enzyme has a 4- to 5-fold preference for producing GOS over lactulose when an equimolar mixture of fructose to lactose is used, but that the selectivity for producing lactulose increases as the initial fructose to lactose molar ratio increases. In the second case study, we show that the enzyme has about a 1.5-fold preference for producing fGOS4 and fGOS5 over the initial transgalactosylation product, fGOS3. The selectivities that we determine in our work will be important parameters for time-based models used to guide the development and optimization of processes for the production of lactulose and fructosyl-galactooligosaccharides as prebiotics. [Display omitted] • Literature data was analyzed to determine selectivities in two reactions. • The 1st reaction involves production of lactulose from lactose and fructose. • However, selectivity for lactulose is 5-fold lower than that for galactooligosaccharides. • The 2nd reaction is production of fructosyl-galactooligosaccharides from lactulose. • The selectivity is slightly higher for longer chain fructosyl-galactooligosaccharides. [ABSTRACT FROM AUTHOR]

One of the main limitations of commercial production of algae is the cost of cultivation, largely attributed to the cost of the nutrients; hence, finding cheap alternative substrates has been a significant line of research in this field. The dairy industry produces large amounts of wastewater that might be used as a cost-effective nutrient alternative, containing lactose as a main carbon source, as well as other essential nutrients like nitrogen and phosphate. Nevertheless, just a few algal species of commercial value can grow on any organic carbon sources, and even less are able to utilize lactose. In this work we have identified a Parachlorella kessleri strain capable of utilizing lactose for growth, and have characterized its ability to accumulate metabolites of commercial interest under heterotrophic growth conditions. P. kessleri was capable to utilize lactose from dairy wastewater, and to accumulate several amino acids, dicarboxylic acids, such as tartaric acid and succinic acid, and triacylglycerols in heterotrophic conditions. These metabolites have applications in the food, feed, and pharmaceutical industries, and in the green chemical industry for the production of bio-based green polymers and biofuels. The significance of these findings for future product development is discussed. [Display omitted] • A Parachlorella kessleri strain selected able to utilize lactose for growth. • The strain's ability to grow on dairy wastewater confirmed. • Metabolites of commercial interest accumulated in heterotrophic conditions. • Metabolites relevant for the green industry also accumulated. [ABSTRACT FROM AUTHOR]

The wine market has always faced the problem of fraud, including the addition of exogenous sugar solutions to grape musts to increase the final alcohol content. Since in some countries the practice of chaptalization is prohibited (except by adding concentrated must) it is necessary to broaden the analytical techniques that allow the identification of this type of fraud. The aim of this study was to define an NMR-based sugar profile of genuine grape must to set concentration limits for each sugar as parameters of authenticity. Glucose, fructose, together with eleven minor sugars were quantified in 82 genuine Italian grape musts, developing an analytical procedure based on highly selective chemical shift filters followed by TOCSY. Alongside the characteristic myo - and scyllo -inositol, significant contents of mannose, galactose, and trehalose were also found. Otherwise, maltose, rhamnose, arabinose, sucrose and lactose are present in lower concentrations and show great concentration variability. • The sugar profile of grape must was defined by NMR. • The concentration natural limits of minor sugars are defined as parameter of authenticity of grape must. • Myo -, scyllo -inositol, galactose, mannose and trehalose: the most representative sugars of grape must. [ABSTRACT FROM AUTHOR]

Ensuring temporal and spatial uniformity in the chamber of a capsule filling machine with vacuum drum is crucial for consistent dosing to in-row capsules. A stirrer must induce axial mixing to maintain a homogeneous powder bed and prevent accumulation in specific regions, primarily caused by the feeding system above the chamber. To achieve satisfactory filling, the performance of different stirrers was analysed using a tracer particle strategy. This contribution introduces a lactose dyeing process, preventing agglomerate formation and yielding minimal differences in powder properties. Four lactose grades, exhibiting diverse particle sizes and flow behaviours, were dyed with methylene blue. A comprehensive analysis of lactose properties, such as particle size, density, and flow behaviour, confirms minimal alterations post-dyeing. Tracers obtained through this process reveal that a spike-type stirrer induces more axial mixing compared to a wire-type stirrer. The dyed lactose tracers effectively contribute to understanding and optimising the capsule filling process. [Display omitted] • Dyeing process for lactose tracers, ensuring minimal property deviation. • In-depth pre/post-dyeing analysis including material characterization and flow properties. • Tracer powder concentration was accurately quantified with UV–Vis spectroscopy. • Study of axial mixing in capsule filling machine using different stirrers. • Dyed lactose obtained can be used to further analyse the capsule filling process. [ABSTRACT FROM AUTHOR]

Sodium alkylbenzenesulfonate (LAS) is the most widely used anionic surfactant in the manufacture of commercial detergents due to its excellent detergent properties and low cost. However, they are highly polluting products due to their chemical composition, causing a serious problem of pollution and eutrophication in natural bodies of water, if the amount dumped and the frequency with which they are dumped is taken into account. In addition, damage to health and ecosystems by remaining in the environment for a long time, is a relevant issue of immediate attention. This article presents the results found when using lactose as a co-substrate on the simultaneous biodegradation of the LAS surfactant in an arrangement of UASB-type anaerobic reactors in two stages; with a hydraulic retention time of 0.25 days in the acidogenic reactor in which two surfactant concentration rates were evaluated: 200 ± 0.49 mg/L with an organic load of 5.92 ± 0.5 KgCOD/m3.d (experiments II, III and V) and 300 ± 0.05 mg/L with organic loading. of 6.8 ± 0.11 KgCOD/m3.d (experiment VI) and of one day, in the methanogenic reactor. The results showed that the acidogenic reactor was able to eliminate COD by 42.24% and biodegrade LAS by 86.65% (experiment V). At 300 mg/L (experiment VI), these values are reduced to 36.6 and 55% respectively. For its part, the methanogenic reactor fed with the effluent of the acidogenic reactor (experiment V) with a lower concentration of COD, LAS and organic load, showed a COD removal and LAS biodegradation efficiency of 83.17 and 13.85% respectively. [Display omitted] • The use of reactors in stages allows better control in the simultaneous biodegradation of LAS. • Lactose as a co-substrate developed acidogenesis conditions in the system studied. • With the conditions of acidogenesis and methanogenesis, the biomass of the reactors was not inhibited. • The acidogenic reactor is more robust than the methanogenic reactor, against the surfactant. • Anaerobic digestion is an alternative to biodegrade surfactants from wastewater. [ABSTRACT FROM AUTHOR]

The synthesis of novel prebiotics has gained attention due to a greater interest in intestinal health. In this study, lactosucrose was produced by levansucrase (LS, EC 2.4.1.10) catalyzing the transfructosylation of sucrose and lactose with whey (WP) and milk permeate (MP) as lactose sources. Selected functionalized supports were investigated for the immobilization of LSs from Gluconobacter oxydans (LS1) and Vibrio natriegens (LS2) by heterofunctional attachment. The highest immobilization protein yields of 94 % and 87 % and retained activities of 55 % and 98 %, respectively, were achieved upon the immobilization of LS1 and LS2 on RelizymeTM EP403/S functionalized with iminodiacetic acid (IDA)-cupric ions (Cu2+). The immobilization of LSs enhanced the reaction selectivity towards transfructosylation. Moreover, post-immobilization treatments (alkaline pH incubation, polyethylenimine (PEI) cross-linking) impacted the enzyme activity of the immobilized enzymes resulting in lower retained activities (11–74 %) but allowed them to achieve a higher thermal stabilization (up to 53 times increase), particularly with the high pH treated immobilized V. natriegens LS2. The identified optimal conditions for lactosucrose synthesis with high selectivity by free and immobilized RelizymeTM EP403/IDA-Cu immobilized LS2 resulted in 117 and 101 g/L, respectively, using WP as a lactose source. Lastly, the RelizymeTM EP403/IDA-Cu immobilized LS2 was successfully reused 3 consecutive times. [Display omitted] • Levansucrases (LSs) showed higher efficiency for transfructosylation bioconversion upon immobilisation. • Relizyme™ EP403 support functionalized with IDA-Cu provided the highest immobilization efficiency of LSs. • Post-immobilization treatments (high pH & PEI crosslinking) provided further thermal stabilization of LSs. • The highest bioconversion of dairy by-products into lactosucrose was achieved with immobilized V. natriegens LS2. • Reaction time and substrate ratio were significant in modulating bioconversion of whey permeate into lactosucrose. [ABSTRACT FROM AUTHOR]

The Maillard reaction (MR), under proper environmental conditions, has been used to improve protein functionality. In the present work, 2 high temperatures (50–80°C) and water activity (Aw; 0.45–0.67) were used to promote exogenous glycosylation of glycomacropeptide (GMP) while minimizing processing times (0, 8, 24, 48, and 96 h at 50°C; 0, 2, 4, 8, and 24 h at 80°C). Maltodextrin, a polysaccharide commonly used in the food industry as a functional ingredient, was used as a reducing sugar, and compared with lactose, a native milk sugar. The progression of MR was evaluated by tracking changes in molecular weight using SDS-PAGE, the formation of Amadori compounds, and browning. Aqueous glycosylated GMP solutions (5 to 20% wt/vol) were tested for solubility, rheological properties, and foam formation. As expected, MR progression was faster with Aw = 0.67 and 80°C. Glycosylated GMP powders showed no change in their solubility after MR. However, the apparent viscosity (γ ˙ = 30 s - 1) of the 20% wt/vol suspensions exhibited a slight increase when GMP was glycosylated with maltodextrin for 24 h at 80°C, and a 2-log increase when GMP was glycosylated with lactose, with a high browning development in both cases. The foam expansion index of the resuspended glycosylated powders was increased by between 25 and 66% compared with the nonglycosylated powders. Better foam stability (approximately 2 h) and no browning development were observed for GMP glycosylated with maltodextrin for 2 h at Aw = 0.67 and 80°C. The results show that GMP has undergone further glycosylation by means of controlled MR, which improves viscosity and foaming index without negatively affecting solubility. These preliminary studies provide a basis for the future creation of a new ingredient with GMP and reducing sugars. [ABSTRACT FROM AUTHOR]

Particle breakage of dairy powders occurs easily during many processes, reducing the powder functionality. The characteristics of particles and the applied stress from processing conditions on the particles are 2 main factors that can be manipulated to reduce breakage. In this study, we explored the effect of whey protein and lactose contents on dynamic breakage in agglomerated whey protein-lactose powders to provide useful information, in terms of particle characteristics, for controlling unwanted dairy powder breakage. A series of model agglomerates with different whey protein:lactose ratios were produced under the same spray-drying conditions, through a pilot plant trial. We evaluated physical characteristics, composition, and structure of samples; analyzed dynamic breakage under different mechanical stresses; and investigated the rehydration and water adsorption properties of model powders before and after breakage. The particle size and irregularity of agglomerates with more lactose was significantly higher than of samples that contained more protein. This resulted in higher particle breakage during dynamic breakage for samples with more lactose. The breakage of agglomerates was affected by the moisture content of powders and fatigue, where particle breakage happens when mechanical loads, lower than the strength of particles, occur multiple times. Breakage changed the morphology and surface composition of particles and decreased particle size. It also decreased the dispersibility of powders and increased the wetting time of wettable samples but decreased the wetting time of powders with poor wettability. Breakage accelerated time-dependent crystallization and decreased the crystallization temperature but did not affect the glass transition temperature of samples. Thus, under the same drying conditions, composition of powders significantly affected breakage, mainly by altering the physical properties of their particles, which resulted in deteriorated functionality. [Display omitted] [ABSTRACT FROM AUTHOR]

The β-galactosidase was extracted and purified from 100 g of C. arvensis seeds using a variety of protein purification procedures such as ammonium sulphate fractionation, gel filtration, and finally chromatography on a cationic ion exchanger. The effects of metal ions, kinetics parameters, and glycoprotein nature were determined, as well as the optimal pH and temperature of the purified enzyme. With a high specific activity (72 units/mg), β-galactosidase was isolated to a 24-fold apparent electrophoretic homogeneity. The molecular mass of β-galactosidase was determined as monomeric, which was further confirmed by SDS-PAGE and MALDI-TOF/MS analysis, with a 45 kDa molecular weight. The enzyme has a K m of 0.33 mM and a V max of 42 μmol/min Lactose in milk was reduced by 38.5 and 70 % after 4 h of incubation with β-galactosidase from C. arvensis. The β-galactosidase thermal inactivation kinetic parameters Δ H° , Δ S° , and Δ G° were calculated, indicating that the enzyme undergoes significant unfolding events during denaturation. Using β-galactosidase from C. arvensis seeds, lactose hydrolysis in milk up to approx. 50 % was observed. The findings indicate the potential use of C. arvensis seeds for the production of low/delactosed milk for lactose-intolerant population. • β-galactosidase from C. arvensis seeds was purified 24-fold with 13.2% yield. • The β-galactosidase was most active when activated by EDTA at 40 °C and pH 4. • The purified enzyme hydrolyzes milk lactose with a t 1/2 of 20 min, making it the fastest of the β-galactosidases studied. • GOS was produced by both purified β-galactosidase and sonicated cells. • Thermostable, an industrially important enzyme derived from C. arvensis seeds for industrial use. [ABSTRACT FROM AUTHOR]

[Display omitted] Besides factors such as disintegrant and lubricant, the raw material properties of filler excipients can have an impact on the disintegration behavior of a tablet. The current research aims to model the impact of lactose properties on disintegration time. For the first time, the impact of lactose polymorphism, tablet tensile strength, and pore structure parameters on disintegration were evaluated in one study. Six different lactose qualities were compacted into tablets of different solid fractions in a formulation with 5 %w/w diclofenac sodium, 1 %w/w magnesium stearate and 2 %w/w croscarmellose sodium. A linear model was built to identify which parameters impact the disintegration time, using as potential variables the polymorphic composition of the lactose, the porosity, pore size distribution and the tablet tensile strength. The model variables were derived from literature and calibrated with data. After optimization, the model shows a strong correlation (r2 = 0.982) between measured and predicted disintegration times. Among all investigated variables, the polymorphic composition of lactose, and the pore size distribution have been identified to affect tablet disintegration most. A higher concentration of lactose monohydrate in tablets leads to faster tablet disintegration, explained by the slower dissolution rate of lactose monohydrate compared to anhydrous and amorphous lactose. Tablet tensile strength was not identified as a direct driver for disintegration. Instead, the pore size distribution is a mutual driver for both tablet tensile strength and disintegration. The obtained insights provide guidance on the importance of quality attributes of filler binders for the prediction of tablet disintegration. This study can therefore be used as a starting point for quality-by-design formulation development and for the development of mechanistic models to predict tablet disintegration. [ABSTRACT FROM AUTHOR]

Several enzymes are anchored to solid supports for applications in the food industry as this process helps to increase the enzymatic stabilities, enabling their reuse in dairy food production. In this sense, lactase was anchored in a pectin-based hydrogel and composite hydrogel containing 5 and 10 wt% of eucalyptus residue for the hydrolysis of lactose in aqueous solutions and UHT milk. The anchorage capacity of lactase was greater at pH closer to neutrality, and enzymatic activity of anchored lactase was 86% greater than that determined for the free enzyme. The initial activity of lactase in UHT milk was impaired due to interactions with enzymatic cofactors. However, the anchored enzyme had greater activity in slower lactose hydrolysis reaction, and higher thermal stability. The presence of eucalyptus residue did not significantly affect the lactase anchorage capacity or enzymatic activity under the study experimental conditions. However, eucalyptus residue was important to improving the thermal and mechanical resistance of the solid support. Hydrogels containing anchored lactase were used for six successive lactose hydrolysis cycles without completely losing their enzymatic activity. Thus, pectin-based hydrogels containing eucalyptus residue are potential solid supports for lactase anchorage and lactose hydrolysis in food industries. [Display omitted] • Eucalyptus residue-co-pectin composite hydrogels were synthesized. • Eucalyptus/pectin-based hydrogels are efficient for lactase anchorage. • Efficiency of anchored lactase for lactose hydrolysis reactions. • Polymeric network and enzymatic cofactors affect the lactase performance. • Low lactase fraction released during lactose hydrolysis reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] Pulmonary drug delivery has gained great attention in local or systemic diseases therapy, however it is still difficult to scale-up DPI production due to the complexity of interactions taking place in DPI systems and limited understanding between flowability and inter-particle interactions in DPI formulations. Therefore, finding some quantitative parameters related to DPI delivery performance for predicting the in vitro drug deposition behavior is essential. Therefore, this study introduces a potential model for predicting aerodynamic performance of carrier-based DPIs, as well to find more relevant fine powder size and optimal shape to improve aerodynamic performance. Using salbutamol sulfate as a model drug, Lactohale®206 as coarse carrier, Lactohale®300, Lactohale®230, and Lactohale®210 as third fine components individually, the mixtures were prepared at 1% (w/w) drug content accompanied with carriers and the third component (ranging from 3% to 7%), influence of lactose fines size on DPI formulation's rheological and aerodynamic properties was investigated. The optimum drug particle shape was also confirmed by computer fluid dynamics model. This study proved that pulmonary deposition efficiency could be improved by decreasing lactose fines size. Only fines in the size range of 0–11 μm have a good linear relationship with FPF, attributed to the fluidization energy enhancement and aggregates mechanism. Once exceeding 11 μm, fine lactose would act as a second carrier, with increased drug adhesion. Computational fluid dynamics (CFD) models indicated fibrous drug particles were beneficial to transfer to the deep lung. Furthermore, good correlations between rheological parameters and FPF of ternary mixtures with different lactose fines were established, and it was disclosed that the FPF was more dependent on interaction parameters than that of flowability. [ABSTRACT FROM AUTHOR]

Background The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), a federal nutrition assistance program supporting low-income families, serves half of United States–born infants, most of whom are issued infant formula by age 2 mo. Obesity prevalence is high among children of low-income households, particularly formula-fed children. Objectives This study was conducted to determine whether glucose-based lactose-reduced infant formula made with corn syrup solids (CSSF) is associated with increased obesity risk compared with non-CSSFs that are lactose based. Design WIC administrative data on infant formula issuance and child weights and lengths were collected prospectively in Southern California between 2012 and 2020. Included children stopped breastfeeding by 3 mo, were issued cow's milk–based formula through 12 mo, and were enrolled through the final year of WIC eligibility at age 4 y (n  = 15,246). CSSF issuance was assessed continuously (range 0–13 mo) and dichotomously (any, none). Poisson and linear risk regression with robust SE estimates generated risk ratios (RRs), risk differences, and CIs for child obesity [BMI for age (in kg/m 2) ≥95th percentile]. Results Any CSSF was issued to 23% of children, and 25% were obese at age 4 y. Children with any CSSF issuance had 10% higher obesity risk (RR: 1.10; 95% CI: 1.02, 1.20) than children with no CSSF issuance at age 2 y. Associations remained significant through age 4 y (RR: 1.07; 95% CI: 1.01,1.14), independent of maternal weight status, total formula issued and breastfeeding duration, and were not modified by child race or sex. Obesity risk increased with additional mo of CSSF exposure, reaching 16% higher risk (RR: 1.16; 95% CI: 1.05, 1.28) at age 2 y for children with 12 mo of CSSF. Conclusions CSSF issuance is associated with increased obesity risk in the first 5 y life in a dose dependent manner, independently of maternal weight status, breastfeeding duration, and total formula issuance. [ABSTRACT FROM AUTHOR]

Galactooligosaccharides are composed mainly of galactosyl lactose, which is important for infant growth and as a functional food additive. Although galactosyl lactose is abundant in goat milk, its complex structure has hindered the separation and analysis of its isomers. In this study, 5 isomers of goat milk galactosyl lactose were separated by HPLC: β6′-galactosyl lactose (β6′-GL), α6′-galactosyl lactose (α6′-GL), β4′-galactosyl lactose (β4′-GL), α3′-galactosyl lactose (α3′-GL), and β3′-galactosyl lactose (β3′-GL). This composition differs from that of commercial galactooligosaccharide products, which comprise mainly β-configuration oligosaccharides. The isomers were then qualitatively and quantitatively compared at different lactation stages using online HPLC-mass spectrometry. Relative quantitative analysis showed that the total content of the 5 galactosyl lactose isomers was highest in transitional goat milk. Specifically, β3′-GL was the main isomer in colostrum and α3′-GL was the main isomer in transitional and mature milk. β6′-Galactosyl lactose and β4′-GL tended to increase and then decrease during lactation. Moreover, α3′-GL content was 2 times higher than in colostrum and 10 times higher in transitional milk than in mature milk; in contrast, for β3′-GL, the values were 5 and 2 times higher, respectively. Absolute quantitative analysis revealed that β3′-GL was the most abundant isomers in colostrum (32.3 mg/L), and α3′-GL was the most abundant in transitional milk (88.1 mg/L) and mature milk (36.3 mg/L). These findings provide an important quantitative basis for understanding the relationship between structure and function of galactosyl lactose in goat milk, as well as its exploitation as a functional food. [ABSTRACT FROM AUTHOR]

β-Galactosidase (lacA) from Aspergillus oryzae is widely used in the dairy industry. Its acidic pH optimum and severe product inhibition limit its application for lactose hydrolysis in milk. In the present study, structure-based sequence alignment was conducted to determine the candidate mutations to shift the pH optimum of lacA to the neutral range. The Y138F and Y364F mutants shifted the pH optimum of lacA from 4.5 to 5.5 and 6.0, respectively. The acid dissociation constant (p K a) values of catalytic acid/base residues with upwards shift were consistent with the increased pH optimum. All variants in the present study also alleviated galactose inhibition to various extents. Molecular dynamics demonstrated that the less rigid tertiary structures and lower galactose-binding free energy of Y138F and Y364F might facilitate the release of the end product. Both Y138F and Y364F mutants exhibited better hydrolytic ability than lacA in milk lactose hydrolysis. The higher pH optimum and lower galactose inhibition of Y138F and Y364F may explain their superiority over lacA. The Y138F and Y364F mutants in the present study showed potential in producing low-lactose milk, and our studies provide a novel strategy for engineering the pH optimum of glycoside hydrolase. [ABSTRACT FROM AUTHOR]