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Summary: In this work, the antihypertensive and antithrombotic activities of milk fermented with Lacticaseibacillus rhamnosus GG and Lactobacillus delbrueckii ssp. Bulgaricus NCFB 2772 (monoculture and co‐culture), were studied. It was observed that both species, as well as the co‐culture, showed an increase in proteolytic activity during fermentation, which is related to the increase in the biological activities studied. Both biological activities increased as a function of fermentation time, describing a curve similar to that of their proteolytic activity, which could indicate the release of bioactive peptides due to the proteolytic activity of the bacteria. The highest antihypertensive activity was obtained at 12 h of fermentation and was 74.9% for Lb. rhamnosus, 79.1% for L. delbrueckii and 77.6% for the co‐culture, with no significant difference between these values. On the other hand, the antithrombotic activity was 56.1% for Lb. rhamnosus, 49.9% for L. delbrueckii and 72.3% for the co‐culture. These findings contribute to the knowledge about the influence of fermentation conditions on biological activity of fermented milk, while emphasising the additional benefits of probiotic and industrially important lactic acid bacteria. [ABSTRACT FROM AUTHOR]

The probiotic Lactiplantibacillus plantarum could not independently ferment milk to form yoghurt. In this study, the effect of Streptococcus thermophilus extract on the acidification and propagation capabilities of L. plantarum during milk fermentation was investigated. The results showed that the addition of S. thermophilus crude cell extract significantly shortened the fermentation time and promoted the propagation of L. plantarum. Moreover, the addition of 0.2% S. thermophilus cell extract resulted in a higher acidification rate (final pH: 4.53) at 72 h of fermentation and a higher L. plantarum cell count (log 8.31 cfu/g) at 24 h of fermentation at 37°C. It was speculated that the presence of amino acids and free nucleotides in S. thermophilus lysate might have played an indispensable role during milk fermentation by L. plantarum. This study provided a novel strategy for utilising L. plantarum to ferment milk without using exogenous food ingredients. [ABSTRACT FROM AUTHOR]

ABSTRACT: Milk-derived peptides have emerged as a popular mean to manage various lifestyle disorders such as diabetes. Fermentation is being explored as one of the faster and efficient way of producing peptides with antidiabetic potential. Therefore, in this study, an attempt was made to comparatively investigate the pancreatic α-amylase (PAA) inhibitory properties of peptides derived from milk of different farm animals through probiotic fermentation. Peptide's identification was carried out using liquid chromatography-quadrupole time-of-flight mass spectrometry and inhibition mechanisms were characterized by molecular docking. Results obtained showed a PAA-IC50 value (the amount of protein equivalent needed to inhibit 50% of enzymes) between 2.39 and 36.1 µg protein equivalent for different fermented samples. Overall, Pediococcus pentosaceus MF000957-derived fermented milk from all animals indicated higher PAA inhibition than other probiotic derived fermented milk (PAA-IC50 values of 6.01, 3.53, 15.6, and 10.8 µg protein equivalent for bovine, camel, goat, and sheep fermented milk). Further, molecular docking analysis indicated that camel milk-derived peptide IMEQQQTEDEQQDK and goat milk-derived peptide DQHQKAMKPWTQPK were the most potent PAA inhibitory peptides. Overall, the study concluded that fermentation derived peptides may prove useful in for managing diabetes via inhibition of carbohydrate digesting enzyme PAA.

Milk-derived peptides have emerged as a popular mean to manage various lifestyle disorders such as diabetes. Fermentation is being explored as one of the faster and efficient way of producing peptides with antidiabetic potential. Therefore, in this study, an attempt was made to comparatively investigate the pancreatic α-amylase (PAA) inhibitory properties of peptides derived from milk of different farm animals through probiotic fermentation. Peptide's identification was carried out using liquid chromatography-quadrupole time-of-flight mass spectrometry and inhibition mechanisms were characterized by molecular docking. Results obtained showed a PAA-IC 50 value (the amount of protein equivalent needed to inhibit 50% of enzymes) between 2.39 and 36.1 µg protein equivalent for different fermented samples. Overall, Pediococcus pentosaceus MF000957-derived fermented milk from all animals indicated higher PAA inhibition than other probiotic derived fermented milk (PAA-IC 50 values of 6.01, 3.53, 15.6, and 10.8 µg protein equivalent for bovine, camel, goat, and sheep fermented milk). Further, molecular docking analysis indicated that camel milk-derived peptide IMEQQQTEDEQQDK and goat milk-derived peptide DQHQKAMKPWTQPK were the most potent PAA inhibitory peptides. Overall, the study concluded that fermentation derived peptides may prove useful in for managing diabetes via inhibition of carbohydrate digesting enzyme PAA. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: The cultures used in the production of "bio-yoghurts" typically consist of a blend of traditional yogurt starters, such as S. thermophilus and L. delbrueckii subsp. bulgaricus, along with probiotics like L. acidophilus, L. casei, L. reuteri, and Bifidobacterium spp. These probiotics, although beneficial, face challenges thriving in milk due to its short fermentation time (4-5 hours). The rapid acidification caused by the starter's results in probiotic levels dropping below the "therapeutic minimum" during the intended refrigerated shelf life of the product. A potential solution to this issue lies in leveraging lactic acid bacteria isolated from the human milk which possess both robust probiotic characteristics and starter properties. Incorporating such strains in yogurt starter could address the acidity imbalance and contribute to maintaining optimal probiotic levels throughout the refrigerated shelf life of the product. Objective: This research aims to develop a new generation of sustainable functional yoghurts suitable for consumers of all ages using as starters predominant probiotic lactic acid bacteria isolated from the breast milk of healthy women. Results: This study marks the first implementation of the critical dilution culture method in sterile cow milk for the selection of predominant lactic acid bacteria (LABs) from women's breast milk. Remarkably, all samples yielded LAB capable of independently fermenting milk. Although breast milk is a good medium for the growth of residential lactic acid bacteria, it never coagulates due to low concentration of caseins. The isolated strains, identified as belonging to the species L. delbrueckii subsp. lactis, L. fermentum, L. casei subsp. sakei, Streptococcus thermophiles and Lactococcus lactis, exhibited probiotic and adaptive properties essential for gut colonization in humans. Utilizing symbiotic LAB starters were created functional yogurts with heightened technological, physicochemical, and sensory characteristics. Conclusions: Yogurts fermented using human milk LABs are safe and can be recommended as a functional dairy food, for pregnant women as well as for pre-term and full-term infants as a substitute/supplement for mother's milk. Moreover, these LABs can be included in infant formulas or used in pre-treatment of infant formula milk to improve its nutritional value and safety. [ABSTRACT FROM AUTHOR]

Gamma-aminobutyric acid (GABA)-producing lactic acid bacteria (LAB) can be used as starters in the development of GABA-enriched functional fermented foods. In this work, four GABA-producing strains each of Lactococcus lactis and Streptococcus thermophilus species were isolated from cow's milk, and their phenotypic, technological, and safety profiles determined. Genome analysis provided genetic support for the majority of the analyzed traits, namely, GABA production, growth in milk, and the absence of genes of concern. The operon harboring the glutamate decarboxylase gene (gadB) was chromosomally encoded in all strains and showed the same gene content and gene order as those reported, respectively, for L. lactis and S. thermophilus. In the latter species, the operon was flanked (as in most strains of this species) by complete or truncated copies of insertion sequences (IS), suggesting recent acquisition through horizontal gene transfer. The genomes of three L. lactis and two S. thermophilus strains showed a gene encoding a caseinolytic proteinase (PrtP in L. lactis and PrtS in S. thermophilus). Of these, all but one grew in milk, forming a coagulum of good appearance and an appealing acidic flavor and taste. They also produced GABA in milk supplemented with monosodium glutamate. Two L. lactis strains were identified as belonging to the biovar. diacetylactis, utilized citrate from milk, and produced significant amounts of acetoin. None of the strains showed any noticeable antibiotic resistance, nor did their genomes harbor transferable antibiotic resistance genes or genes involved in toxicity, virulence, or pathogenicity. Altogether these results suggest that all eight strains may be considered candidates for use as starters or components of mixed LAB cultures for the manufacture of GABA-enriched fermented dairy products. [ABSTRACT FROM AUTHOR]

Enterococci, known for their resilience, are commonly found in food, the environment, and the gastrointestinal tracts of humans and animals. In recent research, six strains of enterococcus were isolated from bat guano. These include Enterococcus mundtii SRBG1, Enterococcus gallinarum SRBG3, Enterococcus faecium SRBG2, Enterococcus casseliflavus EC1, and Enterococcus devriesei CAU 1344. Identification was done using 16S DNA analysis. Each strain underwent evaluation for its technological properties (such as tolerances to various NaCl concentrations and temperatures, as well as amylolytic, β-galactosidase, lipolytic, and proteolytic activities, and EPS production) and selected probiotic properties (including safety profile, resistance to 0.3 percent bile salts and gastric juice with a pH of 2.5, lysozyme tolerance, and antibacterial and antibiofilm activities against four foodborne pathogens). The results were analyzed using Principal Component Analysis. This analysis revealed that E. mundtii SRBG1 and E. gallinarum SRBG3, followed by E. faecium SRBG2, were most closely associated with a broad range of technological characteristics and were subsequently used for fermenting skimmed milk. The rheological properties of the samples indicated a shear-thinning or non-Newtonian behavior. Furthermore, during storage of the fermented milk at 4 °C over periods of 1, 7, 14, and 21 days, there were no significant changes in bacterial count (at around 7 log10 CFU/mL) and pH when fermented with the three evaluated strains. [ABSTRACT FROM AUTHOR]

The objective of this research was to explore the functional qualities of two EPSs produced by recently discovered LAB (Lactobacillus delbrueckii (EPS-LB3) and Lacticaseibacillus rhamnosus (EPS-MLB3)) that have potential probiotic benefits. The study involved evaluating their biological characteristics, such as their antioxidant, antidiabetic, antimicrobial, antibiofilm, and antiproliferative activities at various concentrations, as well as investigating their effects on the gut microbiome through in vitro fecal fermentation. Moreover, the study analyzed the rheological properties of the EPSs in fermented bovine milk. The average molecular weights of the extracted EPS were 3762.43 kDa and 1272.19 kDa with monosaccharide compositions of Glu:Rib:Man:Xyl (1.0:16.4:6.6:6.5) and Rib:Man:Xyl:GA:Ara (7.1:1.6:4.8:1.0:9.0) for EPS-LB3 and EPS-MLB3, respectively. EPS-LB3 and EPS-MLB3 at 250 mg/L showed scavenging rates of 34.0 ± 1.7 % and 37.5 ± 1.1 % for DPPH, 47.3 ± 0.8 % and 56.6 ± 0.7 % for ABTS, 38.3 ± 0.5 % and 43.5 ± 0.6 % for SD, 53.9 ± 0.1 % and 54.7 ± 0.1 % for SAS, 10.6 ± 0.1 % and 10.7 ± 0.2 % for HP, 88.8 ± 0.1 % and 84.8 ± 0.5 % for HRS, 80.0 ± 1.4 % and 84.5 ± 0.8 % for MC, as well as 60.6 ± 1.7 % and 58.1 ± 0.9 % for Lipid Oxidation, respectively, suggesting good antioxidant properties. They also exhibited antimicrobial and anti-biofilm effects against several foodborne pathogens, and antiproliferative activities against cancer cell lines. Additionally, the utilization of EPS by several probiotics indicated the prebiotic nature of EPS. The effect of both EPS on gut microbiome by fecal fermentation revealed that these EPS promoted selective bacteria like Faecalibacterium prausnitzii and Ruminococcus bromii in the gut, which are responsible for carbohydrate metabolism and short-chain fatty acid production.

The responses of various microbial populations to modifications in the physicochemical properties of a food matrix, as well as interactions between these populations already present, are the main factors that shape microbial dynamics in that matrix. This work focused on the study of microbial dynamics during labneh Ambaris production, a traditional Lebanese concentrated fermented goat milk made in jars during 3 months. This was assessed in two earthenware jars at a production facility. DNA metabarcoding of the ITS2 region as well as the V3–V4 region of the 16S rRNA gene was used to characterize the fungal and bacterial communities, respectively. Viable bacterial isolates were also identified by Sanger sequencing of the V1–V4 region of the 16S rRNA gene. Our results showed that the dominant microorganisms identified within labneh Ambaris (Lactobacillus kefiranofaciens, Lentilactobacillus kefiri, Lactococcus lactis, Geotrichum candidum, Pichia kudriavzevii and Starmerella sp.) settle early in the product and remain until the end of maturation with varying abundances throughout fermentation. Microbial counts increased during early fermentation stage, and remained stable during mid-fermentation, then declined during maturation. While microbial compositions were globally comparable between the two jars during mid-fermentation and maturation stages, differences between the two jars were mainly detected during early fermentation stage (D0 until D10). No significant sensorial differences were observed between the final products made in the two jars. Neither coliforms nor Enterobacteriaceae were detected in their viable state, starting D7 in both jars, suggesting the antimicrobial properties of the product. [ABSTRACT FROM AUTHOR]

Enterococci, known for their resilience, are commonly found in food, the environment, and the gastrointestinal tracts of humans and animals. In recent research, six strains of enterococcus were isolated from bat guano. These include Enterococcus mundtii SRBG1, Enterococcus gallinarum SRBG3, Enterococcus faecium SRBG2, Enterococcus casseliflavus EC1, and Enterococcus devriesei CAU 1344. Identification was done using 16S DNA analysis. Each strain underwent evaluation for its technological properties (such as tolerances to various NaCl concentrations and temperatures, as well as amylolytic, β-galactosidase, lipolytic, and proteolytic activities, and EPS production) and selected probiotic properties (including safety profile, resistance to 0.3 percent bile salts and gastric juice with a pH of 2.5, lysozyme tolerance, and antibacterial and antibiofilm activities against four foodborne pathogens). The results were analyzed using Principal Component Analysis. This analysis revealed that E. mundtii SRBG1 and E. gallinarum SRBG3, followed by E. faecium SRBG2, were most closely associated with a broad range of technological characteristics and were subsequently used for fermenting skimmed milk. The rheological properties of the samples indicated a shear-thinning or non-Newtonian behavior. Furthermore, during storage of the fermented milk at 4 °C over periods of 1, 7, 14, and 21 days, there were no significant changes in bacterial count (at around 7 log10 CFU/mL) and pH when fermented with the three evaluated strains.

Lacticaseibacillus paracasei (formerly Lactobacillus paracasei) is a nomadic lactic acid bacterium (LAB) that inhabits a wide variety of ecological niches, from fermented foodstuffs to host-associated microenvironments. Many of the isolated L. paracasei strains have been used as single-strain probiotics or as part of a symbiotic consortium within formulations. The present study contributes to the exploration of different strains of L. paracasei derived from non-conventional isolation sources—the South African traditional fermented drink mahewu (strains MA2 and MA3) and kefir grains (strains KF1 and ABK). The performed microbiological, biochemical and genomic comparative analyses of the studied strains demonstrated correlation between properties of the strains and their isolation source, which suggests the presence of at least partial strain adaptation to the isolation environments. Additionally, for the studied strains, antagonistic activities against common pathogens and against each other were observed, and the ability to release bioactive peptides with antioxidant and angiotensin I-converting enzyme inhibitory (ACE-I) properties during milk fermentation was investigated. The obtained results may be useful for a deeper understanding of the nomadic lifestyle of L. paracasei and for the development of new starter cultures and probiotic preparations based on this LAB in the future. [ABSTRACT FROM AUTHOR]

This study evaluated the ability of two strains of bacterial starter cultures, Lactobacillus casei AP (AP) and Lactobacillus casei AG (AG), to produce exopolysaccharides (EPSs). First, the physicochemical properties of the fermented milk produced by AP and AG were assessed, including physical qualities like viscosity and syneresis and chemical qualities, such as pH, acidity, protein, lactose, fat content, and total solid. Then, AP and AG's ability to produce EPS was measured. Additionally, the EPS' microstructure was observed using a scanning electron microscope, and its chemical structure was assessed using Fourier transform-infrared (FT-IR) spectroscopy. Also, AP and AG's ability to produce EPS was tracked at the molecular level by studying the glycosyltransferase (gtf) gene. Statistical analysis showed that the milk fermented using AP and AG had similar physicochemical qualities (P > 0.05) but significantly different physical qualities (P < 0.05). Additionally, the milk fermented with AP had lower viscosity (1137.33 ± 34.31 centiPoise) than AG (1221.50 ± 20.66 centiPoise). In addition, the milk fermented using AP had higher syneresis (19.42%) than AG (17.83%). The higher viscosity and lower syneresis in the milk fermented using AG were associated with AG's ability to produce more EPS (1409 mg/L) than AP (1204 mg/L). In addition, according to the FT-IR analysis, the AP- and AG-synthesized EPS contained absorption bands at 3323, 2980, 2901, 1642, 1084, 1043, and 873 cm−1. The absorption band at 1642 and 2980 cm−1 corresponds to carbonyl and methylene groups, respectively. Absorption band 873 cm−1 is characteristic of the α-glycosidic bond of α-glucan in EPS. Moreover, the absorption bands on the wavelength region corresponding to the functional groups in the AP- and AG-produced EPS were similar to those in commercially available EPS. Lastly, gtf, contributing to EPS synthesis, was found in the genomes of AP and AG, suggesting the role of glycosyltransferase in the EPS synthesis by both strains.

In the current research, Enterococcus mundtii SRBG1 newly isolated from Bat guano was encapsulated using spray drying technique to create a probiotic powder using six combinations of inulin, maltodextrin and sodium alginate. The encapsulation yield, moisture content, physical characteristics, and shape were investigated. Microcapsules yields ranged from 67 to 85 percent, which is consistent with typical B-290 spray-drier yields. The moisture content showed to increase (4 ± 0.15%) with the addition of sodium alginate to inulin and maltodextrin. In the gastrointestinal conditions (simulated gastric juice and bile salts), it was shown that the viability of probiotic cells in capsules was higher than that of free cells. This demonstrated the effectiveness of combining inulin and maltodextrin to encapsulate substances in surviving in gastro-intestinal conditions. Additionally, we evaluated the non-encapsulated and encapsulated SRBG1 by assessing their impact on the rheological parameters of fermented milk. The results showed that in the absence of sodium alginate the viscosity of milk was lower than with the other protectors, which was confirmed by the quick acidification of the fermented milk by microcapsules containing sodium alginate.

Currently, functional dairy products pave a promising way for the prophylaxis of essential hypertension, and the search for new strains capable of producing such products is a constant challenge for scientists around the world. In this study, the antihypertensive properties of milk fermented with several strains of traditional yogurt starters (Lactobacillus delbrueckii strains Lb100 and Lb200; Lactococcus lactis strains dlA, AM1 and MA1; Streptococcus thermophilus strains 159 and 16t) and one strain of non-conventional probiotic starter (Lacticaseibacillus paracasei ABK) were assessed. The in vitro assessment using angiotensin-converting enzyme inhibition assay was performed for all fermentation products, and the best performed products were tested in vivo using Spontaneously Hypertensive Rat (SHR) animal model. In addition, for the best performed products the fatty acid (FA) composition and FA-related nutritional indices were determined. As a result, the milk fermented with two strains (Lb. delbrueckii LB100 and Lc. lactis AM1) demonstrated significant antihypertensive effect during both in vitro and in vivo experiments. Moreover, the milk fermented with Lb. delbrueckii Lb100 demonstrated significantly better FA-related nutritional indexes and lowered total cholesterol in SHRs upon regular consumption. The obtained results can be used in the future to develop new starter cultures producing effective functional antihypertensive dairy products. [ABSTRACT FROM AUTHOR]

Milk kefir fermentation has been used in households for generations. Consumption of milk kefir has been associated with various health benefits, presumably from the probiotics of yeast and bacteria that make up the kefir grains. In addition, many of the microbes are known to produce novel antimicrobial compounds that can be used for other applications. The microbes living inside kefir grains differ significantly depending on geographical location and production methods. In this study, we aimed to use metagenomic analysis of fermented milk by using three different kefir grains (kefir 1, kefir 2, and kefir 3) from different US sources. We analyzed the microbial compositions of the three milk fermentation samples. This study revealed that each sample contains unique and distinct groups of microbes, kefir 1 showed the least diversity, and kefir 3 showed the highest diversity. Kefir 3 is rich in Proteobacteria while kefir 2 is dominated by the Firmicutes. Using bacterial indicator growth analyses carried out by continuous readings from microplate-based bioreactor assays suggested that kefir 2 fermentation filtrate has higher antibacterial property. We have screened 30 purified cultures of kefir 2 sample and isolated two lactic acid bacteria strains with higher antibacterial activities; the two strains were identified as Leuconostoc mesenteroides 28–1 and Lentilactobacillus kefiri 25–2 by 16S genomic PCR with confirmed antibacterial activities of fermentation filtrate after growing under both aerobic and anaerobic conditions. [ABSTRACT FROM AUTHOR]

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The responses of various microbial populations to modifications in the physicochemical properties of a food matrix, as well as interactions between these populations already present, are the main factors that shape microbial dynamics in that matrix. This work focused on the study of microbial dynamics during labneh Ambaris production, a traditional Lebanese concentrated fermented goat milk made in jars during 3 months. This was assessed in two earthenware jars at a production facility. DNA metabarcoding of the ITS2 region as well as the V3–V4 region of the 16S rRNA gene was used to characterize the fungal and bacterial communities, respectively. Viable bacterial isolates were also identified by Sanger sequencing of the V1–V4 region of the 16S rRNA gene. Our results showed that the dominant microorganisms identified within labneh Ambaris (Lactobacillus kefiranofaciens, Lentilactobacillus kefiri, Lactococcus lactis, Geotrichum candidum, Pichia kudriavzevii and Starmerella sp.) settle early in the product and remain until the end of maturation with varying abundances throughout fermentation. Microbial counts increased during early fermentation stage, and remained stable during mid-fermentation, then declined during maturation. While microbial compositions were globally comparable between the two jars during mid-fermentation and maturation stages, differences between the two jars were mainly detected during early fermentation stage (D0 until D10). No significant sensorial differences were observed between the final products made in the two jars. Neither coliforms nor Enterobacteriaceae were detected in their viable state, starting D7 in both jars, suggesting the antimicrobial properties of the product.

Abstract Bacteriophages infecting dairy starter bacteria are a leading cause of milk fermentation failure and strategies to reduce the risk of phage infection in dairy settings are demanded. Along with dairy starters, bacteriocin producers (protective cultures) or the direct addition of bacteriocins as biopreservatives may be applied in food to extend shelf‐life. In this work, we have studied the progress of infection of Lactococcus cremoris MG1363 by the phage sk1, in the presence of three bacteriocins with different modes of action: nisin, lactococcin A (LcnA), and lactococcin 972 (Lcn972). We aimed to reveal putative bacteriocin‐phage interactions (BaPI) that could be detrimental and increase the risk of fermentation failure due to phages. Based on infections in broth and solid media, a synergistic effect was observed with Lcn972. This positive sk1‐Lcn972 interaction could be correlated with an increased burst size. sk1‐Lcn972 BaPI occurred independently of a functional SOS and cell envelope stress response but was lost in the absence of the major autolysin AcmA. Furthermore, BaPI was not exclusive to the sk1‐Lcn972 pairing and could be observed with other phages and lactococcal strains. Therefore, bacteriocins may facilitate phage predation of dairy lactococci and their use should be carefully evaluated.

This study evaluated the ability of two strains of bacterial starter cultures, Lactobacillus casei AP (AP) and Lactobacillus casei AG (AG), to produce exopolysaccharides (EPSs). First, the physicochemical properties of the fermented milk produced by AP and AG were assessed, including physical qualities like viscosity and syneresis and chemical qualities, such as pH, acidity, protein, lactose, fat content, and total solid. Then, AP and AG's ability to produce EPS was measured. Additionally, the EPS' microstructure was observed using a scanning electron microscope, and its chemical structure was assessed using Fourier transform-infrared (FT-IR) spectroscopy. Also, AP and AG's ability to produce EPS was tracked at the molecular level by studying the glycosyltransferase (gtf) gene. Statistical analysis showed that the milk fermented using AP and AG had similar physicochemical qualities (P > 0.05) but significantly different physical qualities (P < 0.05). Additionally, the milk fermented with AP had lower viscosity (1137.33 ± 34.31 centiPoise) than AG (1221.50 ± 20.66 centiPoise). In addition, the milk fermented using AP had higher syneresis (19.42%) than AG (17.83%). The higher viscosity and lower syneresis in the milk fermented using AG were associated with AG's ability to produce more EPS (1409 mg/L) than AP (1204 mg/L). In addition, according to the FT-IR analysis, the AP- and AG-synthesized EPS contained absorption bands at 3323, 2980, 2901, 1642, 1084, 1043, and 873 cm-1. The absorption band at 1642 and 2980 cm-1 corresponds to carbonyl and methylene groups, respectively. Absorption band 873 cm-1 is characteristic of the a-glycosidic bond of a-glucan in EPS. Moreover, the absorption bands on the wavelength region corresponding to the functional groups in the AP- and AG-produced EPS were similar to those in commercially available EPS. Lastly, gtf, contributing to EPS synthesis, was found in the genomes of AP and AG, suggesting the role of glycosyltransferase in the EPS synthesis by both strains. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate and comparethe probiotic propertiesofLactobacillus helveticusNK1, Lactobacillus rhamnosusF and Lactobacillus reuteriLR1lactobacilli strains. Changes in pH, cell growth, proteolytic activity, antioxidantactivity, and angiotensin-converting enzyme(ACE)inhibitoryactivity were monitored during fermentation of reconstituted skim milk (RSM) by pure cultures of lactobacilli. Among the tested strains, L. helveticusNK1 showed the highest proteolytic, ACE inhibitoryand antioxidantactivitiesduring milk fermentation, followed by L. rhamnosus F and L. reuteriLR1. The promising capability of all of the lactobacilli strains to release bioactivepeptides from the milk proteins was demonstrated. [ABSTRACT FROM AUTHOR]

ABSTRAK. Penelitian ini bertujuan mengetahui peningkatan kualitas produk susu fermentasi dengan menggunakan khamir Kluyveromyces lactis dan penambahan jagung manis. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) pola faktorial yang terdiri dari 2 faktor dan 2 level, yaitu faktor penambahan jagung manis (Zea mays saccharata Linn) (A) terdiri atas 25% (a1) dan 75% (a2), dan faktor penambahan khamir Kluyveromyces lactis (B) terdiri atas 0.5% (b1) dan 1% (b2), dengan lima kali ulangan pada masing-masing perlakuan sehingga memperoleh 20 satuan percobaan. Parameter yang diamati antara lain adalah kadar protein, kadar lemak, kadar asam laktat dan derajat keasaman (pH). Data yang diperoleh dianalisis secara statistik menggunakan ANOVA dan dilanjutkan dengan uji lanjut Duncan. Hasil penelitian menunjukkan bahwa penambahan khamir Kluyveromyces lactis tidak berpengaruh nyata (P0.05) terhadap kadar protein, lemak, kadar asam laktat dan derajat keasaman (pH). Sementara penambahan jagung manis tidak berpengaruh nyata (P0.05) terhadap kadar protein dan derajat keasaman (pH), namun berpengaruh sangat nyata (P0.01) terhadap kadar lemak dan kadar asam laktat. Berdasarkan hasil penelitian dapat disimpulkan bahwa penambahan khamir Kluyveromyces lactis 1% dan jagung manis (Zea mays saccharata Linn) 75% pada produk susu fermentasi dapat meningkatkan kualitas produk susu. (Potential of yeast-Kluyveromyces lactis in improving quality of fermented milk added sweet corn (Zea mays saccharata Linn)) ABSTRACT. The aims of this research were to determine the quality improvement of fermented milk products using Kluyveromyces lactis and the addition of sweet corn. This study used factorial experiment conducted with completely randomized design (CRD) which divide into 2 factors and 2 levels, there were the addition of sweet corn (Zea mays saccharata Linn) factors (A) consist of 25% (a1) and 75% (a2), and the addition of yeast Kluyveromyces lactis factors (B) consist of 0.5% (b1) and 1% (b2), with five replications on each treatment to obtain 20 units of experiment. The observed parameters such as protein levels, fat levels, lactic acid levels and acidity degree (pH). Research data were analyzed statistically by using ANOVA and continued by Duncan's tests. The results showed that the addition of yeast Kluyveromyces lactis had no significant effect (P 0.05) on protein levels, fat levels, lactic acid levels and acidity degree (pH). While the addition of sweet corn had no significant effect (P 0.05) on protein levels and acidity degree (pH), but it had a very significant effects (P 0.01) on fat levels and lactic acid levels. The results indicate the addition of yeast Kluyveromyces lactis 1% and sweet corn (Zea mays saccharata Linn) 75% in fermented milk products can improve the quality of dairy products.

Hypercholesterolemia is a disease that is indicated by the increasing level of cholesterol in the body and also as one of the factors causing cardiovascular disease. An alternative that can be done to prevent hypercholesterolemia is by consuming fermented milk. Skim milk is fermented using probiotic of Lactobacillus acidophillus, Lactobacillus plantarum and Streptococcus thermophilus. The skimmed milk that has been fermented is then tested for total lactic acid bacteria, total acid, pH, and in vivo analysis for antihypercholesterolemia activity using animal model. In this study, the animal models used were male white rats which were grouped into three treatment groups, namely negative control, positive control, and fermented milk group. The result of the study shows that the total lactic acid bacteria, total acid and pH of fermented skim milk were 5.25 x109 CFU/ml; 2.190% and pH 4.06, respectively. From the results, fermented milk with probiotics has the ability to reduce cholesterol levels in the blood of male white rats effectively in vivo.

We analysed the correlations of milk fermentability (yogurt test acidity), renneting (time to rennet coagulation of milk protein) and results of ethanol tests (indirect indicator of milk thermostability) with the percentages of the milk components. The correlations of the milk component percentages with renneting were mostly weak, while the correlations with the ethanol test were even poorer. The CSN3 and LGB genotypes did not show a significant interaction in their influence on milk fermentability, renneting or ethanol test results. For the ethanol test, many significant interactions were observed between the DGAT1, LEP, FASN, SCD1, CSN2, CSN3 and LGB genotypes. DGAT1 interacted significantly with all genes for milk fermentability. For renneting that was measured instrumentally, CSN3 interacted significantly with DGAT1, FASN, SCD1, CSN2 A/B, CSN2 A1/A2; SCD1 interacted significantly with LEP and FASN. The breed and genotypes did not show any interactions. Farm and genotypes interacted significantly for all the technological properties studied; similar results were observed for the protein percentage and the genotypes, except that no interactions influenced the ethanol test results.

This study was carried out to investigate the contribution of two strains of Lactobacilli; Lactobacillus casei 431 and Lactobacillus acidophilus La-5 to the volatile organic compounds (VOCs) in fermented milk. The samples were subjected to the headspace-solid phase micro-extraction (HS-SPME) and gas chromatography mass spectrometry (GC-MS). Prior to the HS-SPME, four different silica fibres were screened for their ability to retain VOCs in the fermented milk. The fibre that retained the highest amount of VOCs was selected and used for the subsequent analyses. A total of 105 compounds made up of a wide range of VOCs such as acids, alcohols, aldehydes, aromatic compounds, esters and ketones were identified. The ketones were the most abundant group of compounds produced by the two strains of lactic acid bacteria (LAB) investigated. In addition, L. casei 431 was able to produce higher concentrations of typical flavour compounds like 2,3-butanedione, 2-heptanone, acetoin and 2-nonanone compared to L acidophilus La-5. As such, the ability of these strains to produce these distinct typical flavour compounds suggests their potential as starter cultures for the production of fermented dairy products with enhanced flavour/or aroma.

Lacticaseibacillus paracasei (formerly Lactobacillus paracasei) is a nomadic lactic acid bacterium (LAB) that inhabits a wide variety of ecological niches, from fermented foodstuffs to host-associated microenvironments. Many of the isolated L. paracasei strains have been used as single-strain probiotics or as part of a symbiotic consortium within formulations. The present study contributes to the exploration of different strains of L. paracasei derived from non-conventional isolation sources—the South African traditional fermented drink mahewu (strains MA2 and MA3) and kefir grains (strains KF1 and ABK). The performed microbiological, biochemical and genomic comparative analyses of the studied strains demonstrated correlation between properties of the strains and their isolation source, which suggests the presence of at least partial strain adaptation to the isolation environments. Additionally, for the studied strains, antagonistic activities against common pathogens and against each other were observed, and the ability to release bioactive peptides with antioxidant and angiotensin I-converting enzyme inhibitory (ACE-I) properties during milk fermentation was investigated. The obtained results may be useful for a deeper understanding of the nomadic lifestyle of L. paracasei and for the development of new starter cultures and probiotic preparations based on this LAB in the future.

The enzymatic repertoire of starter cultures belonging to the Lactococcus genus determines various important characteristics of fermented dairy products but might change in response to the substantial environmental changes in the manufacturing process. Assessing bacterial proteome adaptation in dairy and other food environments is challenging due to the high matrix-protein concentration and is even further complicated in particularly cheese by the high fat concentrations, the semi-solid state of that matrix, and the non-growing state of the bacteria. Here, we present bacterial harvesting and processing procedures that enable reproducible, high-resolution proteome determination in lactococcal cultures harvested from laboratory media, milk, and miniature Gouda cheese. Comparative proteome analysis of Lactococcus cremoris NCDO712 grown in laboratory medium and milk revealed proteome adaptations that predominantly reflect the differential (micro-)nutrient availability in these two environments. Additionally, the drastic environmental changes during cheese manufacturing only elicited subtle changes in the L. cremoris NCDO712 proteome, including modified expression levels of enzymes involved in flavour formation. The technical advances we describe offer novel opportunities to evaluate bacterial proteomes in relation to their performance in complex, protein- and/or fat-rich food matrices and highlight the potential of steering starter culture performance by preculture condition adjustments., Competing Interests: Declaration of competing interest The project is organized by and executed under the auspices of TiFN, a public - private partnership on precompetitive research in food and nutrition. HB is part-time employed by NIZO Food Research. The authors have declared that no competing interests exist in the writing of this publication., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

[Display omitted] • Bacterial genera dominated the milk fermentation of Kazak artisanal cheese. • The correlation of microbiota was constructed in milk fermentation of Kazak artisanal cheese. • The key microbiota was identified in the milk fermentation of Kazak artisanal cheese. • The bacterial function in milk fermentation of Kazak artisanal cheese was predicted. Kazak artisanal cheese is a traditionally fermented food from the Uighur Autonomy Region of Xinjiang, China. In this study, we used Illumina MiSeq high-throughput sequencing technology to explore the microbial diversity during the milk fermentation of Kazak traditional hand-fermented cheese in Xinjiang, by analyzing the V3–V4 variable region of the bacterial 16S rRNA gene. Results showed that Lactobacillus and Lactococcus from the Firmicutes group comprised the dominant genera. Lactobacillus , Lactococcus , Acinetobacter , Anoxybacillus , Macrococcus , Acetobacter , Kurthia , Lelliottia , and Leuconostoc were identified as the key microbial groups during the milk fermentation of cheese. Correlation analysis also indicated that Lactobacillus had strong negative connections with Lactococcus , Acinetobacter , Macrococcus , Anoxybacillus, and Staphylococcus. The genera of Lactobacillus and Lactococcus (e.g., Lactobacillus paracasei B1, Lactobacillus sp. B4 and Lactococcus lactis B11) had higher enzyme activity characteristics according to the enzyme activity experiments. Subsequent gene function prediction indicated that the microorganisms in fermented milk products mainly contributed to carbohydrate and amino acid metabolism, which might be closely related to the development of the flavor of the cheese. Our study provides a theoretical basis for understanding the succession of bacteria and the application of potential functional microorganisms in Kazak cheese. [ABSTRACT FROM AUTHOR]

The problem of food safety caused by Bacillus cereus contamination has been widely concerned, particularly in milk and its products, while effective prevention and control measures have not been implemented. Reuterin is a special broad-spectrum antibacterial substance produced by Limosilactobacillus reuteri via glycerol fermentation and is considered as a viable alternative to preservatives. In this study, a health poultry-derived L. reuteri HLRE05 (lineage VI strain in the evolutionary branch) was used to confirm its ability to produce reuterin, and then its basic biological activity and inhibitory capacity against foodborne pathogens were evaluated by glycerol fermentation in in vitro and fermented milk. Results showed that L. reuteri HLRE05 exhibited high resistance to hydrogen peroxide and intestinal fluids, and its adhesion rate to intestinal epithelial cells (Caco-2) reached about 80%. The content of reuterin produced by glycerol fermentation in vitro reached to 9.98 mg/mL, and the addition of glycerol to the fermentation broth could significantly improve the ability of supernatant to inhibit common foodborne pathogens. In addition, reuterin inhibited enterotoxigenic B. cereus HN001 with concentration dependent manner and restricted its adhesion rate to intestinal epithelial cells. Furthermore, L. reuteri HLRE05 produced reuterin during milk fermentation and eradicated B. cereus HN001 in a short period of time. This study highlights the potential application of natural-sourced antimicrobial approach with specific L. reuteri HLRE05 to control the safety of dairy products. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Background Raw milk, meat and plant materials are subjected to high risks of contamination by various pathogenic bacteria and thus their growth prevention is a great challenge in the food industry. Food fermentation by lactic acid bacteria (LAB) besides changing its organoleptic characteristics also helps to eliminate unfavorable microflora and represses growth of pathogens. To the date only few LABs has been reported to exhibit activity against bacteria embedded in the biofilms characterized by extreme resistance to antimicrobials, high exchange rate with resistance genes and represent high risk factor for foodborne disease development. Results Six novel LAB strains isolated from the clover silage exhibited pronounced antibacterial activity against biofilm embedded pathogens. We show explicitly that these strains demonstrate high acidification rate, completely repress the growth of E. coli, S. aureus and to a lesser extent P. aeruginosa as well as exhibit appropriate probiotic and milk-fermenting properties. Moreover, in contrast to the approved probiotic strain Lactobacillus plantarum 8PA3, the new isolates were able to efficiently eradicate preformed biofilms of these pathogens and prevent bacterial spreading originating from the biofilm. We suggest these strains as potential additives to the pre-cultures of conventional LAB strains as efficient tools targeting foodborne pathogens in order to prevent food contamination from either seeded raw material or biofilm-fouled equipment. Conclusions The AG10 strain identified as L. plantarum demonstrate attractive probiotic and milk fermentation properties as well as high resistance to simulated gastric conditions thus appearing perspective as a starter culture for the prevention of bacterial contamination originating from fouled equipment during milk fermentation.

In this study, Enterococcus faecalis milk fermentates were assayed for total phenolic content, related antioxidant activity and the inhibition of key enzymes linked to hypertension and hyperglycaemia. Of the 25 isolates, milk fermented with E. faecalis DPC5154 had the highest level of total phenolic compounds (739.06 µg GAE/ml) and demonstrated the highest level of Trolox Equivalent Antioxidant Activity (TEAA) based on DPPH radical scavenging activity and ferric reducing antioxidant power (271.27 TEAA (µM) and 272.75 TEAA (µM), respectively). Inhibition of Angiotensin Converting Enzyme (ACE) and α-glucosidase is considered a useful therapeutic approach in the management of hypertension and hyperglycaemia, respectively. Milk fermented with DPC5154 completely inhibited ACE and displayed the highest level of α-glucosidase inhibitory activity (33.41%). These studies provide in vitro evidence for the beneficial use of DPC5154 and other E. faecalis isolates for the generation of bioactive milk products with antioxidant, antihypertensive and anti-hyperglycaemic activity.

This study aimed to investigate the effect of plant extracts (valerian Valeriana officinalis L., sage Salvia officinalis L., chamomile Matricaria chamomilla L., cistus Cistus L., linden blossom Tilia L., ribwort plantain Plantago lanceolata L., marshmallow Althaea L.) on the activity and growth of lactic acid bacteria (LAB) during the fermentation and passage of milk through a digestive system model. The tested extracts were also characterized in terms of their content of polyphenolic compounds and antioxidant activity. It was observed that the addition of the tested herbal extracts did not inhibit the growth of LAB in fermented milk drinks, such as yogurts. However, they can gradually inhibit fermentation when added at concentrations above 2% by weight, and hence should be used in limited amounts. The microflora of yogurts containing the tested herbal extracts did not die during digestion in model digestive juices, and no stimulating effect of the added plant extracts was noted either. Nevertheless, due to the antioxidant properties, a slight addition of the herbal extracts containing polyphenols to different kinds of food products can increase the nutritional quality, thus making them functional foods. [ABSTRACT FROM AUTHOR]

Despite the fact that strains belonging to Weissella species have not yet been approved for use as starter culture, recent toxicological studies open new perspectives on their potential employment. The aim of this study was to evaluate the ability of a wild Weissella minor (W4451) strain to modify milk viscosity compared to Lactobacillus delbrueckii subsp. bulgaricus, which is commonly used for this purpose in dairy products. To reach this goal, milk viscosity has been evaluated by means of two very different instruments: one rotational viscometer and the Ford cup. Moreover, water holding capacity was evaluated. W4451, previously isolated from sourdough, was able to acidify milk, to produce polysaccharides in situ and thus improve milk viscosity. The ability of W4451 to produce at the same time lactic acid and high amounts of polysaccharides makes it a good candidate to improve the composition of starters for dairy products. Ford cup turned out to be a simple method to measure fermented milk viscosity by small- or medium-sized dairies.

Enterococci are ubiquitous lactic acid bacteria (LAB) that predominantly reside in the gastrointestinal tract of humans and animals but are also widespread in food and the environment due to their robust nature. Enterococci have the paradoxical position of providing several benefits of technological interest in food fermentations but are also considered as opportunistic pathogens capable of causing infection in immunocompromised patients. Several species of the genus have been correlated with disease development in humans such as bacteremia, urinary tract infections, and endocarditis. The pathogenesis of enterococci has been attributed to the increasing incidence of antibiotic resistance and the possession of virulence determinants. On the contrary, enterococci have led to improvements in the aroma, texture, and flavor of fermented dairy products, while their beneficial use as probiotic and protective cultures has also been documented. Furthermore, they have emerged as important candidates for the generation of bioactive peptides, particularly from milk, which provide new opportunities for the development of functional foods and nutraceuticals for human nutrition and health. The detection of pathogenic traits among some species is compromising their use in food applications and subsequently, the genus neither has Generally Regarded as Safe (GRAS) status nor has it been included in the Qualified Presumption of Safety (QPS) list. Nevertheless, the use of certain enterococcal strains in food has been permitted on the basis of a case-by-case assessment. Promisingly, enterococcal virulence factors appear strain specific and food isolates harbor fewer determinants than clinical isolates, while they also remain largely susceptible to clinically relevant antibiotics and thus, have a lower potential for pathogenicity. Ideally, strains considered for use in foods should not possess any virulence determinants and should be susceptible to clinically relevant antibiotics. Implementation of an appropriate risk/benefit analysis, establishment of a strain's innocuity, and consideration for relevant guidelines, legislation, and regulatory aspects surrounding functional food development, may help industry, health-staff and consumers accept enterococci, like other LAB, as important candidates for useful and beneficial applications in food biotechnology. [ABSTRACT FROM AUTHOR]

Inulin is a natural product with beneficial effects for human health commonly used as a source of dietary fiber, bulking agent and fat substitute in products like cheese and yoghurt. There are some confusing or contradictory results in the literature about the water holding capacity of inulin and its effect on syneresis, coagulation kinetics, rheology and texture of yoghurt, so in this study those effects were evaluated. Yoghurt fermentation tests were conducted with three fat concentrations (0.4, 1.6 and 3.6%) and three inulin levels (0, 1.6 and 3.2%). The coagulation process was monitored for the first time using simultaneously an inline light backscatter sensor, inline potentiometry and a rheometer. The increase in milk fat concentration from 0 to 3.6% delayed the start of coagulation and increased time to pH=4.8 in 11 min. 3.2% of inulin addition increased yoghurt acidification rate, reduced 12 min the time to pH=4.8, and increased final storage modulus and gel firmness. It was also determined that 3.2% of inulin addition increased 32% the spontaneous syneresis and had no effect on the water holding capacity of set yoghurt. © 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved. [ABSTRACT FROM AUTHOR]

There is a constant increase in the attention being paid to food quality and the effects of food on human health among consumers. Vegetable milk is among the foods whose consumption worldwide has increased because, when compared to animal-derived milk, it offers numerous benefits for human health. The aim of this research work was to use vegetable milk to obtain yogurt-like products enriched with different concentrations of carob seed flour, which has a double function: to modify, and thus perfect, the rheological characteristics of vegetable-milk-based yogurt-like samples and to increase their nutritional value. The rheological parameters of the obtained samples were studied both in static and dynamic conditions, confirming that carob seed flour, especially at the highest used concentrations (0.75%; 1%), allows one to obtain products characterized by a good stability and suitable rheological characteristics. The obtained yogurt-like products may also be consumed by celiac subjects, since carob seed flour is a gluten-free flour, and allow celiac consumers to combine a gluten-free diet with a diet free of animal derivatives. Furthermore, the addition of carob flour allows one to obtain a tasty product thanks to the sweet taste of the carob seed flour. [ABSTRACT FROM AUTHOR]

Fermented milk has been shown to have beneficial effects on human health exerted through its bioactive peptides. The lactose-fermenting brown rot fungus Neolentinus lepideus has been shown to ferment milk; however, its ability to produce bioactive peptides has not been explored. This study, therefore, aimed to investigate the ability N. lepideus for the production of antihypertensive peptides in fermented milk and to characterize the peptides. Here we have used 9% skim milk as the substrate and fermented it with the mycelia of N. lepideus. The fermented milk exhibited higher angiotensin I-converting enzyme (ACE) inhibitory activity as compared to the commercially available sour milk containing Ile-Pro-Pro and Val-Pro-Pro. As a result of isolation and purification by reverse-phase high-performance liquid chromatography, followed by peptide sequencing and MS analysis, the dipeptide Tyr-Pro (YP) was identified as an active peptide. The concentration of YP in the fermented milk reached up to 450 μg/ml, which was > twofold higher than the IC50 for ACE inhibition. Subsequently, the antihypertensive effect of YP was validated through intravenous injection of the peptide, which exhibited a significant lowering of blood pressure in a rat model of genetic hypertension. In addition, the transcriptomic analysis revealed the probable role of the carboxypeptidases for the increased yield of YP. These results together indicated that the fermentation with basidiomycete fungus could be a viable approach to produce bioactive peptides, and may, therefore, be applicable in the development of a cost-effective mass production system for functional peptides. [ABSTRACT FROM AUTHOR]

Despite the fact that strains belonging to Weissella species have not yet been approved for use as starter culture, recent toxicological studies open new perspectives on their potential employment. The aim of this study was to evaluate the ability of a wild Weissella minor (W 4451) strain to modify milk viscosity compared to Lactobacillus delbrueckii subsp. bulgaricus , which is commonly used for this purpose in dairy products. To reach this goal, milk viscosity has been evaluated by means of two very different instruments: one rotational viscometer and the Ford cup. Moreover, water holding capacity was evaluated. W 4451, previously isolated from sourdough, was able to acidify milk, to produce polysaccharides in situ and thus improve milk viscosity. The ability of W 4451 to produce at the same time lactic acid and high amounts of polysaccharides makes it a good candidate to improve the composition of starters for dairy products. Ford cup turned out to be a simple method to measure fermented milk viscosity by small- or medium-sized dairies. [ABSTRACT FROM AUTHOR]

This study was carried out to investigate the contribution of two strains of Lactobacilli; Lactobacillus casei 431 and Lactobacillus acidophilus La-5 to the volatile organic compounds (VOCs) in fermented milk. The samples were subjected to the headspace-solid phase micro-extraction (HS-SPME) and gas chromatography mass spectrometry (GC-MS). Prior to the HS-SPME, four different silica fibres were screened for their ability to retain VOCs in the fermented milk. The fibre that retained the highest amount of VOCs was selected and used for the subsequent analyses. A total of 105 compounds made up of a wide range of VOCs such as acids, alcohols, aldehydes, aromatic compounds, esters and ketones were identified. The ketones were the most abundant group of compounds produced by the two strains of lactic acid bacteria (LAB) investigated. In addition, L. casei 431 was able to produce higher concentrations of typical flavour compounds like 2,3-butanedione, 2-heptanone, acetoin and 2-nonanone compared to L acidophilus La-5. As such, the ability of these strains to produce these distinct typical flavour compounds suggests their potential as starter cultures for the production of fermented dairy products with enhanced flavour/or aroma. [ABSTRACT FROM AUTHOR]

We analysed the correlations of milk fermentability (yogurt test acidity), renneting (time to rennet coagulation of milk protein) and results of ethanol tests (indirect indicator of milk thermostability) with the percentages of the milk components. The correlations of the milk component percentages with renneting were mostly weak, while the correlations with the ethanol test were even poorer. The CSN3 and LGB genotypes did not show a significant interaction in their influence on milk fermentability, renneting or ethanol test results. For the ethanol test, many significant interactions were observed between the DGAT1, LEP, FASN, SCD1, CSN2, CSN3 and LGB genotypes. DGAT1 interacted significantly with all genes for milk fermentability. For renneting that was measured instrumentally, CSN3 interacted significantly with DGAT1, FASN, SCD1, CSN2 A/B, CSN2 A1/A2; SCD1 interacted significantly with LEP and FASN. The breed and genotypes did not show any interactions. Farm and genotypes interacted significantly for all the technological properties studied; similar results were observed for the protein percentage and the genotypes, except that no interactions influenced the ethanol test results. [ABSTRACT FROM AUTHOR]

The present study aimed to analyze the effect of the addition of whole and milled flaxseed on the quality characteristics of yogurt. In the first stage of the research, the optimal dose of flaxseed was determined. In the second stage of the research, it was assessed whether the selected qualities of yogurt were affected by the form of flaxseed (whole or milled) and the time of addition (before or after fermentation). The yogurts obtained were stored at 5 °C for 21 days, and the changes in active acidity, apparent viscosity, syneresis, and the number of yogurt bacteria were determined. The results of the second stage of the study were subjected to two-way analysis of variance (ANOVA) (p < 0.05). The study showed that the addition of milled flaxseed to yogurts in the amount of 1% was optimal. Time and form of flaxseed supplementation significantly influenced the changes in active acidity, apparent viscosity, and syneresis in the tested yogurts. The addition of flaxseed did not significantly change the content of yogurt bacteria. The results indicate that to achieve increased apparent viscosity and reduced syneresis, it is more advantageous to use milled flaxseed rather than whole flaxseed.

The incorporation of prebiotics in fermented milk products is one of the best ways to promote health benefits while improving their sensory characteristics at the same time. The aim of this study was to evaluate the effects of the addition of fructose and oligofructose (1% and 2%) on the physicochemical, rheological, sensory, and microbiological quality attributes of fermented milk products inoculated with indigenous probiotic starter cultures of Lactobacillus isolated from Polish traditional fermented foods. The samples were evaluated during 35 days of refrigerated storage. The oligofructose and fructose caused increases in the populations of bacteria in comparison to the control fermented milk products without the addition of saccharides. The degrees of acidification in different fermented milk samples, as well as their viscosity, firmness, syneresis, and color attributes, changed during storage. The highest overall sensory quality levels were observed for the samples supplemented with L. brevis B1 and oligofructose. This study is the first attempt to compare the influences of different sugar sources on the physicochemical, rheological, sensory, and microbiological quality attributes of fermented milk products.

This study aimed to investigate the effect of plant extracts (valerian Valeriana officinalis L., sage Salvia officinalis L., chamomile Matricaria chamomilla L., cistus Cistus L., linden blossom Tilia L., ribwort plantain Plantago lanceolata L., marshmallow Althaea L.) on the activity and growth of lactic acid bacteria (LAB) during the fermentation and passage of milk through a digestive system model. The tested extracts were also characterized in terms of their content of polyphenolic compounds and antioxidant activity. It was observed that the addition of the tested herbal extracts did not inhibit the growth of LAB in fermented milk drinks, such as yogurts. However, they can gradually inhibit fermentation when added at concentrations above 2% by weight, and hence should be used in limited amounts. The microflora of yogurts containing the tested herbal extracts did not die during digestion in model digestive juices, and no stimulating effect of the added plant extracts was noted either. Nevertheless, due to the antioxidant properties, a slight addition of the herbal extracts containing polyphenols to different kinds of food products can increase the nutritional quality, thus making them functional foods.

Background: Raw milk, meat and plant materials are subjected to high risks of contamination by various pathogenic bacteria and thus their growth prevention is a great challenge in the food industry. Food fermentation by lactic acid bacteria (LAB) besides changing its organoleptic characteristics also helps to eliminate unfavorable microflora and represses growth of pathogens. To the date only few LABs has been reported to exhibit activity against bacteria embedded in the biofilms characterized by extreme resistance to antimicrobials, high exchange rate with resistance genes and represent high risk factor for foodborne disease development. Results: Six novel LAB strains isolated from the clover silage exhibited pronounced antibacterial activity against biofilm embedded pathogens. We show explicitly that these strains demonstrate high acidification rate, completely repress the growth of E. coli, S. aureus and to a lesser extent P. aeruginosa as well as exhibit appropriate probiotic and milk-fermenting properties. Moreover, in contrast to the approved probiotic strain Lactobacillus plantarum 8PA3, the new isolates were able to efficiently eradicate preformed biofilms of these pathogens and prevent bacterial spreading originating from the biofilm. We suggest these strains as potential additives to the pre-cultures of conventional LAB strains as efficient tools targeting foodborne pathogens in order to prevent food contamination from either seeded raw material or biofilm-fouled equipment. Conclusions: The AG10 strain identified as L. plantarum demonstrate attractive probiotic and milk fermentation properties as well as high resistance to simulated gastric conditions thus appearing perspective as a starter culture for the prevention of bacterial contamination originating from fouled equipment during milk fermentation. [ABSTRACT FROM AUTHOR]

• 25 E. faecalis fermented milk supernatants tested for bioactivity. • E. faecalis fermented milk had antioxidant, ACE and α-glucosidase inhibitory activity. • DPC5154 fermented milk demonstrated the highest level of antioxidants. • DPC5154 fermented milk completely inhibited angiotensin converting enzyme. • DPC5154 fermented milk had the highest level of α-glucosidase inhibitory activity. In this study, Enterococcus faecalis milk fermentates were assayed for total phenolic content, related antioxidant activity and the inhibition of key enzymes linked to hypertension and hyperglycaemia. Of the 25 isolates, milk fermented with E. faecalis DPC5154 had the highest level of total phenolic compounds (739.06 µg GAE/ml) and demonstrated the highest level of Trolox Equivalent Antioxidant Activity (TEAA) based on DPPH radical scavenging activity and ferric reducing antioxidant power (271.27 TEAA (µM) and 272.75 TEAA (µM), respectively). Inhibition of Angiotensin Converting Enzyme (ACE) and α-glucosidase is considered a useful therapeutic approach in the management of hypertension and hyperglycaemia, respectively. Milk fermented with DPC5154 completely inhibited ACE and displayed the highest level of α-glucosidase inhibitory activity (33.41%). These studies provide in vitro evidence for the beneficial use of DPC5154 and other E. faecalis isolates for the generation of bioactive milk products with antioxidant, antihypertensive and anti-hyperglycaemic activity. [ABSTRACT FROM AUTHOR]

Hyperuricemia, a condition characterized by elevated levels of uric acid in the blood, is known as a risk factor for gout disease. In this study, we isolated a total of 72 MRS-grown colonies and evaluated their purine nucleosidase (PNase) activity. Among the isolated bacteria, Levilactobacillus (L.) brevis LAB42 displayed the highest PNase activity. Our findings also indicate that PNase activity can vary among lactic acid bacterial strains and during different growth phases. Based on the kinetics study, LAB42 consistently exhibits the highest PNase activity. Due to its ability to attach to Caco-2 cells and its resistance to acidic environments and bile exposure, L. brevis LAB42 was chosen for further studies and showed that with the right combination of additives, it has the potential to be an appropriate starter for milk fermentation. [ABSTRACT FROM AUTHOR]