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Sucrose isomerase (SIase) catalyzes the hydrolysis and isomerization of sucrose to form isomaltulose, a valuable functional sugar widely used in the food industry. However, the lack of safe and efficient heterologous expression systems hinders SIase production and application. In this study, we achieved antibiotic-free SIase expression in Bacillus subtilis through genome integration. Using CRISPR/Cas9 system, SIase expression cassettes were integrated into various genomic loci, including amyE and ctc, both individually and in combination, resulting in single-copy and muti-copy integration strains. Engineered strains with a maltose-inducible promoter effectively expressed and secreted SIase. Notably, multi-copy strain exhibited enhanced SIase production, achieving 4.4 U/mL extracellular activity in shake flask cultivations. Furthermore, crude enzyme solution from engineered strain transformed high concentrations sucrose into high yields of isomaltulose, reaching a maximum yield of 94.6%. These findings demonstrate antibiotic-free SIase production in B. subtilis via genome integration, laying the foundation for its industrial production and application., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The α-glucosidase from Schwanniomyces occidentalis (GAM1p) was expressed in Komagataella phaffii to about 70 mg/L, and its transferase activity studied in detail. Several isomaltooligosaccharides (IMOS) were formed using 200 g/L maltose. The major production of IMOS (81.3 g/L) was obtained when 98% maltose was hydrolysed, of which 34.8 g/L corresponded to isomaltose, 26.9 g/L to isomaltotriose, and 19.6 g/L to panose. The addition of glucose shifted the IMOS synthesis towards products containing exclusively α(1 → 6)-linkages, increasing the production of isomaltose and isomaltotriose about 2-4 fold, enabling the formation of isomaltotetraose, and inhibiting that of panose to about 12 times. In addition, the potential of this enzyme to glycosylate 12 possible hydroxylated acceptors, including eight sugars and four phenolic compounds, was evaluated. Among them, only sucrose, xylose, and piceid (a monoglucosylated derivative of resveratrol) were glucosylated, and the main synthesised products were purified and characterised by MS and NMR. Theanderose, α(1 → 4)-D-glucosyl-xylose, and a mixture of piceid mono- and diglucoside were obtained with sucrose, xylose, and piceid as acceptors, respectively. Maximum production of theanderose reached 81.7 g/L and that of the glucosyl-xylose 26.5 g/L, whereas 3.4 g/L and only 1 g/L were produced of the piceid mono- and diglucoside respectively. KEY POINTS: • Overexpression of a yeast α-glucosidase producing novel molecules. • Yeast enzyme producing the heterooligosaccharides theanderose and glucosyl-xylose. • Glycosylation of the polyphenol piceid by a yeast α-glucosidase., (© 2024. The Author(s).)

Background: Isomaltulose is a 'generally recognized as safe' ingredient and is widely used in the food, pharmaceutical and chemical industries. The exploration and development of efficient technologies is essential for enhancing isomaltulose yield., Results: In the present study, a simple and efficient surface display platform mediated by a non-yeast signal peptide was developed in Yarrowia lipolytica and utilized to efficiently produce isomaltulose from sucrose. We discovered that the signal peptide SP1 of sucrose isomerase from Pantoea dispersa UQ68J (PdSI) could guide SIs anchoring to the cell surface of Y. lipolytica, demonstrating a novel and simple cell surface display strategy. Furthermore, the PdSI expression level was significantly increased through optimizing the promoters and multi-site integrating genes into chromosome. The final strain gained 451.7 g L -1 isomaltulose with a conversion rate of 90.3% and a space-time yield of 50.2 g L -1  h -1 ., Conclusion: The present study provides an efficient way for manufacturing isomaltulose with a high space-time yield. This heterogenous signal peptide-mediated cell surface display strategy featured with small fusion tag (approximately 2.2 kDa of SP1), absence of enzyme leakage in fermentation broth and ample room for optimization, providing a convenient way to construct whole-cell biocatalysts to synthesize other products and broadening the array of molecular toolboxes accessible for engineering Y. lipolytica. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

The amylosucrase (ASase, EC 2.4.1.4) utilizes sucrose as the sole substrate to catalyze multifunctional reactions. It can naturally synthesize α-1,4-linked glucans such as amylose as well as sucrose isomers with more favorable properties than sucrose with a lower intestinal digestibility and non-cariogenic properties. The amino acid sequence of the asase gene from Deinococcus cellulosilyticus (DceAS) exhibits low homology with those of other ASases from other Deinococcus species. In this study, we cloned and expressed DceAS and demonstrated its high activity at pH 6 and pH 8 and maintained stability. It showed higher polymerization activity at pH 6 than at pH 8, but similar isomerization activity and produced more turanose and trehalulose at pH 6 than at pH 8 and produced more isomaltulose at pH 8. Furthermore, the molecular weight of DceAS was 226.6 kDa at pH 6 and 145.5 kDa at pH 8, indicating that it existed as a trimer and dimer, respectively under those conditions. Additionally, circular dichroism spectra showed that the DceAS secondary structure was different at pH 6 and pH 8. These differences in reaction products at different pHs can be harnessed to naturally produce sucrose alternatives that are more beneficial to human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2024 Elsevier B.V. All rights reserved.)

Sucrose isomerase (SIase) catalyzes the hydrolysis and isomerization of sucrose into isomaltulose, a functional sugar extensively used in the food industry. However, the lack of safe and efficient heterologous expression systems for SIase has constrained its production and application. In this study, an engineered Bacillus subtilis strain for antibiotic-free SIase production was developed via a food-grade expression system. First, the B. subtilis strain TEA was modified through the CRISPR/Cas9 system, resulting in a mutant strain TEA4, which exhibited enhanced capabilities for recombinant protein expression. For efficient and safe production of SIase, different constitutive and inducible promoters were evaluated. The maltose-inducible promoter Poglv was found to have an extracellular SIase activity of 21.7 U mL -1 in engineered strain TEA4. Subsequent optimization of the culture medium further increased SIase activity to 26.4 U mL -1 during shake flask cultivation. Eventually, using the crude enzyme solution of the engineered strain in biotransformation reactions resulted in a high yield of isomaltulose under high concentrations sucrose, achieving a maximum yield of 83.1%. These findings demonstrated an engineered B. subtilis strain for antibiotic-free SIase production, paving the way for its scale-up industrial production and application., (© 2024 Wiley‐VCH GmbH.)

We evaluated changes in hyperhydration and beverage hydration index (BHI, a composite measure of fluid balance after consuming a test beverage relative to water) during resting, induced by the consumption of beverages containing glycerol and sodium supplemented with fast-absorbing sucrose or slow-absorbing isomaltulose. In a randomized crossover, single-blinded protocol (clinical trials registry: UMIN000042644), 14 young physically active adults (three women) consumed 1 L of beverage containing either 7% glycerol + 0.5% sodium (Gly + Na), Gly + Na plus 7% sucrose (Gly + Na + Suc), Gly + Na plus 7% isomaltulose (Gly + Na + Iso), or water (CON) over a 40 min period. We assessed the change in plasma volume (ΔPV), BHI (calculated from cumulative urine output following consumption of water relative to that of the beverage), and blood glucose and sodium for 180 min after initiating ingestion. Total urine volume was reduced in all beverages containing glycerol and sodium compared to CON (all P  ≤ 0.002). The addition of isomaltulose increased BHI by ∼45% (3.43 ± 1.0 vs. 2.50 ± 0.7 for Gly + Na, P  = 0.011) whereas sucrose did not (2.6 ± 0.6, P  = 0.826). The PV expansion was earliest for Gly + Na (30 min), slower for Gly + Na + Suc (90 min), and slowest for Gly + Na + Iso (120 min) with a concomitant lag in the increase of blood glucose and sodium concentrations. Supplementation of beverages containing glycerol and sodium with isomaltulose but not sucrose enhances BHI from those of glycerol and sodium only under a resting state, likely due to the slow absorption of isomaltulose-derived monosaccharides (i.e., glucose and fructose).

Carbohydrate (CHO) supplementation during endurance exercise can improve performance. However, it is unclear whether low glycemic index (GI) CHO leads to differential ergogenic and metabolic effects compared with a standard high GI CHO. This study investigated the ergogenic and metabolic effects of CHO supplementation with distinct GIs, namely, (a) trehalose (30 g/hr), (b) isomaltulose (30 g/hr), (c) maltodextrin (60 g/hr), and (d) placebo (water). In this double-blind, crossover, counterbalanced, placebo-controlled study, 13 male cyclists cycled a total of 100 min at varied exercise intensity (i.e., 10-min stages at 1.5, 2.0, and 2.5 W/kg; repeated three times plus two 5-min stages at 1.0 W/kg before and after the protocol), followed by a 20-min time trial on four separated occasions. Blood glucose and lactate (every 20 min), heart rate, and ratings of perceived exertion were collected throughout, and muscle biopsies were taken before and immediately after exercise. The results showed that trehalose improved time-trial performance compared with placebo (total work done 302 ± 39 vs. 287 ± 48 kJ; p = .01), with no other differences between sessions (all p ≥ .07). Throughout the 100-min protocol, blood glucose was higher with maltodextrin compared with the other supplements at all time points (all p < .05). Heart rate, ratings of perceived exertion, muscle glycogen content, blood glucose, and lactate were not different between conditions when considering the 20-min time trial (all p > .05). Trehalose supplementation throughout endurance exercise improved cycling performance and appears to be an appropriate CHO source for exercise tasks up to 2 hr. No ergogenic superiority between the different types of CHO was established.

Endothelin-1 (ET-1), produced by vascular endothelial cells, plays a pivotal role in the regulation of vascular tone. Isomaltulose, a naturally occurring sweetener and structural isomer of sucrose, reduces postprandial hyperglycemia, but its effect on arteriosclerosis due to hyperglycemia is unknown. The effects of 12 weeks of isomaltulose administration on ET-1 levels, a peptide that regulates arterial stiffness, blood pressure, and vascular tone, were tested before and after an oral glucose tolerance test. Fifty-four healthy middle-aged and older adults (30 men and 24 women) were divided into two groups: (1) a 25 g isomaltulose jelly drink intake group (Group I, 27 participants, mean age 55 ± 1 years) and (2) a sucrose jelly drink intake group (Group S, 27 participants, mean age 55 ± 1 years), each consuming isomaltulose or sucrose daily for 12 weeks, and a randomized, controlled study was conducted. Participants visited the laboratory before the intervention and 4, 8, and 12 weeks after the intervention to measure carotid-femoral (cf) and brachial-ankle (ba) pulse wave velocity (PWV), systolic blood pressure (BP), plasma glucose (PG), insulin, and ET-1 levels before and 60 and 120 min after a 75-g OGTT. baPWV, and ET-1 levels before intervention were significantly increased after 75-g OGTT compared to before 75-g OGTT in both groups (p < 0.05). The post-intervention baPWV, and ET-1 levels were significantly increased after 75-g OGTT in Group S compared to before 75-g OGTT (p < 0.05), whereas no significant changes were observed in Group I. These results suggest that consumption of isomaltulose, which has a lower GI than sucrose, is more effective in preventing the increases in systemic arterial stiffness associated with postprandial hyperglycemia in healthy middle-aged and older adults., (© 2023. Springer Nature Japan KK, part of Springer Nature.)

Scope: Secretion of the gut hormones glucagon-like peptide (GLP-1) and peptide YY (PYY) are induced by nutrients reaching the lower small intestine which regulate insulin and glucagon release, inhibit appetite, and may improve β-cell regeneration. The aim is to test the effect of a slowly digested isomaltulose (ISO) compared to the rapidly digested saccharose (SAC) as a snack given 1 h before a standardized mixed meal test (MMT) on GLP-1, PYY, glucose-dependent insulinotropic peptide (GIP), and metabolic responses in participants with or without type 2 diabetes (T2DM)., Methods and Results: Fifteen healthy volunteers and 15 patients with T2DM consumed either 50 g ISO or SAC 1 h preload of MMT on nonconsecutive days. Clinical parameters and incretin hormones are measured throughout the whole course of MMT. Administration of 50 g ISO as compared to SAC induced a significant increase in GLP-1, GIP, and PYY responses over 2 h after intake of a typical lunch in healthy controls. Patients with T2DM showed reduced overall responses of GLP-1 and delayed insulin release compared to controls while ISO significantly enhanced the GIP and almost tripled the PYY response compared to SAC., Conclusion: A snack containing ISO markedly enhances the release of the metabolically advantageous gut hormones PYY and GLP-1 and enhances GIP release in response to a subsequent complex meal., (© 2024 The Authors. Molecular Nutrition & Food Research published by Wiley-VCH GmbH.)

A novel cross-linked enzyme aggregates (CLEAs) catalyst was produced by precipitation and cross-linking sucrose isomerase (SIase) for isomaltulose production. The effects of precipitants and cross-linkers on the catalytic performance of the CLEAs were first evaluated. Then, bovine serum albumin (BSA) was used as additive and two immobilized enzymes, cross-linked SIase aggregates (CLSIAs) and CLSIAs-BSA were obtained. All the immobilized preparations exhibited superior thermal stability, pH tolerance, and storage stability compared to the soluble SIase, and showed excellent reusability. These samples still retained more than 61% of their initial activity after ten reuse cycles, with CLSIAs-BSA retaining up to 91.7%. The conversion ratios of sucrose into isomaltulose using CLSIAs-BSA reached 88.4 and 81.2% with sucrose and sugar cane juice as substrate, respectively. Therefore, CLSIAs are a highly effective biocatalyst for the preparation of isomaltulose with great potential for industrial applications., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Evidence regarding the effect of isomaltulose on glycemic and insulinemic responses is still conflicting, which limits isomaltulose's application in glycemic management. The purpose of this study was to comprehensively evaluate its effectiveness and evidence quality. We systematically searched PubMed, Embase, and the Cochrane Library for randomized controlled trials (RCTs) prior to October 2021. RCTs were eligible for inclusion if they enrolled adults to oral intake of isomaltulose or other carbohydrates dissolved in water after an overnight fast and compared their 2-h postprandial glucose and insulin concentrations. The DerSimonian-Laird method was used to pool the means of the circulating glucose and insulin concentrations. Both random-effects and fixed-effects models were used to calculate the weighted mean difference in postprandial glucose and insulin concentrations in different groups. Subgroup, sensitivity, and meta-regression analyses were also conducted. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess the certainty of evidence. Finally, 11 RCTs (n = 175 participants) were included. The trials were conducted in 4 countries (Japan, Brazil, Germany, and the Netherlands), and all of the enrolled participants were >18 y of age with various health statuses (healthy, type 2 diabetes, impaired glucose tolerance, and hypertension). Moderate evidence suggested that oral isomaltulose caused an attenuated glycemic response compared with sucrose at 30 min. Low evidence suggested that oral isomaltulose caused an attenuated but more prolonged glycemic response than sucrose and an attenuated insulinemic response. Low-to-moderate levels of evidence suggest there may be more benefit of isomaltulose for people with type 2 diabetes, impaired glucose tolerance, or hypertension; older people; overweight or obese people; and Asian people. The study was registered on PROSPERO (International Prospective Register of Systematic Reviews) as CRD42021290396 (available at https://www.crd.york.ac.uk/prospero/)., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society for Nutrition.)

Food-grade isomaltulose exhibits significant modulation of gut microbiota and its metabolites in healthy populations. This study further explored the preventive therapeutic effect and anti-colitis potential of isomaltulose on dextran sulfate sodium-induced colitis in mice. Our results suggested that isomaltulose played a significant role in preventing colon shortening, reducing intestinal epithelial destruction and inhibiting inflammatory cell infiltration. Meanwhile, the isomaltulose supplement greatly reduced the production of pro-inflammatory cytokines and restored the balance between T helper type 17 (Th17) cells and regulatory T (Treg) cells. Pathway enrichment analysis for differentially expressed genes (DEGs) also indicated that the anti-inflammatory effect of isomaltulose was closely related to intestinal immunity. Moreover, the disturbed gut microbiota in ulcerative colitis (UC) was partially restored after treatment with isomaltulose. These results suggest that isomaltulose is a promising therapeutic agent for the prevention and adjunctive treatment of UC by maintaining intestinal immune homeostasis and remodeling the gut microbiota.

A high-energy-type oral dietary supplement (ONS), with a low proportion of available carbohydrate (LC-ONS), which contains a slowly digestible carbohydrate, isomaltulose, and is fortified with soluble dietary fiber, was newly developed for individuals with diabetes or prediabetes. This study aimed to evaluate the impact of LC-ONS on blood glucose levels after ingestion in individuals with prediabetes. A single-blind, randomized crossover clinical trial was performed on 20 individuals with prediabetes. After overnight fasting, all subjects ingested one serving (200 kcal/125 mL) of either LC-ONS (40% energy proportion of available carbohydrates) or standard ONS (ST-ONS, 54% energy proportion of available carbohydrates) on two separate days. The incremental area under the curve of blood glucose levels for 120 min was significantly lower after LC-ONS ingestion compared to ST-ONS (2207 ± 391 mg/dL·min (least mean square value ± standard error) and 3735 ± 391 mg/dL·min, respectively; p < 0.001). The LC-ONS showed significantly lower blood glucose levels than the ST-ONS at all time points, except at baseline. Similarly, the incremental area under the curve of plasma insulin was significantly lower after LC-ONS ingestion. These results suggest that LC-ONS is useful as an ONS for energy supply in individuals with postprandial hyperglycemia.

Isomaltulose is a potential substitute for sucrose, with a high stability and prebiotic potential, for wide use in candies and soft drinks. This sugar is obtained from sucrose through enzymatic conversion using microbial glucosyltransferases. This work aimed to optimize a matrix to immobilize glucosyltransferase producing Erwinia sp. D12 cells using a sequential experimental strategy. The cell mass of Erwinia sp. D12 obtained in a bioreactor was immobilized in beads formed by ionic gelation. The conversion of sucrose into isomaltulose using the beads was performed in batch and continuous processes, and the isomaltulose was recovered through crystallization. The stability of isomaltulose was assessed in beverages of different pH values, and its prebiotic potential was verified with the growth of probiotic microorganisms. The optimized matrix composed of alginate (2.0% w/v), CaCl 2 (2.0% w/v), gelatin (2.0% w/v), and transglutaminase (0.2% w/v) showed the highest mean of produced isomaltulose (199.82 g/L) after four batches. In addition, high stability during the continuous process resulted in an isomaltulose production above of 230 g/L for up to 72 h. The produced isomaltulose was more stable than sucrose in lemon soft drink and orange and grape energy drinks after 30 days of storage; and promoted the growth of Bifidobacterium animalis and Lactobacillus lactis. In conclusion, the production of isomaltulose by Erwinia sp. D12 cells immobilized using optimized conditions is recommended, due to its high conversion capacity, high stability, and prebiotic potential of crystals obtained., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Isomaltulose is a low glycemic and insulinaemic carbohydrate now used as an alternative sweetener in beverages. However, it remains unclear if hydration status may be impacted differently with the consumption of beverages containing isomaltulose as compared to sucrose, a common beverage sweetener. Thirteen young adults (7 women) consumed 1 L of a carbohydrate beverage (with low electrolyte content) containing either 6.5%-sucrose, 6.5%-isomaltulose, or water within a 15 min period. For each beverage, beverage hydration index (BHI, a composite measure of fluid balance after consuming a test beverage relative to water) was calculated from urine volume produced over a 3 h period following ingestion of the carbohydrate beverages relative to water. The change in plasma volume (ΔPV), blood glucose, and lactate concentrations were assessed every 30 min post-beverage consumption. Isomaltulose ingestion attenuated urine production as compared to water and sucrose (P ≤ 0.005) over the 3 h post-ingestion period. However, no differences were observed between sucrose and water (P = 0.055). BHI was 1.53 ± 0.44 for isomaltulose (P ≤ 0.022 vs. sucrose and water) and 1.20±0.29 for sucrose (P = 0.210 vs. water). A transient reduction in ΔPV was observed following the ingestion of the isomaltulose beverage (at 30 min, P = 0.007 vs. sucrose). Thereafter, no differences in ΔPV between beverages were measured. Increases in blood glucose and lactate, indices of absorption and utility of glucose, were delayed in the isomaltulose as compared to sucrose beverage. In summary, we demonstrated a greater BHI with a carbohydrate-electrolyte beverage containing isomaltulose as compared to sucrose. This may in part be attributed to a delayed absorption of isomaltulose reducing diuresis., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Consumers are concerned with the amount of sucrose added to foods and its effects on human health. One way to reduce this concern is through the consumption of sucrose substitutes, such as isomaltulose. Isomaltulose is an alternative sugar that should be regarded by the food industry as much healthier than sucrose, due to its beneficial properties; these include, low glycemic index and slow hydrolysis, prebiotic potential, and low cariogenic potential. In this work, a bibliometric analysis associated with a review of literature was conducted as a rigorous method for exploring and analyzing large volumes of scientific data, to understand the global scenario and identify the trends regarding isomaltulose. Important facts from its history and origin were discussed, as well the main research and countries that have contributed to its growing interest in the food industry. Over the years, from the discovery of new beneficial properties, more studies have been conducted, demonstrating that the interest in isomaltulose has been increasing. Finally, we concluded that isomaltulose is a promising sucrose substitute that could change the scenario of the sugar-rich foods market; and its use for the development of new products is highly encouraged., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Obtaining a sucrose isomerase (SIase) with high catalytic performance is of great importance in industrial production of isomaltulose (a reducing sugar). In order to obtain such SIase mutant, a high-throughput screening system in microtiter plate format was developed based on a widely used 2,4-dinitrosalicylic acid (DNS) method for determination of reducing sugar. An SIase from Erwinia sp. Ejp617 (ErSIase) was selected to improve its catalytic efficiency. After screening of ~ 8000 mutants from a random mutagenesis library, Q209 and R456 were identified as beneficial positions. Saturation mutagenesis of the two positions resulted in a double-site mutant ErSIase&#95;Q209S-R456H that showed the highest catalytic efficiency, and its specific activity reached 684 U/mg that is 17.5-fold higher than that of the wild-type ErSIase. By employing the lyophilized Escherichia coli (E. coli) cells harboring ErSIase&#95;Q209S-R456H, a high space-time yield (STY = 3.9 kg/(L·d)) was achieved toward 600 g/L sucrose. Furthermore, the in silico analysis suggested that the hydrogen bond network was improved and steric hindrance was reduced due to the beneficial substitutions.Key points• A sucrose isomerase mutant with high catalytic efficiency was obtained.• The highest space-time yield was achieved toward high-concentration sucrose.• The optimized H-bond network contributed to the enhanced catalytic efficiency., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Sucrose isomerase (SIase) is a key enzyme used for the production of isomaltulose from sucrose. In this study, an SIase gene from Erwinia sp. Ejp617 (ErSIase) was heterologously expressed in Escherichia coli BL21(DE3), and the recombinant ErSIase was served as biocatalyst combined with the graphene oxide (GO) as carrier for ErSIase immobilization. The Fourier transform infrared spectroscopy, transmission electron microscope, and confocal laser microscopy analyses showed that ErSIase was successfully immobilized on the surface of GO to form ErSIase-GO. The loading capacity of ErSIase on GO reached up to 460 mg/g with a specific activity of 727.04 U/mg protein when the optimal immobilization time of 12 h and the ErSIase/GO ratio of 7.4:4 (w/w) were applied. A high conversion rate of 95.3% was reached from sucrose to isomaltulose using ErSIase-GO as biocatalyst with 600 g/L sucrose as substrate, after 180 min at 40 °C and pH 6.0. Moreover, stabilities of the immobilized ErSIase-GO in the aspects of thermal, pH, and storage were improved, and its activity after 10 batches still remained around 80% under the optimal conditions. The K m value of ErSIase-GO was 29.32 mM, and the k cat /K m was increased to 27.34 s -1  mM -1 when 0.1% (w/v) detergent NP40 was added. These results indicated that the ErSIase was well immobilized onto GO, and the ErSIase-GO is a promising biocatalyst with high operational stability and catalytic activity for industrial production of isomaltulose., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Diabetes mellitus is the most common metabolic disorder contributing to significant morbidity and mortality in humans. Different preventive and therapeutic agents, as well as various pharmacological strategies or non-pharmacological tools, improve the glycemic profile of diabetic patients. Isomaltulose, d-tagatose, and trehalose are naturally occurring, low glycemic sugars that are not synthesized by humans but widely used in food industries. Various studies have shown that these carbohydrates can regulate glucose metabolism and provide support in maintaining glucose homeostasis in patients with diabetes, but also can improve insulin response, subsequently leading to better control of hyperglycemia. In this review, we discussed the anti-hyperglycemic effects of isomaltulose, D-tagatose, and trehalose, comparing their properties with other known sweeteners, and highlighting their importance for the development of the pharmaceutical and food industries.

Increased arterial stiffness during acute hyperglycemia is a risk factor for cardiovascular disease, but the type of carbohydrate that inhibits it is unknown. The purpose of this study was to determine the efficacy of low-glycemic-index isomaltulose on arterial stiffness during hyperglycemia in middle-aged and older adults. Ten healthy middle-aged and older adult subjects orally ingested a solution containing 25 g of isomaltulose (ISI trial) and sucrose (SSI trial) in a crossover study. In the SSI trial, the brachial-ankle (ba) pulse wave velocity (PWV) increased 30, 60, and 90 min after ingestion compared with that before ingestion ( p < 0.01); however, in the ISI trial, the baPWV did not change after ingestion compared with that before ingestion. Blood glucose levels 30 min after intake were lower in the ISI trial than in the SSI trial ( p < 0.01). The baPWV and systolic blood pressure were positively correlated 90 min after isomaltulose and sucrose ingestion ( r = 0.640, p < 0.05). These results indicate that isomaltulose intake inhibits an acute increase in arterial stiffness. The results of the present study may have significant clinical implications on the implementation of dietary programs for middle-aged and elderly patients.

Purpose: Isomaltulose is a low glycemic and insulinaemic carbohydrate available as a constituent in sports drink. However, it remains unclear whether postexercise rehydration achieved by isomaltulose drink ingestion alone differs as compared to other carbohydrates., Methods: Thirteen young men performed intermittent exercise in the heat (35 °C and relative humidity 40%) to induce a state of hypohydration as defined by a 2% loss in body mass. Thereafter, participants were rehydrated by ingesting drinks equal to the volume of body mass loss with either a mixture of 3.25% glucose and 3.25% fructose, 6.5% sucrose (SUC), or 6.5% isomaltulose (ISO) within the first 30 min of a 3-h recovery. The change in plasma volume (ΔPV) from pre-exercise baseline, blood glucose, and plasma insulin concentration were assessed every 30-min., Results: ΔPV was lower in ISO as compared to SUC until 90 min of the recovery (all P ≤ 0.038) with no difference thereafter (all P ≥ 0.391). The ΔPV were paralleled by concomitant changes in blood glucose levels that were greater in ISO as compared to other drinks after 90 min of the recovery (all P ≤ 0.035). Plasma insulin secretion, which potentially enhances renal sodium reabsorption and fluid retention, did not differ between the trials (interaction, P = 0.653). ISO induced a greater net fluid volume retention as compared to SUC (P = 0.010)., Conclusion: We showed that rehydration with an isomaltulose drink following exercise-heat stress induces comparable recovery of PV and a greater net fluid retention as compared to other drinks, albeit this response is delayed. The delayed water transport along with glucose absorption may modulate this response. This trial was registered in 25th Sep 2019 at https://www.umin.ac.jp/ as UMIN000038099. (249/250)., (© 2021. Springer-Verlag GmbH Germany, part of Springer Nature.)

Reduced Glycemic Index (GI) of breakfast has been linked to improved cognitive performance in both children and adult populations across the morning. However, few studies have profiled the post-prandial glycemic response (PPGR) in younger children. The aim of this study was to assess PPGR to breakfast interventions differing in GI in healthy children aged 5-7 years. Eleven subjects completed an open-label, randomized, cross-over trial, receiving three equicaloric test beverages (260 kcal) consisting of 125 mL semi-skimmed milk and 50 g sugar (either glucose, sucrose, or isomaltulose). On a fourth occasion, the sucrose beverage was delivered as intermittent supply. PPGR was measured over 180 min using Continuous Glucose Monitoring (CGM). The incremental area under the curve (3h-iAUC) was highest for the glucose beverage, followed by intermittent sucrose (-21%, p = 0.288), sucrose (-27%, p = 0.139), and isomaltulose (-48%, p = 0.018). The isomaltulose beverage induced the smallest Cmax (7.8 mmol/L vs. >9.2 mmol/L for others) and the longest duration with moderate glucose level, between baseline value and 7.8 mmol/L (150 vs. <115 min for others). These results confirm that substituting mid-high GI sugars (e.g., sucrose and glucose) with low GI sugars (e.g., isomaltulose) during breakfast are a viable strategy for sustained energy release and glycemic response during the morning even in younger children.

We attempted to develop an efficient method for producing isomaltose, a disaccharide consisting of an α-(1→6)-linkage, from starch by combining enzymes of known activity. We found that the combination of 1,4-α-glucan 6-α-glucosyltransferase from Bacillus globisporus N75 and isopullulanase from Aspergillus brasiliensis ATCC 9642 led to the efficient synthesis of isomaltose. Inclusion of isoamylase and cyclomaltodextrin glucanotransferase resulted in increased efficiency, with production yields exceeding 70%. Furthermore, we considered that isomaltooligosaccharides could be synthesized from starch by combining 1,4-α-glucan 6-α-glucosyltransferase from Paenibacillus sp. PP710 and isopullulanase. In reactions that additionally utilized isoamylase and α-amylase, the total concentration of product, which included a series of isomaltooligosaccharides from isomaltose to isomaltodecaose, was 131 m m, and the ratio of 6-linked glucopyranosyl bonds to all bonds was 91.7% at a substrate concentration of 10%. The development of these manufacturing methods will accelerate the industrial production of isomaltose and isomaltooligosaccharides., (© The Author(s) 2021. Published by Oxford University Press on behalf of Japan Society for Bioscience, Biotechnology, and Agrochemistry.)

A reduction in carbohydrate intake and low-carbohydrate diets are often advocated to prevent and manage diabetes. However, limiting or eliminating carbohydrates may not be a long-term sustainable and maintainable approach for everyone. Alternatively, diet strategies to modulate glycemia can focus on the glycemic index (GI) of foods and glycemic load (GL) of meals. To assess the effect of a reduction in glycemic load of a 24 h diet by incorporating innovative functional ingredients (β-glucan, isomaltulose) and alternative low GI Asian staples (noodles, rice)on glycemic control and variability, twelve Chinese men (Age: 27.0 ± 5.1 years; BMI:21.6 ± 1.8kg/m 2 ) followed two isocaloric, typically Asian, 24h diets with either a reduced glycemic load (LGL) or high glycemic load (HGL) in a randomized, single-blind, controlled, cross-over design. Test meals included breakfast, lunch, snack and dinner and the daily GL was reduced by 37% in the LGL diet. Continuous glucose monitoring provided 24 h glycemic excursion and variability parameters: incremental area under the curve (iAUC), max glucose concentration (Max), max glucose range, glucose standard deviation (SD), and mean amplitude of glycemic excursion (MAGE), time in range (TIR). Over 24h, the LGL diet resulted in a decrease in glucose Max (8.12 vs. 6.90 mmol/L; p = 0.0024), glucose range (3.78 vs. 2.21 mmol/L; p = 0.0005), glucose SD (0.78 vs. 0.43 mmol/L; p = 0.0002), mean amplitude of glycemic excursion (2.109 vs. 1.008; p < 0.0001), and increase in 4.5-6.5mmol/L TIR (82.2 vs. 94.6%; p = 0.009), compared to the HGL diet. The glucose iAUC, MAX, range and SD improved during the 2 h post-prandial window of each LGL meal, and this effect was more pronounced later in the day. The current results validate the dietary strategy of incorporating innovative functional ingredients (β-glucan, isomaltulose) and replacing Asian staples with alternative low GI carbohydrate sources to reduce daily glycemic load to improve glycemic control and variability as a viable alternative to the reduction in carbohydrate intake alone. These observations provide substantial public health support to encourage the consumption of staples of low GI/GL to reduce glucose levels and glycemic variability. Furthermore, there is growing evidence that the role of chrononutrition, as reported in this paper, requires further examination and should be considered as an important addition to the understanding of glucose homeostasis variation throughout the day.

T cell based treatments in the setting of allogenic haematopoietic stem cell transplantation (HSCT) have been used for decades. In addition, the use of chimeric antigen receptor (CAR) T cells has been introduced as a promising cancer immunotherapy. A prerequisite for many of these treatments is the ability to cryopreserve the cells safely and efficiently. In the present study, we compared freezing media combinations containing pentaisomaltose and 1-2 % DMSO (PIM1 and PIM2, respectively) to 10 % DMSO and commercially available cryosolutions (CS2 and CS10, Cryostor® containing 2 and 10 % DMSO, respectively) for cryopreservation of T cells. T cells isolated from buffy coats from healthy donors were cryopreserved with different freezing media and analysed for 1) viability immediately post-thaw and the following 24 h, 2) recovery, 3) proliferative potential and 4) migration towards a gradient of SDF-1α. The results showed that PIM2 was superior to 10 % DMSO and comparable to CS10 when assessing viability. Furthermore, the results indicated that the T cells cryopreserved with 10 % DMSO showed the lowest proliferative potential. The expression levels of CXCR3, CXCR4 and VLA-4 were similar in T cells independent of the freezing media used; however, T cells cryopreserved with PIM2 demonstrated the highest migratory potential. In summary, the combination of pentaisomaltose and 1-2 % DMSO improves the cryoprotective properties compared to 10 % DMSO while achieving comparable results with CS10 and even showing improved migration towards SDF-1α. Thus, our results show promising potential for pentaisomaltose in combination with low amounts of DMSO for the cryopreservation of T cells., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

A simple and efficient method was developed for the preparation of high-purity trehalulose from the waste syrup of isomaltulose production. The waste syrup was pre-treated with C18 solid-phase extraction, where 98% decolorization and 97% reducing sugar recovery were obtained, followed by hydrophilic interaction liquid chromatography separation on a cysteine-bonded zwitterionic column. Under optimized conditions, trehalulose was separated from isomaltulose isomer and prepared on a semi-preparative scale with >99% purity. The structure of the prepared trehalulose was subsequently confirmed by nuclear magnetic resonance, and three tautomers of trehalulose (α-D-glucosylpyranosyl-1,1-β-D-fructopyranose, α-D-glucosylpyranosyl-1,1-β-D-fructofuranose, and α-D-glucosylpyranosyl-1,1-α-D-fructofuranose) were detected and completely characterized by 13 C NMR spectroscopy for the first time in this study. The tautomerization of α-D and β-D type transition was observed by hydrophilic interaction liquid chromatography on an AdvanceBio Glycan Mapping column, with smaller particle size (2.7 μm). Furthermore, the prepared trehalulose was applied as a standard for trehalulose quantification during the sucrose conversion by Klebsiella sp. LX3. The combination of solid-phase extraction and hydrophilic interaction liquid chromatography offers a new avenue for the preparation of sugar isomers from complex natural or fermentation products., (© 2021 Wiley-VCH GmbH.)

This article analyses, the replacement of sucrose in muffins with nine different combinations of isomaltulose and oligofructose. Being a structural isomer of sucrose with approx. 50% of sucrose sweetness, isomaltulose is non-cariogenic and with a low glycemic profile but having the same calories as sucrose. Oligofructose is composed of fructose polymers, with a reduced caloric value and prebiotic effect. Specifically, height, percentage of alveoli, water content, A w , mechanical, and optical properties have been measured along with a sensory evaluation. The results showed that all combinations of sweeteners gave place to softer muffins than control ones. Moreover, isomaltulose caused a darkening of the products likely due to an enhancement of the Maillard reactions. The highest amount of isomaltulose and the absence of sucrose meant the worst score in sweetness and flavor due to the low sweetening powder of isomaltulose., (© 2021 Wiley Periodicals LLC.)

Isomaltulose is a low glycemic and insulinemic carbohydrate available as a constituent of sports drinks. However, it remains unclear whether thermoregulatory responses (sweating and cutaneous vasodilation) after isomaltulose drink ingestion differ from those of sucrose and water during exercise in a hot environment. Ten young healthy males consumed 10% sucrose, 10% isomaltulose, or water drinks. Thirty-five minutes after ingestion, they cycled for fifteen minutes at 75% peak oxygen uptake in a hot environment (30 °C, 40% relative humidity). Sucrose ingestion induced greater blood glucose concentration and insulin secretion at the pre-exercise state, compared with isomaltulose and/or water trials, with no differences during exercise in blood glucose. Change in plasma volume did not differ between the three trials throughout the experiment, but both sucrose and isomaltulose ingestions similarly increased plasma osmolality, as compared with water (main beverage effect, p = 0.040)-a key response that potentially delays the onset of heat loss responses. However, core temperature thresholds and slopes for heat loss responses were not different between the trials during exercise. These results suggest that ingestion of isomaltulose beverages induces low glycemic and insulinemic states before exercise but does not alter thermoregulatory responses during exercise in a hot environment, compared with sucrose or water.

Background: Isomaltulose has been discussed as a low glycaemic carbohydrate but evidence concerning performance benefits and physiological responses has produced varying results. Therefore, we primarily aimed to investigate the effects of isomaltulose ingestion compared to glucose and maltodextrin on fat and carbohydrate oxidation rates, blood glucose levels and serum hormone concentrations of insulin and glucose-dependent insulinotropic polypeptide (GIP). As secondary aims, we assessed running performance and gastrointestinal discomfort., Methods: Twenty-one male recreational endurance runners performed a 70-min constant load trial at 70% maximal running speed (V max ), followed by a time to exhaustion (TTE) test at 85% V max after ingesting either 50 g isomaltulose, maltodextrin or glucose. Fat and carbohydrate oxidation rates were calculated from spiroergometric data. Venous blood samples for measurement of GIP and insulin were drawn before, after the constant load trial and after the TTE. Capillary blood samples for glucose concentrations and subjective feeling of gastrointestinal discomfort were collected every 10 min during the constant load trial., Results: No between-condition differences were observed in the area under the curve analysis of fat (p = 0.576) and carbohydrate oxidation rates (p = 0.887). Isomaltulose ingestion led to lower baseline postprandial concentrations of blood glucose compared to maltodextrin (percent change [95% confidence interval], - 16.7% [- 21.8,-11.6], p < 0.001) and glucose (- 11.5% [- 17.3,-5.7], p = 0.001). Similarly, insulin and GIP concentrations were also lower following isomaltulose ingestion compared to maltodextrin (- 40.3% [- 50.5,-30.0], p = 0.001 and - 69.1% [- 74.3,-63.8], p < 0.001, respectively) and glucose (- 32.6% [- 43.9,-21.2], p = 0.012 and - 55.8% [- 70.7,-40.9], p < 0.001, respectively). Furthermore, glucose fluctuation was lower after isomaltulose ingestion compared to maltodextrin (- 26.0% [- 34.2,-17.8], p < 0.001) and glucose (- 17.4% [- 29.1,-5.6], p < 0.001). However, during and after exercise, no between-condition differences for glucose (p = 0.872), insulin (p = 0.503) and GIP (p = 0.244) were observed. No between-condition differences were found for TTE (p = 0.876) or gastrointestinal discomfort (p = 0.119)., Conclusion: Isomaltulose ingestion led to lower baseline postprandial concentrations of glucose, insulin and GIP compared to maltodextrin and glucose. Consequently, blood glucose fluctuations were lower during treadmill running after isomaltulose ingestion, while no between-condition differences were observed for CHO and fat oxidation rates, treadmill running performance and gastrointestinal discomfort. Further research is required to provide specific guidelines on supplementing isomaltulose in performance and health settings.

In vitro experiments have indicated prebiotic activity of isomaltulose, which stimulates the growth of probiotics and the production of short chain fatty acids (SCFAs). However, the absence of in vivo trials undermines these results. This study aims to investigate the effect of isomaltulose on composition and functionality of gut microbiota in rats. Twelve Sprague-Dawley rats were divided into two groups: the IsoMTL group was given free access to water containing 10% isomaltulose ( w/w ), and the control group was treated with normal water for five weeks. Moreover, 16S rRNA sequencing showed that ingestion of isomaltulose increased the abundances of beneficial microbiota, such as Faecalibacterium and Phascolarctobacterium , and decreased levels of pathogens, including Shuttleworthia . Bacterial functional prediction showed that isomaltulose affected gut microbial functionalities, including secondary bile acid biosynthesis. Targeted metabolomics demonstrated that isomaltulose supplementation enhanced cholic acid concentration, and reduced levels of lithocholic acid, deoxycholic acid, dehydrocholic acid, and hyodeoxycholic acid. Moreover, the concentrations of propionate and butyrate were elevated in the rats administered with isomaltulose. This work suggests that isomaltulose modulates gut microbiota and the production of SCFAs and secondary bile acids in rats, which provides a scientific basis on the use of isomaltulose as a prebiotic.

We aimed to study the effect of consuming an alcohol-free beer with modified carbohydrates composition (almost completely eliminating maltose and adding isomaltulose (16.5 g day -1 ) and resistant maltodextrin (5.28 g day -1 )) in gut microbiome, compared to regular alcohol-free beer in subjects with T2DM or prediabetes and overweight/obesity. This is a pilot, randomized, double-blinded, crossover study including a sub-sample of a global study with 14 subjects: (a) consuming 66 cl day -1 of regular alcohol-free beer for the first 10 weeks and 66 cl day -1 of modified alcohol-free beer for the next 10 weeks; (b) the same described intervention in opposite order. BMI homogeneously decreased after both interventions. Glucose and HOMA-IR significantly decreased just after the participants consumed modified alcohol-free beer. These findings were in the same line as those reported in the global study. Dominant bacteria at baseline were Bacteroidetes, Firmicutes, Proteobacteria and Tenericutes. Parabacteroides, from the Porphymonadaceae family, resulted as the feature with the greatest difference between beers (ANCOM analysis, W = 15). Feature-volatility analysis confirmed the importance of Parabacteroides within the model. Alcohol-free beers consumption resulted in an enhancement of pathways related to metabolism according to PICRUSt analysis, including terpenoid-quinone, lipopolysaccharides and N-glycan biosynthesis. Thus, an alcohol-free beer including the substitution of regular carbohydrates for low doses of isomaltulose and the addition of maltodextrin within meals significantly impacts gut microbiota in diabetic subjects with overweight or obesity. This could, at least partially, explain the improvement in insulin resistance previously found after taking modified alcohol-free alcohol.Clinical Trial Registration: Registered under ClinicalTrials.gov identifier no. NCT03337828.

Objective: To characterize a recombinant isomerase that can catalyze the isomerization of sucrose into isomaltulose and investigate its application for the enzymatic production of isomaltulose., Results: A sucrose isomerase gene from Erwinia sp. Ejp617 was synthesized and expressed in Escherichia coli BL21(DE3). The enzymatic characterization revealed that the optimal pH and temperature of the purified sucrose isomerase were 6.0 and 40 °C, respectively. The enzyme activity was slightly activated by Mn 2+ and Mg 2+ , but partially inhibited by Ca 2+ , Ba 2+ , Cu 2+ , Zn 2+ and EDTA. The kinetic parameters of K m and V max for sucrose were 69.28 mM and 118.87 U/mg, respectively. The time course showed that 240.9 g/L of isomaltulose was produced from 300 g/L of sucrose, and the yield reached 80.3% after bioreaction for 180 min., Conclusions: This recombinant enzyme showed excellent capability for biotransforming sucrose to isomaltulose at the substrate concentration of 300 g/L. Further investigations should be carried out focusing on selection of suitable heterologous expression system with the aim to improve its expression level.

We read with interest the publication by Lightowler et al [...].

We thank the authors Vorland, Kyle and Brown for their interest in our paper and their comments [...].

The effect on cognitive test scores of generating differences in postprandial glycaemia using test foods or beverages has been inconsistent. Methodological issues may account for some of the variable results requiring further investigation using strong study designs into the relationship between glycaemia and cognitive functioning. The objective of this study was to determine the effects of postprandial glycaemia on cognitive function by examining cognition after consumption of foods that differ only by the rate of digestion of available carbohydrate in a population of young adults. In a double-blind, randomised, crossover trial, sixty-five participants received trifle sweetened either with a higher-glycaemic index (GI) sugar (sucrose; GI 65) or a lower-GI sugar (isomaltulose; GI 34). Cognitive tests were completed prior to trifle consumption, and 60 and 120 min after. There was no between-trifle difference at 60 min in performance on free word recall (0·0 (95 % CI -0·6, 0·5)), short delay word recall (0·0 (95 % CI -0·5, 0·5)), long delay word recall (0·0 (95 % CI -0·6, 0·6)), letter-number sequence recall (0·3 (95 % CI - 0·2, 0·7)) and visuo-spatial recall (-0·2 (95 % CI -0·6, 0·2)) tests. At 120 min, no difference was detected in any of these tests. The participants performed 7·7 (95 % CI 0·5,14·9) s faster in Reitan's trail-making test B 60 min after the higher-GI trifle than the lower-GI trifle (P = 0·037). Our findings of a null effect on memory are generally consistent with other works in which blinding and robust control for confounding have been used.

In this study, we prepared palatinose-sucrose (PS) mixtures from sucrose by enzymatic bioconversion to improve the low sweetness of palatinose and to develop sweeteners that can lower blood sugar levels. We hypothesized that PS mixtures containing 30% or 50% palatinose might demonstrate improvement of hyperglycemia. The physiological changes in C57BL/6J mice fed with these concentrations of PS mixture were recorded. After feeding the mice the different diets for 5 weeks, the diet with a higher palatinose content was observed to have resulted in lower serum glucose levels. The expression levels of various genes and proteins related to hepatic lipogenesis and cholesterol homeostasis were measured. The diet containing the 50% PS mixture induced lower expression of HMGCR, CYP7A1, and PPARγ as compared to the diet containing the 30% PS mixture. In conclusion, the ingestion of palatinose resulted in lower lipid levels compared to that of sucrose; therefore, palatinose would be a good alternative to sucrose as a healthy sweetener. PRACTICAL APPLICATIONS: Palatinose (isomaltulose), along with tagatose, allulose, and allose, is a well-known sugar substitute. Many studies have reported that palatinose has various beneficial effects on postprandial glucose metabolism, such as glycemic index, fat accumulation, hyperglycemia, and hyperinsulinemia. Although there are many advantages, including desirable biological functions, palatinose has limitations as a complete alternative for sucrose because of higher production costs, lower solubility, and lower sweetness. Therefore, we aimed to investigate the possibility of developing a sucrose substitute by preparing PS mixtures bioconverted using α-glucosyltransferase from sucrose and to promote the industrial application of palatinose. Our results suggest that 50% palatinose syrup may be a new candidate as a sugar substitute for industrial application., (© 2020 Wiley Periodicals, Inc.)

GIP was proposed to play a key role in the development of non- alcoholic fatty liver disease (NAFLD) in response to sugar intake. Isomaltulose, is a 1,6-linked glucose-fructose dimer which improves glucose homeostasis and prevents NAFLD compared to 1,2-linked sucrose by reducing glucose-dependent insulinotropic peptide (GIP) in mice. We compared effects of sucrose vs. isomaltulose on GIP and glucagon-like peptide-1 (GLP-1) secretion, hepatic insulin clearance (HIC) and insulin sensitivity in normal (NGT), impaired glucose tolerant (IGT) and Type 2 diabetes mellitus (T2DM) participants. A randomized crossover study was performed in 15 NGT, 10 IGT and 10 T2DM subjects. In comparison to sucrose, peak glucose concentrations were reduced by 2.3, 2.1 and 2.5 mmol/l (all p < 0.05) and insulin levels were 88% (p < 0.01, NGT), 32% (p < 0.05, IGT) and 55% (T2DM) lower after the isomaltulose load. Postprandial GIP iAUC concentrations were decreased (56%, p < 0.01 in NGT; 42%, p < 0.05 in IGT and 40%,p < 0.001 in T2DM) whereas GLP-1 iAUC was 77%, 85% and 85% higher compared to sucrose (p < 0.01), respectively. This resulted in ∼35 - 50% improved insulin sensitivity and reduced insulinogenic index after isomaltulose, which correlated closely with improved HIC, respectively (r = 0.62, r=-0.70; p < 0.001). HIC was inversely related to GIP (r=-0.44, p < 0.001) and positively related to GLP-1 levels (r = 0.40, p = 0.001). CONCLUSION: Endogenously released GIP correlated with reduced, and GLP-1 with increased hepatic insulin extraction. Increased peripheral insulin levels may contribute to insulin resistance and obesity. We propose that the unfavorable effects of high glycemic index Western diets are related to increased GIP-release and reduced HIC., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to disclose., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background & Aims: The quality of carbohydrates has an essential role in nutritional management of type 2 diabetes mellitus (T2DM) because of its substantial impact on glucose homeostasis. Alcohol-free beer has beneficial bioactive components but it has a relatively high glycemic-index so its consumption is restricted in diabetic subjects. We aimed to explore the effect of an alcohol-free beer with modified carbohydrate composition almost completely eliminating maltose and adding isomaltulose (16.5 g/day) and a resistant maltodextrin (5.28 g/day) in comparison to a regular alcohol-free beer on glycemic control of diabetic subjects with overweight or obesity., Design: We randomized 41 subjects into two groups: a) consumption of 66 cL/day of; regular alcohol-free beer for the first 10 weeks and 66 cL/day of alcohol-free beer with modified carbohydrate composition for the next 10 weeks; b) the same described intervention in opposite order. There was a washout period for 6-8 weeks between the two interventions. Participants were counseled to adhere to a healthy diet for cardiovascular health and to increase physical activity. Clinical, biochemical, anthropometric, lifestyle and satiety assessments were performed at the beginning and at the end of each period., Results: Subjects showed significantly weight loss after the two ten weeks periods (-1.69 ± 3.21% and -1.77 ± 3.70% after experimental and regular alcohol-free beers, respectively, P = 0.881). Glucose and glycated hemoglobin did not significantly change after any period. Insulin concentrations and HOMA-IR significantly decreased (-11.1 [-21.3-4.64]% and -1.92 ± 32.8% respectively) after the intake of experimental alcohol-free beer but not after regular alcohol-free beer. Reductions remained statistically significant after adjusting for weight loss, energy intake, physical activity and intervention order. Subjects reported higher satiety scores after consuming experimental alcohol-free beer., Conclusions: An alcohol-free beer including the substitution of regular carbohydrates for low doses of isomaltulose and the addition of a resistant maltodextrin within meals led to an improvement in insulin resistance in subjects with T2DM and overweight or obesity., Clinical Trial Registration: The clinical trial has been registered in ClinicalTrials.gov (Identifier: NCT03337828)., (Copyright © 2019 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Hyperglycemia is linked to impaired arterial endothelial function (EF), an early sign of cardiovascular disease. We compared the efficacy of low-glycemic index isomaltulose (Palatinose™) with that of sucrose in modulating EF, as assessed by flow-mediated dilation (FMD). In this double-blinded cross-over study, 80 overweight mildly hypertensive subjects were randomized to receive 50 g of either isomaltulose or sucrose. On two non-consecutive days, brachial artery ultrasound FMD scans were obtained prior to and hourly (T0-T3) after carbohydrate load. Blood was drawn immediately after scanning. Glucose and insulin levels were analyzed. Overall, the FMD decrease was attenuated by isomaltulose compared to sucrose (ΔFMD = -0.003% and -0.151%; p > 0.05 for the interaction treatment x period). At T2, FMD was significantly higher after isomaltulose administration compared to that after sucrose administration (FMD = 5.9 ± 2.9% and 5.4 ± 2.6%, p = 0.047). Pearson correlations between FMD and blood glucose showed a trend for a negative association at T0 and T2 independently of the carbohydrate (r-range = -0.20 to -0.23, p < 0.1). Sub-analysis suggested a lower FMD in insulin-resistant (IR) compared to insulin-sensitive subjects. Isomaltulose attenuated the postprandial decline of FMD, particularly in IR persons. These data support the potential of isomaltulose to preserve the endothelial function postprandially and consequently play a favorable role in cardiovascular health., Competing Interests: E.d.G. has honorary consultancies with Atlantia Food CRO, COLSWE environmental sensors, AiREAS corporation and Municipality of Eindhoven, and the Departments of Clinical Epidemiology, Biostatistics and Bioinformatics, and Gastroenterolog, of the Amsterdam UMC—Academic Medical Centre. E.d.G. receives writing fees from Up-to-Date in Cardiology (Wolters Kluwer). E.d.G. is owner and employee of Imagelabonline & Cardiovascular. Imagelabonline served as a subcontractor for Atlantia Food CRO, Cork, Ireland in the present study. E.d.G. also received research grants from the AMC Research Foundation, Academic Medical Center—Amsterdam UMC, Bioactor BV, Pfizer, LSP-Quartz, and the Municipality of Eindhoven. Otherwise, E.d.G. has no disclosures to make. S.T. and L.S. are employees of BENEO GmbH/Südzucker Group. In this double-blinded study, source data were provided by Atlantia Food Clinical Trials CRO, Cork, Ireland. Primary data analysis and report generation were undertaken by Atlantia Food Clinical Trials CRO independently from the sponsor. The statistical analyses of this publication have been developed for BENEO GmbH, which was also the exclusive sponsor of the project. BENEO GmbH reserves the exclusive right to use the results and data for possible Health Claim requests.

A safe, efficient, environmentally friendly process for producing isomaltulose is needed. Here, the biocatalyst, sucrose isomerase (SIase) from Erwinia rhapontici NX-5, displayed on the surface of Bacillus subtilis 168 spores (food-grade strain) was applied for isomaltulose production. The anchored SIase showed relatively high bioactivity, suggesting that the surface display system using CotX as the anchoring protein was successful. The stability of the anchored SIase was also significantly better. Thermal stability analysis showed that 80% of relative activity was retained after incubation at 40 °C and 45 °C for 60 min. To develop an economical industrial fermentation medium, untreated beet molasses (30 g/L) and cold-pressed soybean powder (50 g/L) were utilised as the main broth components for SIase pilot-scale production. Under the optimal conditions, the productive spores converted 92% of sucrose after 6 h and the conversion rate was 45% after six cycles. Isomaltulose production with this system using the agricultural residues, untreated beet molasses and soybean powder, as substrates is cost-effective and environmentally friendly and can help to overcome issues due to the genetic background.

In the daily diet, sweeteners play an indispensable role. Among them, sucrose, a widely occurring disaccharide in nature, is a commonly used sweetener. However, the intake of sucrose can cause a rapid increase in blood glucose, which leads to a number of health problems. Therefore, there is an urgent need for possible alternatives to sucrose. Currently, four naturally occurring sucrose isomers, trehalulose, turanose, leucrose, and isomaltulose are considered to be possible alternatives to sucrose due to their suitable sweetness, potential physiological benefits, and feasible production processes. This review covers the properties of these alternative sweeteners, including their structure, sweetness, hydrolysis rate, toxicology, and cariogenicity, and exhibits their potential applications in chronic diseases management, anti-inflammatory supplement, prebiotic dietary supplement, and stabilizing agent. The biosynthesis of these sucrose isomers using carbohydrate-active enzymes and their industrial production processes are also systematically summarized.

Low-glycemic compared to high-glycemic diets have been shown to improve metabolic status and enhance fat oxidation. The randomized, double-blind, controlled intervention study aimed to evaluate the effects of an energy-reduced diet containing isomaltulose (ISO, Palatinose™) versus sucrose (SUC) on body weight loss. Sixty-four healthy overweight/obese adults were allocated to consume either 40g/d ISO or SUC added to an energy-reduced diet for 12 weeks. Anthropometric measurements, body composition, and energy metabolism were assessed at baseline and after 4, 8, and 12 weeks. Fifty participants (age: 40.7 ± 11.7 y; BMI: 29.4 ± 2.7 kg/m²) completed the study. During the 12 weeks, both groups significantly lost weight ( p < 0.001), which was more pronounced following ISO (-3.2 ± 2.9 vs. -2.1 ± 2.6 kg; p = 0.258). Moreover, for participants in the ISO group, this was accompanied by a significant reduction in fat mass (ISO: -1.9 ± 2.5, p = 0.005; SUC: -0.9 ± 2.6%, p = 0.224). The overall decrease in energy intake was significantly higher in the ISO compared to that in the SUC group ( p = 0.022). In addition, breakfast containing ISO induced a significantly lower increase in postprandial respiratory quotient (RQ) (mean incremental area under the curve (iAUC) 2h for ISO vs. SUC: 4.8 ± 4.1 vs. 6.9 ± 3.1, p = 0.047). The results suggest that ISO in exchange for SUC may help to facilitate body weight reduction, lower postprandial RQ associated with higher fat oxidation, and reduce energy intake., Competing Interests: S.T. and L.S. are employees of BENEO GmbH/Südzucker Group.

New Findings: What is the central question of this study? What are the effects of isomaltulose, an ingredient in carbohydrate-electrolyte beverages to maintain glycaemia and attenuate the risk of dehydration during exercise heat stress, on postexercise rehydration and physiological heat loss responses? What is the main finding and its importance? Consumption of a 6.5% isomaltulose-electrolyte beverage following exercise heat stress restored hydration following a 2 h recovery as compared to a 2% solution or water only. While the 6.5% isomaltulose-electrolytes increased plasma volume and plasma osmolality, which are known to modulate postexercise heat loss, sweating and cutaneous vascular responses did not differ between conditions. Consequently, ingestion beverages containing 6.5% isomaltulose-electrolytes enhanced postexercise rehydration without affecting heat loss responses., Abstract: Isomaltulose is a disaccharide carbohydrate widely used during exercise to maintain glycaemia and hydration. We investigated the effects of ingesting a beverage containing isomaltulose and electrolytes on postexercise hydration state and physiological heat loss responses. In a randomized, single-blind cross-over design, 10 young healthy men were hypohydrated by performing up to three 30 min successive moderate-intensity (50% heart rate reserve) bouts of cycling, each separated by 10 min, while wearing a water-perfusion suit heated to 45°C. The protocol continued until a 2% reduction in body mass was achieved. Thereafter, participants performed a final 15 min moderate-intensity exercise bout followed by a 2 h recovery. Following cessation of exercise, participants ingested a beverage consisting of (i) water only (Water), (ii) 2% isomaltulose (CHO-2%), or (iii) 6.5% isomaltulose (CHO-6.5%) equal to the volume of 2% body mass loss within the first 30 min of the recovery. Changes in plasma volume (ΔPV) after fluid ingestion were greater for CHO-6.5% compared with CHO-2% (120 min postexercise) and Water (90 and 120 min) (all P ≤ 0.040). Plasma osmolality remained elevated with CHO-6.5% compared with consumption of the other beverages at 30 and 90 min postexercise (all P ≤ 0.050). Urine output tended to be reduced with CHO-6.5% compared to other fluid conditions (main effect, P = 0.069). Rectal and mean skin temperatures, chest sweat rate and cutaneous perfusion did not differ between conditions (all P > 0.05). In conclusion, compared with CHO-2% and Water, consuming a beverage consisting of CHO-6.5% and electrolytes during recovery under heat stress enhances PV recovery without modulating physiological heat loss responses., (© 2019 The Authors. Experimental Physiology © 2019 The Physiological Society.)

Isomaltulose is mainly produced from sucrose by microbial fermentation, when the utilization of sucrose contributes a high production cost. To achieve a low-cost isomaltulose production, soy molasses was introduced as an alternative substrate. Firstly, α-galactosidase gene from Rhizomucor miehei was expressed in Yarrowia lipolytica, which then showed a galactosidase activity of 121.6 U/mL. Under the effects of the recombinant α-galactosidase, most of the raffinose-family oligosaccharides in soy molasses were hydrolyzed into sucrose. Then the soy molasses hydrolysate with high sucrose content (22.04%, w / w ) was supplemented into the medium, with an isomaltulose production of 209.4 g/L, and the yield of 0.95 g/g. Finally, by virtue of the bioremoval process using Pichia stipitis , sugar byproducts in broth were transformed into ethanol at the end of fermentation, thus resulting in high isomaltulose purity (97.8%). The bioprocess employed in this study provides a novel strategy for low-cost and efficient isomaltulose production from soybean molasses.

: Cane molasses is one of the main by-products of sugar refineries, which is rich in sucrose. In this work, low-cost cane molasses was introduced as an alternative substrate for isomaltulose production. Using the engineered Yarrowia lipolytica, the isomaltulose production reached the highest (102.6 g L - ¹) at flask level with pretreated cane molasses of 350 g L - ¹ and corn steep liquor of 1.0 g L - ¹. During fed-batch fermentation, the maximal isomaltulose concentration (161.2 g L - ¹) was achieved with 0.96 g g - ¹ yield within 80 h. Simultaneously, monosaccharides were completely depleted, harvesting the high isomaltulose purity (97.4%) and high lipid level (12.2 g L - ¹). Additionally, the lipids comprised of 94.29% C 16 and C 18 fatty acids, were proved suitable for biodiesel production. Therefore, the bioprocess employed using cane molasses in this study was low-cost and eco-friendly for high-purity isomaltulose production, coupling with valuable lipids.

Due to changing consumer habits, non-alcoholic beer is the fastest-growing market within the beverage industry. Different processing technologies for limiting the alcohol content of beer yield in completely different matrix compositions and sensory profiles. Especially the specific sensory attributes of palate fullness, mouthfeel, and the perception of harmony (ratio harmony between sweetness and sourness) of non-alcoholic beers are often described as atypical and unbalanced by the consumer. In addition to technological aspects, the matrix components represent a significant factor. Cereal-based beverages contain a complex mixture of various polymers that includes proteins, polyphenols, and polysaccharides. These polymers affect the sensory perception of beverages in terms of mouthfeel depending on their substance properties. This article reports the analytical characterization of the macromolecular profile of non-alcoholic beers to predict sensory differences in palate fullness and mouthfeel that arise because of variations in polymer profile and processing method. Therefore, asymmetric flow-field-flow-fractionation (FFF/AF4), multi-angle light-scattering (MALS), and refractive index measurements were used to characterize polymers in non-alcoholic beers. We observed significant differences in the ratio of low- to high-molar-mass polymers. These differences included a shift of the molar mass distribution towards higher molar masses for beers subjected to higher thermal loads during dealcoholization in a rectification column. Limited fermentation beers tended to be composed of more low-molar-mass polymers. Highly discriminating sensorial assessment schemes demonstrate the correlations between differences in macromolecular profile and specific sensory impressions like sweetness (basic taste), palate fullness and harmony. This trend is verified in the present study with spiking experiments using substances that are known to influence mouthfeel and palate fullness, such as beta-glucans, dextrins, isomaltulose, and other low-molar-mass sugars, may be controlled during the production process. These results confirm that the particular sensory attributes can be influenced by different classes of cereal-based substances, especially by varying their molar mass fractions and concentrations. Maltodextrins and β-glucan are shown to enhance palate fullness. Spiking with maltodextrin caused a lasting, smooth, and pleasant perception of mouthfeel; spiking with β-glucan resulted in a more viscous, thick perceived mouthfeel. However, spiking with isomaltulose led solely to a sweet taste (basic taste). These tests show more generally that AF4-MALS is a suitable analytical tool for understanding how the macromolecular fractions in cereal-based beverages are linked to sensory impressions. This type of assessment can be used to target the composition of polymer profiles, which can be a technological possibility to produce sensorily appealing high-quality non-alcoholic beers., (Copyright © 2018. Published by Elsevier Ltd.)

Isomaltulose production by bacterial fermentation was limited, due to generation of undesirable products and reduced yields. Isomaltulose production using sucrose isomerase (SIase) catalyzed methods was expected to be more applicable, but was hampered by low SIase activity and lack of a secreted SIase producer. Here, we aimed to obtain high levels of secreted SIase by overexpressing the SIase gene from Pantoea dispersa UQ68J in Yarrowia lipolytica, a successful host for efficient secretory expression, with a newly characterized strong constitutive promoter. After optimization of the culture medium, the engineered strain JD secreted SIase with an activity of 49.3 U/mL. The recombinant SIase was effectively immobilized onto polyvinyl alcohol-alginate, and the enzymatic activity recovery rate was up to 82.4%. The stability of the SIase was significantly improved by immobilization. Batch production of isomaltulose catalyzed by the immobilized SIase was performed under optimal conditions, generating 620.7 g/L isomaltulose with a yield of 0.96 g/g. The conversion rate of sucrose after 13 batches remained above 90%. These results demonstrated that the proposed SIase expression and immobilization method was promising in the industrial production of isomaltulose., (Copyright © 2018. Published by Elsevier B.V.)

Amorphous sucrose is a component of many food products but is prone to crystallize over time, thereby altering product quality and limiting shelf-life. A systematic investigation was conducted to determine the effects of two monosaccharides (glucose and fructose), five disaccharides (lactose, maltose, trehalose, isomaltulose, and cellobiose), and two trisaccharides (maltotriose and raffinose) on the stability of amorphous sucrose in lyophilized two-component sucrose-saccharide blends exposed to different relative humidity (RH) and temperature environmental conditions relevant for food product storage. Analyses included X-ray diffraction, differential scanning calorimetry, microscopy, and moisture content determination, as well as crystal structure overlays. All lyophiles were initially amorphous, but during storage the presence of an additional saccharide tended to delay sucrose crystallization. All samples remained amorphous when stored at 11% and 23% RH at 22 °C, but increasing the RH to 33% RH and/or increasing the temperature to 40 °C resulted in variations in crystallization onset times. Monosaccharide additives were less effective sucrose crystallization inhibitors relative to di- and tri-saccharides. Within the group of di- and tri-saccharides, effectiveness depended on the specific saccharide added, and no clear trends were observed with saccharide molecular weight and other commonly studied factors such as system glass transition temperature. Molecular level interactions, as evident in crystal structure overlays of the added saccharides and sucrose and morphological differences in crystals formed, appeared to contribute to the effectiveness of a di- or tri-saccharide in delaying sucrose crystallization. In conclusion, several di- and tri-saccharides show promise for use as additives to delay the crystallization kinetics of amorphous sucrose during storage at moderate temperatures and low RH conditions. PRACTICAL APPLICATION: Amorphous sucrose is desirable in a variety of food products, wherein crystallization can be problematic for texture and shelf-life. This study documents how different mono-, di-, and tri-saccharides influence the crystallization of sucrose. Monosaccharide additives were less effective sucrose crystallization inhibitors relative to di- and tri-saccharides. These findings increase the understanding of how different mono-, di-, and tri-saccharide structures and their solid-state properties influence the crystallization of amorphous sucrose and show that several di- and tri-saccharides have potential for use as sucrose crystallization inhibitors., (© 2018 Institute of Food Technologists®.)

Palatinose is a sucrose analog with a slower digestion rate than that of sucrose. For this reason, palatinose shows better effects on hepatic lipogenesis and cholesterol homeostasis compared with sucrose. We hypothesized that supplementation with palatinose instead of sucrose improves postprandial hyperglycemia and hyperinsulinemia in mice. Herein, we compared the digestion rates in vitro and observed physiological changes in vivo between sucrose- and palatinose-containing diets given to mice. Palatinose was hydrolyzed only by enzymes of the small intestine and was digested more slowly compared with sucrose in vitro. In mice, a diet containing palatinose resulted in significantly lower body weight gain and food efficiency rate values than those given a diet with sucrose. In this study, changes in serum biochemistry; hepatic fatty acid synthesis; cholesterol homeostasis; glucogenic, proinflammatory cytokines; and oxidative stress-related genes and proteins in the palatinose- and sucrose-fed mice were measured. Compared with the mice fed the sucrose diet, the palatinose diet resulted in lower serum glucose, insulin, and total cholesterol levels, as well as lower expression of several lipogenesis-related genes and proteins. Histological analysis of hepatic cells of palatinose-fed mice showed normal morphology. In conclusion, palatinose intake results in lower hepatic lipogenesis and better cholesterol homeostasis than the effects from sucrose., (Copyright © 2018 Elsevier Inc. All rights reserved.)