Effect of rare sugars on physical and sensory properties of doughs and biscuits

Effect of cell culture medium pH on rare sugar production and enhanced bioactive polysaccharide capacity from Arachis pintoi-associated bacteria

Yogurt is a popular dairy product, common the world over, and usually consumed sweetened in the US market. Due to a growing interest in lower calorie dairy products, we investigated consumers' interest in yogurt sweetened with rare sugars such as tagatose and allulose, which can be synthesized enzymatically from lactose removed from the same milk used to make the yogurt, but contain fewer digestible calories than sucrose. A series of 2 consumer sensory tests were carried out on yogurts sweetened with sucrose, sucralose (the most popular artificial sweetener in the US), stevia (the most popular natural low -calorie sweetener), and either single rare sugarsor in blends typical of incomplete enzymatic conversion from lactose. Additionally, a conjoint analysis examined consumers' implicit choices around sweetened yogurt made with such ingredients, and how these factors influenced their willingness to pay. Results showed that grams of added sugar displayed on labels were an important driver of selection, supported by a strong negative effect on purchase intent (PI) for high added sugar samples in the in person sensory test when information was provided. Rare sugars, whether in blends or alone, elicited high liking scores, which were even higher when information on their caloric and added sugar content was revealed. Results suggest that rare sugars can be used to more closely approximate the flavor profiles of sucrose-sweetened products, while retaining a natural claim. PRACTICAL APPLICATIONS: Consumers desire lower calorie food products with fewer grams of added sugars, and natural ingredients. Rare sugars offer a promising option for sucrose replacement, providing a sensory profile in yogurt more similar to that of sucrose than most popular artificial or natural low calorie sweeteners. Consumers were willing to pay more for such products and viewed them as more appealing than samples sweetened with sucralose or stevia.

Retrofitting Escherichia coli for de novo production of rare L-sorbose from abundant D-glucose.

Cannabis polysaccharides (CPs): Extraction methods, structural characteristics, biological activities and structure-function relationship: A review.

Whey permeate, a dairy industry co-product rich in lactose, represents an underutilized resource for the production of value-added ingredients. Free enzymes can catalyze its conversion, but suffer from limited stability and reusability, restricting industrial application. Enzyme immobilization provides a strategy to overcome these limitations. In this study, cross-linked enzyme aggregates (CLEA) of β-galactosidase and glucose isomerase were developed, optimized, and characterized as carrier-free biocatalysts for the transformation of lactose into a sweetener blend of glucose, galactose, and fructose. β-galactosidase and glucose isomerase CLEAs were successfully formed, yielding CLEAs densities of 30 mg and 10 mg of wet CLEA/mL, respectively, and demonstrating recyclability with activity retention after seven cycles. Applied in a batch process to whey permeate (40 mM lactose), the CLEAs enabled complete hydrolysis of lactose within 15 min at 60°C and progressive isomerization of glucose into fructose, reaching a fructose concentration of 8 mM after 7 h. These findings highlight the potential of CLEAs as efficient, recyclable biocatalysts for lactose up cycling, contributing to the sustainable valorization of dairy co-products into blended sweeteners and other value-added ingredients. PRACTICAL APPLICATIONS: This research presents an alternative approach for the valorization of whey permeate into value-added ingredients to be used directly as sweeteners or further transformed into rare sugars. Additionally, the study explores the variables influencing enzyme immobilization and describes the optimization of CLEA for use in whey permeate valorization, offering a reusable alternative to free enzymes.

Efficient production of D-tagatose through cell membrane permeabilization modification and multi-enzymes compartmentalization.

Highly efficient production of l-rhamnose from catalytic hydrolysis of marine polysaccharide ulvan over carbon embedded sulfonated resins.

D-tagatose is a rare sugar found in nature that contains less than one-third of sucrose's calories while maintaining 92% of its sweetness. Owing to its physiological properties, such as lowering blood sugar, preventing obesity, anti-caries, and regulation of intestinal flora, it is being used as a new kind of healthy sweetener. This paper conducts a systematic review of advances in its biosynthesis research, focusing on the catalytic mechanisms of key enzymes and the multi-substrate conversion strategies. Specifically, by analyzing L-Arabinose Isomerase (L-AI), the study compares enzymatic conversion pathways for various substrates, including monosaccharides (D-galactose, D-fructose, D-glucose, etc.), disaccharides (lactose, sucrose), and maltodextrin. This study thoroughly examines the advantages and limitations of each pathway in terms of reaction efficiency, substrate cost, and industrial adaptability. The goal of this research is to provide guidance for D-tagatose's industrial manufacturing, advancing its efficient biosynthesis and commercial application.

Synthesis of alduronic acid lactones and rare sugar glyconolactones via decarboxylative oxygenation of uronic acids: Construction of polyhydroxylated fused-ring alkaloids

Assessing a strategy to recover trehalulose sugar from stingless bee honey Geniotrigona thoracica sp. via cation exchange adsorption.

Rare sugars have gained attention as attractive alternatives to conventional sugars due to their potential health benefits and lower caloric value. However, their scarcity restricts widespread application, highlighting the need for efficient biosynthetic production strategies. In this study, a novel sucrose 6F-phosphate phosphorylase from Sphaerochaeta globosa strain Buddy was identified through sequence analysis within the glycoside hydrolase family GH13_18. Substrate screening revealed that this enzyme is capable of producing isomelezitose, a rare trisaccharide naturally found in honey, known for its osmoprotective and potential prebiotic properties. A proof-of-concept production at a 1 L scale, starting from cheap bulk sugars sucrose and isomaltulose, yielded 68 g of high-purity isomelezitose (>99%), which enabled a first evaluation of its properties as a food ingredient. Isomelezitose exhibited limited digestibility and a relative sweetness of 27% compared to sucrose. Moreover, its physicochemical properties were comparable to those of sucrose, including similar glass transition temperature, crystallinity, and flow/tribological behavior. To this end, isomelezitose might form an interesting opportunity as a sugar alternative in the food industry.

d-allulose, a low-calorie rare sugar produced by d-allulose 3-epimerase (DAE), has broad application potential, but its production is limited by the poor thermostability and immobilization efficiency of DAE. In this study, a multimerization-promoting tag (Mp-tag) was fused to the N-terminus of DAE from Ruminococcus sp. (RDAE), targeting the dimer-dimer interface of its tetrameric structure. The optimized triple mutant Mp-tag enhanced interdimer interactions, increasing the melting temperature from 64.9 °C (without Mp-tag) to 71.8 °C. Molecular dynamics simulations confirmed that Mp-tag stabilized tetramer formation by lowering interdimer binding free energy. To improve immobilization, a glutamate-rich immobilization-promoting tag (Ip-tag) was fused to the N-terminus of the Mp-tag, enhancing site-specific binding and increasing immobilized activity recovery by 30.69%. The resulting immobilized bifunctional-tagged enzyme retained over 90% activity after 500 reaction cycles. This strategy also proved effective for other tetrameric DAEs, demonstrating its general applicability for enhancing enzyme stability and immobilization in biocatalytic processes.

The main purpose of this review is to explore the potential of rare sugars as an innovative nutritional intervention for obesity-related type 2 diabetes mellitus (T2DM) and associated cardiometabolic diseases. The central research question is whether rare sugars, due to their unique metabolic properties, can serve as effective alternatives to traditional treatments, helping to manage or prevent T2DM while minimizing long-term side effects linked to anti-diabetic drugs. This review synthesizes evidence from in vitro, ex vivo, in vivo, and clinical studies to assess the effects of rare sugars on glucose metabolism, insulin sensitivity, lipid regulation, and overall cardiometabolic health. Studies were examined for their contributions to understanding the mechanistic pathways and therapeutic implications of rare sugars in comparison with conventional interventions. Evidence indicates that rare sugars differ significantly from regular sugars in their metabolic impact. Findings highlight their anti-hyperglycemic and anti-hyperlipidemic effects, with demonstrated improvements in insulin sensitivity and glucose regulation. Both animal and human studies suggest that rare sugars may reduce cardiometabolic risks associated with obesity and T2DM, supporting their role as promising functional sweeteners. Rare sugars present a novel and promising strategy for managing obesity-related T2DM and preventing cardiometabolic complications. While current evidence underscores their beneficial metabolic properties, more comprehensive clinical trials in diverse populations are necessary to validate their efficacy and safety in long-term use. These findings open a pathway for rare sugars to be considered as part of dietary strategies aimed at improving cardiovascular and metabolic health.

Recently, microbial fermentation for the synthesis of rare sugars has garnered considerable attention. d-Allose, a rare monosaccharide, has emerged as a significant bioproduct in the food and pharmaceutical industries due to its unique health benefits and physiological functions. However, the detection of d-allose in fermentation broth samples predominantly depends on complex chromatographic techniques. This study introduces a toggle-programmed microbial fluorescent biosensor designed for the dynamic monitoring of d-allose. The d-allose-sensing PalsR promoter, located within the alsRBACEK operon, was initially characterized and used as a core component in the biosensor. The native PT7 promoter and the PalsR promoter were then utilized for the expression of green fluorescent protein (GFP) and T7 RNA polymerase (T7 RNAP), respectively. The constitutive Ppdc promoter was employed to overexpress the repressor protein AlsR in the cytoplasm, thereby ensuring effective regulation of PalsR. More importantly, a fast-folding and fast-degrading mGFP-DAS replaced GFP as the reporter, facilitating a rapid response to d-allose during continuous microbial incubation. The results demonstrated that this novel biosensor exhibited high sensitivity to d-allose levels, with measurement deviation controlled within 15%. This approach offers significant advantages over traditional d-allose chromatography detection methods, particularly in terms of simplicity and cost-effectiveness.

We report a modular and stereodivergent synthesis of 6-deoxy-l-talose and 6-deoxy-l-gulose rare sugars via chemoselective glycosylation and regioselective dihydroxylation. Judicious variation of the C-4 substitution precisely controlled diastereoselectivity, enabling complementary access to both epimers. Proof-of-principle and synthetic versatility were demonstrated with carbohydrates, amino acids, natural products, and bioactive molecules, affording diverse rare sugar analogs. Late-stage functionalization of custom-tailored glycosides generated a library of rare sugar conjugates, including ferrocene hybrids, medicinally valuable scaffolds, and therapeutic agents.

IntroductionThe increased consumption of refined carbohydrates, particularly sucrose, has contributed to metabolic disorders and oral diseases such as dental caries by promoting dysbiotic biofilm formation and reducing microbial diversity. Allulose, a rare sugar with physicochemical properties similar to sucrose, has been suggested to offer metabolic health benefits; however, its impact on oral biofilm ecology remains unclear.MethodsWe evaluated the cariogenic potential of allulose using a multi-tiered in vitro platform consisting of single-species planktonic and biofilm models, a dual-species biofilm model involving Streptococcus mutans (pathogen) and Streptococcus oralis (commensal), and a saliva-derived microcosm biofilm model. Key virulence indicators, including bacterial growth, acid production, biofilm biomass, exopolysaccharide (EPS) synthesis, and microbial community composition, were quantitatively assessed.ResultsCompared to sucrose, glucose, and fructose, allulose supported reduced bacterial growth and acid production, showing a profile similar to non-fermentable sugar alcohols such as xylitol and erythritol. Biofilms developed under allulose conditions lacked the dense EPS-enmeshed microcolonies and dome-shaped architecture characteristic of sucrose-induced S. mutans-dominant biofilms. In the saliva-derived microcosm model, allulose-treated biofilms maintained higher microbial diversity and preserved health-compatible genera such as Neisseria, Haemophilus, Veillonella, and Granulicatella.DiscussionThese findings demonstrate that allulose supports lower bacterial virulence activity and minimal biofilm formation compared to common dietary sugars while preserving microbial diversity. This highlights its potential as a non-cariogenic sugar alternative with microbiome-conscious benefits and provides ecological insight into how allulose may modulate oral biofilm structure and function.

Dietary sugars induce the secretion of hepatic fibroblast growth factor 21 (FGF21) and subsequently activate FGF21‐sensing oxytocin neurons to suppress sugar intake. We aimed to identify FGF21‐inducing rare sugars as substitutes for obesogenic dietary sugars and to test their ability to suppress sugar appetite in BL/6 mice. We have identified D‐allulose, D‐tagatose, and D‐sorbitol as potent FGF21‐inducers in mouse primary hepatocytes. All three compounds were confirmed to induce FGF21 secretion and subsequently activate oxytocin neurons in mice. FGF21‐inducing rare sugars administered by gastric gavage to mice reduced sugar intake, and mixing these sugars with sucrose solution significantly reduced their intake and preference in mice. The long‐term lick analyses showed that an FGF21‐inducing sugar made the solution palatable, but reduced the appetite for the sugar solution and prolonged the ingestion interval in mice. Therefore, using these sugars as substitutes for obesogenic dietary sugars may help to curve sugar appetite and reduce sugar intake.

Sugar intake induces the secretion of fibroblast growth factor 21 (FGF21) from the liver. Subsequently, FGF21 acts on the hypothalamus to reduce sugar intake. As simple sugars are obesogenic, low-calorie rare sugars can be used as alternatives. Accordingly, D-allulose, D-tagatose, and D-sorbitol induce Fgf21 expression in primary mouse hepatocytes. Carbohydrate-responsive element-binding protein regulates simple sugar-induced FGF21 expression. Therefore, this study aimed to determine whether the same mechanism was responsible for rare sugar-induced FGF21 expression. Promoter analysis, knockdown assays, and chromatin immunoprecipitation were performed using primary mouse hepatocytes. Our findings demonstrate that these three rare sugars transactivate mouse Fgf21 promoter by inducing activating transcription factor 4 (ATF4), which binds to an amino acid response element located 1,027 base pairs upstream of the transcription start site. These results suggested a novel mechanism for sugar-induced FGF21 expression.

Mutational and structural analysis of ribose 5-phosphate isomerase B from Acetivibrio thermocellus: relationship between transformation efficiency and substrate binding pocket conformation.