Physical instability remains a major challenge in fermented plant-based yoghurts in the absence of added texturizing agents. Cultures can improve water holding capacity (WHC) through production of exopolysaccharide (EPS). This study identified key genes required for sucrose-dependent EPS biosynthesis in Leuconostoc mesenteroides 399 and assessed their contribution to WHC during plant-based milk fermentation. A forward genetic screen for spontaneous mutants with reduced slime formation on sucrose agar identified a loss of function mutation in the predicted dextransucrase gene dsr1. Subsequent screening using the dsr1 mutant yielded isolates with mutations in a levansucrase gene, a major facilitator superfamily (MFS) transporter, or a ScrR family transcriptional repressor, each showing complete loss of EPS. These results indicated that only one dextransucrase and one levansucrase are the enzymes involved in EPS production under the conditions tested. Proteomic and RNA analyses showed that mutations in either the MFS or ScrR genes abolished sucrose-induced expression of these EPS biosynthetic enzymes. The MFS mutant displayed impaired growth on sucrose, consistent with a primary role in sucrose uptake. In fermentation assays, wild type L. mesenteroides 399 combined with an acidifying Lactococcus starter increased WHC in soy and almond milks supplemented with 2% sucrose, whereas no increase was observed in oat or rice milks. EPS defective mutants did not increase WHC in sucrose supplemented soy or almond milks, relative to controls. These findings define a sucrose responsive EPS regulatory pathway in L. mesenteroides 399 and demonstrate that dsr1 is essential for WHC improvement in plant-based milk fermentations.

Starch is a polysaccharide biopolymer whose structure-rheology relationships influence its functional behavior, including in vitro digestibility; however, small datasets often limit the accuracy of quantitative predictions. Here, the in vitro digestibility (0-1) of ten starch samples was modeled using molecular features (A-and B1-chain fractions and amylose content) and pasting/rheological features. Four tabular data-augmentation methods (FastML preset, Gaussian copula, tabular variational autoencoder, and conditional tabular generative adversarial network) were benchmarked using quality metrics, and the optimal approach generated 200 synthetic samples for model training. random forest, support vector regression, XGBoost, lightGBM, and neural network were optimized through grid search. Among these, the neural network demonstrated the best predictive performance (R-2 = 0.907). SNAP (Shapley Additive Explanations) analysis was then applied to interpret the trained model, identifying consistency index, setback viscosity, and peak viscosity as dominant contributors, highlighting the roles of gel strength and viscosity recovery. This frame-work offers a data-driven tool for the rapid screening and design of starch-based materials through small-sample exper-iments.

A chemical strategy depositing functional nanoemulsions onto Fe(III)-tannic acid (TA) priming layers enables the fabrication of polyphenolic composite nanocoatings. Optimization of the composition yields stable nanoemulsions (similar to 200 nm) utilizing a 1:1 trans-cinnamaldehyde/olive oil core and a lactoferrin shell. These nanoemulsions demonstrate superior colloidal stability, specifically maintaining dispersion stability for 7 days at room temperature, resisting heat up to 60 degrees C, and withstanding centrifugal shear forces. Notably, a 3-day incubation triggers interfacial conjugation between trans-cinnamaldehyde and lactoferrin. On Fe(III)-TA-primed surfaces, these nanoemulsions promote the uniform growth of multinary composite nanofilms. This methodology offers a versatile, biocompatible approach to developing tailored composite nanocoatings, establishing a robust platform for engineering functional interfaces in food and biomedical applications.

A total of 36 oleogels, made from various waxes and vegetable oils, were utilized as shortening substitutes in cookies, and machine learning incorporating three boosting models (AdaBoost, GBM, and XGBoost) was applied to predict their effects on the quality attributes of the cookies. Carnauba wax oleogels exhibited the highest melting temperature and contributed to stronger cookie texture, while beeswax oleogels produced cookies with greater spreadability and lower hardness. Similar hyperspectral patterns were observed across different waxes and oils, with distinct clustering based on the level of wax through principal component analysis. By preprocessing the hyperspectral data of oleogels, the performances of three machine learning boosting models were improved to predict cookie spreadability and hardness, achieving an R2 value of over 0.95. These findings demonstrate the effectiveness of integrating hyperspectral imaging and machine learning techniques for predicting the quality characteristics of baked goods when various oleogels are used as shortening replacers.

We present the draft genome sequence of Bremerella cremea LHWP2, a notable member of the Planctomycetes-Verrucomicrobia-Chlamydiae group, isolated from a dead ark clam. The 6,211,343-bp genome contains 5,304 coding gene sequences with a guanine-cytosine content of 56.5 %. The draft genome also reveals potential nitrogen metabolic pathways.

In this study, we explored the binding mechanism between tannic acid (TA) and gluten to apply TA as an ingredient in bread-making to evaluate its baking performance and starch digestion. The interaction was systematically investigated by analyzing binding affinity, binding mode, and matrix structure of the TA–gluten complex using fluorescence quenching, molecular docking, and confocal laser scanning microscopy. TA strongly interacted with gluten via non-covalent interactions, mainly hydrogen bonds, and formed the major hydrogen bonds with six different glutamines (Q32, Q108, Q313, Q317, Q317, and Q349), which play a critical role in gluten network construction among amino acid residues of gluten. Additionally, TA showed lower binding affinity toward glutenin (−10.4 kcal/mol) compared to gliadin (−8.9 kcal/mol), implying stronger binding with glutenin. Consequently, the interaction between TA and gluten created a dense and compact gluten network structure. It influenced baking performance, causing a decrease in bread loaf volume while an increase in firmness and lowering the starch digestion rate, increasing slowly digestible starch and resistant starch fractions. This study identified the binding mechanism of TA toward gluten and provides better insights into how to apply TA or perhaps other polyphenols to design functional bakery products to control starch digestion rate.

In this study, honey from Hedera rhombea was used as a sugar substitute in cookie-making to design functional cookies for controlling carbohydrate digestion. Honey from H. rhombea contained glucose (0.56±0.11 mg/mg), fructose (0.27±0.06 mg/mg), and phenolic compounds (46.61±0.05 mg gallic acid equivalents/100 g). When honey from H. rhombea was used as a sugar substitute in the cookie dough, it decreased the dough stability and increased the degree of softening from the farinograph compared with the control dough, which implies a weaker gluten network formation. Moreover, the honey influenced the baking performance by decreasing the spread ratio and hardness, resulting in the production of softer cookies with a dark yellow color. Finally, the cookies prepared with honey exhibited reduced amounts of reducing sugars against α-amylase because of the antioxidant activity of phenolic compounds within the honey, indicating slower carbohydrate digestion. These results provide insights into how to use honey as a sugar substitute to design functional foods for modulating the postprandial glycemic response.

Resistant starch type 3 (RS3), often found in cooked starchy food, has various health benefits due to its indigestible properties and physiological functions such as promoting the abundance of gut beneficial microbial flora and inhibiting the growth of intestinal pathogenic bacteria. However, it is challenging to develop starchy food with high RS3 content. This review aims to provide a detailed overview of current advancements to enhance RS3 content in starchy food and its effects of RS3 on gut microbiota. These approaches include breeding high-amylose cereals through gene editing techniques, processing, enzyme treatments, storage, formation of RS3 nanoparticles, and the incorporation of bioactive compounds. The mechanisms, specific conditions, advantages, and disadvantages associated with each approach and the potential effects of RS3 prepared by different methods on gut microbiota are summarized. In conclusion, this review contains important information that aims to provide guidelines for developing an efficient RS3 preparation process and promote the consumption of RS3-enriched starchy foods to improve overall health outcomes.

This study evaluated the positive effects of autumn olive berries (AOBs) extract on delaying aging by improving lipid metabolism in middle-aged Caenorhabditis elegans that had become obese due to a high-glucose (GLU) diet. The total phenolic content and DPPH radical scavenging abilities of freeze-dried AOBs (FAOBs) or spray-dried AOBs (SAOBs) were examined, and FAOBs exhibited better antioxidant activity. HPLC analysis confirmed that catechin is the main phenolic compound of AOBs; its content was 5.95 times higher in FAOBs than in SAOBs. Therefore, FAOBs were used in subsequent in vivo experiments. FAOBs inhibited lipid accumulation in both the young adult and middle-aged groups in a concentration-dependent manner under both normal and 2% GLU conditions. Additionally, FAOBs inhibited ROS accumulation in a concentration-dependent manner under normal and 2% GLU conditions in the middle-aged worms. In particular, FAOB also increased body bending and egg production in middle-aged worms. To confirm the intervention of genetic factors related to lipid metabolism from the effects of FAOB, body lipid accumulation was confirmed using worms deficient in the daf-16, atgl-1, aak-1, and akt-1 genes. Regarding the effect of FAOB on reducing lipid accumulation, the impact was nullified in daf-16-deficient worms under the 2% GLU condition, and nullified in both the daf-16- and atgl-1-deficient worms under fasting conditions. In conclusion, FAOB mediated daf-16 and atgl-1 to regulate lipogenesis and lipolysis in middle-aged worms. Our findings suggest that FAOB improves lipid metabolism in metabolically impaired middle-aged worms, contributing to its age-delaying effect.

PURPOSE:To test the hypothesis that oral ingestion of slowly digestible carbohydrates (SDCs) that reach the ileum triggers the ileal brake as indicated by delayed gastric emptying, reduced glycemic response, and decreased subjective appetite. METHODS:The study was a five-arm, randomized, double-blind, crossover trial with a 1-week washout period between treatments (n = 20; 9 females, 11 males). Five treatments consisted of three SDC ingredients [raw corn starch, isomaltooligosaccharide (IMO), sucromalt], and an IMO/sucromalt combination, shown in vitro to have slow and extended digestion profiles, and a rapidly digestible carbohydrate control (maltodextrin). Carbohydrates (26 g) were incorporated into yogurt [300 g total; carbohydrate (~ 77 g), fat (~ 0.2 g), and protein (~ 9 g)] with closely matched energy content (346 kcal) and viscosity (~ 30,000 cP). Outcomes were measured in a 4 h postprandial period. RESULTS:Mean gastric half-emptying times were moderately though significantly increased for the raw corn starch and IMO treatments (P < 0.05), but they could be sub-divided into larger effect responder (n = 11) and non-responder groups (n = 9). Longer time for glycemic response to return to baseline was associated with increased gastric half-emptying time in an exploratory subset of data removing gastric half-emptying times > 3.5 h (P = 0.02). No significant differences in appetite ratings were observed. CONCLUSION:SDCs caused slower gastric emptying rate through activation of the ileal brake, as closely matched semi-solid yogurts were used and only rate of carbohydrate digestion differed. Extending glycemic response through consumption of SDCs was associated with triggering the ileal brake. TRIAL REGISTRATION:ClinicalTrials.gov NCT03630445, August 2018, retrospectively registered.

In the present study, 14 structurally unique flavonoids were screened to systematically investigate structural requirements for selectively inhibiting human α-amylase versus α-glucosidase to obtain a slow but complete starch digestion for health benefit. The selective inhibition property of three flavonoids chosen against the two classes of starch digestive enzymes was confirmed through various analytical techniques - in vitro inhibition assay, fluorescence quenching, kinetic study, and molecular modeling. Considering the chemical structure of flavonoids, the double bond between C2 and C3 and OH groups at A5 and B3 are critical for the inhibition of α-amylase allowing flavonoids to lie parallel on the α-amylase catalytic active site, whereas the OH groups at B3 and C3 are important for α-glucosidase inhibition causing B-ring specific entry into the catalytic active site of α-glucosidase. Our findings provide insights into how to apply flavonoids to effectively control digestion rate for improving physiological responses.

Nowadays, carbohydrate-based foods have a negative consumer connotation and low carb diets have become a popular way to lose weight. Here, we show how digestible starch and flavonoids can be used as a dietary approach to manage food intake and weight gain through elevation of glucagon-like peptide-1 (GLP-1) secretion for gut-brain axis communication. This was achieved by extending the digestion of cooked starch to the distal small intestine using luteolin or quercetin as α-amylase-specific inhibitors with competitive inhibition mechanism. In a mouse model, extended and complete digestion produced a signature blunted glycemic profile that induced elevation of GLP-1 and positive regulation of hypothalamic neuropeptides with significantly reduced food intake and weight gain (p < 0.05). These findings represent a shift in paradigm of dietary carbohydrates from weight increasing to reducing, and have implications for industry and public health related to the design of carbohydrate-based foods/ingredients for managing obesity and diabetes.

In this study, structural specificity of flavonoids was investigated toselectively inhibit starch digestive enzymes to stimulate the ileal-brake by triggering glucagon-like peptide-1 (GLP-1) through distal small intestine starch digestion which can regulate food intake and appetite. The double bond between C2 and C3 on flavonoid’s chemical structure plays a critical role to inhibit human pancreatic α-amylase, leading to π-staking interaction. Meanwhile, the hydroxyl group at C3 on the backbone benzopyran ring is intimately related to inhibition of the mucosal α-glucosidases. This selective inhibition is likely the result of fundamental differences in the protein structures of α-amylase and α-glucosidases, as they belong to different glycosyl hydrolase Families 13 and 31 (GH13 and GH31). α-Amylase has the catalytic active siteslocated in wide and shallow grooves on the protein structure, while α-glucosidases possess the narrow and deep catalytic pocket. In an acute study done on mice, luteolin, which had thehigher degree of selectivity toward α-amylase, showed a slow and sustained postprandial glycemic response with a reduced blood glucose peak and extended high glucose profile, compared to 3’,4’-dihydroxylflavonol as the selective α-glucosidases specific inhibitor. Quercetin was inhibitory of both α-amylase and α-glucosidases.Glycemic profiles in mice confirmed in vitro analysis of the inhibitory selectivity of the flavonoids tested. Additionally, the extended glycemic response with luteolin was accompaniedthe higher secretion of GLP-1 at extended postprandial times by delivering more starch portion into the distal small intestine where the ileal-brake and gut-brain axis activation takes place. Overall, selective inhibition of α-amylase by flavonoids potentially could be considered as a key approach to control glucose release from starch with slow and extended, but still complete, digestion for improved glycemic response and minimized adverse side effects that result from severely restricting or even shutting down starch digestion by pharmaceutical grade inhibitors.

While gut bacteria have different abilities to utilize dietary fibers, the degree of fiber structural alignment to bacteria species is not well understood. Corn bran arabinoxylan (CAX) was used to investigate how minor polymer fine structural differences at the genotype x environment level influences the human gut microbiota. CAXs were extracted from 4 corn genotypes x 3 growing years and used in in vitro fecal fermentations. CAXs from different genotypes had varied contents of arabinose/xylose ratio (0.46-0.54), galactose (58-101 mg/g), glucuronic acid (18-32 mg/g). There was genotypebut not environment-specific differences in fine structures. After 24 h fermentation, CAX showed different acetate (71-86 mM), propionate (35-44 mM), butyrate (7-10 mM), and total short chain fatty acid (SCFA) (117-137 mM) production. SCFA profiles and gut microbiota both shifted in a genotype-specific way. In conclusion, the study reveals a very high specificity of fiber structure to gut bacteria use and SCFA production.

Waxy potato amylopectin has longer internal and external linear chains than rice or corn amylopectin that are capable of retrograding to a higher degree, but its molecular recrystallization is impeded by unprotonated phosphate groups. Here, we studied whether retrogradation and gel properties of waxy potato starch can be enhanced by lowering pH. The gel strength of waxy potato starch was strongly inversely correlated with pH, going from 10 to 4, and its magnitude was higher at pH values in which the zeta potential of the system was low. Waxy potato starch formed a strong aggregate gel driven by the formation of intermolecular double helices (G' drop(25-95 degrees C) approximate to 1358 Pa, melting Delta H = 9.5 J/g) when conditions that reduce electrostatic repulsion (pH 4, zeta = -1.7) are used, a phenomenon that was not observed in low-phosphorylated waxy cereal starches (i.e., waxy rice and corn).

An accurate high-performance anion-exchange chromatography (HPAEC) method is presented to measure the inhibition property of flavonoids against mammalian starch digestive enzymes, because flavonoids interfere with commonly used 3,5-dinitrosalicylic acid (DNS) and glucose oxidase/peroxidase (GOPOD) methods. Eriodictyol, luteolin, and quercetin increased absorbance values (without substrate) in the DNS assay and, with substrate, either overestimated or underestimated values in the DNS and GOPOD assays. Using a direct HPAEC measurement method, flavonoids showed different inhibition properties against α-amylase and α-glucosidases, showing different inhibition constants (Ki) and mechanisms. The double bond between C2 and C3 on the C-ring of flavonoids appeared particularly important to inhibit α-amylase, while the hydroxyl group (OH) at C3 of the C-ring was related to inhibition of α-glucosidases. This study shows that direct measurement of starch digestion products by HPAEC should be used in inhibition studies, and provides insights into structure-function aspects of polyphenols in controlling starch digestion rate.

A soluble crosslinked corn bran arabinoxylan matrix promotes butyrate and butyrogenic bacteria.

In this study we investigated the structural specificity of flavonoids for starch digestive enzyme inhibition to modulate glucose release from glycemic carbohydrate digestion. Using three different flavonoids [eriodictyol, luteolin, and quercetin], chosen based on the degree of hydroxylation and planarity of the C‐ring, structural specificities were found for selectively inhibiting α‐amylase and α‐glucosidases, resulting in different inhibition constants (Ki) and mechanisms. The double bond between C2 and C3 on the C‐ring of flavonoids was particularly important for α‐amylase inhibition, which leads to a π‐stacking interaction between flavonoids and α‐amylase, while the hydroxyl group at C3 of the C‐ring played a key role in inhibiting α‐glucosidases. These structural specificities of flavonoids toward starch degrading enzymes are likely the result of different protein structures of α‐amylase and α‐glucosidases, as they belong to different families, GH13 and GH31. Our findings provide insights into structure‐function aspects of flavonoids in controlling starch digestion rate.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Here, we reveal a new food gel formed on simple pH reduction of a water-soluble crosslinked corn bran arabinoxylan complex. This is different from low pH gelling high-methoxyl pectin that requires high sugar content, and it is similar in gelling property to low acyl gellan gum though is readily soluble in water. Alkaline-solubilized corn bran arabinoxylan (CAX) with two levels of residual bound ferulic acid was treated with laccase, a crosslinking enzyme, to produce two soluble, crosslinked CAX (SCCAX) complexes of different sizes (avg. 3.5 and 4.5-mer). Both of the SCCAXs formed gels at pH 2, with the larger, more heavily feruloylated SCCAX forming the stronger gel. Gels showed shear-thinning behavior and a thermal and pH reversible property. A gel forming mechanism was proposed to occur through noncovalent crosslinking including hydrogen bonds and hydrophobic interaction among the SCCAX complexes. This mechanism was supported by structural characterization of crosslinked CAX complexes using a Zeta-sizer and FT-IR spectroscopy. Applications of SCCAX gels might be where low pH low sugar gels are desired or a beverage containing SCCAX might be taken with gelling occurring in the low pH environment of the stomach, as well as in other food gels and as a drug delivery matrix.