Starch Digestibility Research Articles

Gut microbiota enable wood-feeding insects to digest recalcitrant diets. Two DNA-based analyses were performed. Amplicon sequencing of gut microbiota samples from Cryptocercus punctulatus showed inter-individual heterogeneity with visually distinct ordination patterns; however, no statistically significant differences were detected. Shotgun metagenomics was used to compare the taxonomic and functional profiles of C. punctulatus gut microbiota with those of other xylophagous Dictyoptera. Despite taxonomic differences, C. punctulatus microbiota revealed functional convergence with termites (Mastotermes darwiniensis and Nasutitermes sp.). Carbohydrate metabolism was performed by different bacterial phyla across all insects. All insect species possessed metabolic potential for cellulose, hemicellulose, pectin, and starch digestion, but lignin degradation capabilities were not detected. Termites showed higher abundance of chitin and xylan degradation pathways and nitrogen fixation genes, though nitrogen fixation was also present in Cryptocercus cockroaches. Genes for oxidative stress tolerance were present across all species but were most abundant in cockroaches, particularly, Cryptocercus. All insects harbored antibiotic resistance genes, with highest levels found in cockroaches. These findings indicate that metabolic requirements for wood digestion shape gut microbial community assembly across xylophagous insects, with distinct microbial taxa contributing to cellulose and hemicellulose breakdown. Moreover, the widespread presence of antibiotic resistance genes raises concerns about the potential transmission of antibiotic resistance within insect-associated microbiomes.

Resistant starch (RS), a major category of dietary fiber, promotes healthy lipid and glucose metabolism. These effects are partly mediated by gut microbes. RS is known to influence microbial bile acid metabolism and, in turn, can lower serum cholesterol. We hypothesized that RS may promote another microbial process that affects serum cholesterol levels – the cholesterol:coprostanol transformation pathway, which has not been fully characterized. Individuals who harbor gut microbes encoding a recently identified gene in the pathway, intestinal sterol metabolism A (ismA), can transform cholesterol to less absorbable coprostanol. Individuals with microbial ismA genes have lower serum cholesterol than people without microbial ismA genes. We conducted a seven-week crossover study with 59 individuals completing three treatments: dietary supplementation with RS type 2, RS type 4, and a digestible starch, for ten days each with five-day washout periods in between. We collected fecal samples at the beginning and end of each treatment and extracted DNA to generate a shotgun metagenomics dataset from the gut microbiomes. We also measured the concentrations of bile acids and the sterols, cholesterol and coprostanol, in the stool. RS supplementation caused interindividual variability in gut microbiome response. Also, during the RS type 2 treatment, we observed a decrease in taurocholic acid, a bile acid that may promote colon cancer (q < 0.05). RS supplementation did not universally affect sterol levels. However, we observed consistent correlations between the abundances of some microbes, or species level genome bins (SGBs), and sterol concentrations longitudinally within subjects. We identified 24 SGBs, including three Oscillibacter species, which were negatively correlated with cholesterol and positively correlated with coprostanol (Spearman's rho ≥ 0.4). In addition to its ability to transform cholesterol, Oscillibacter has previously been implicated as benefiting lipid metabolism and cardiovascular health. We also identified 12 unclassified SGBs that may be involved in the transformation of cholesterol to coprostanol in the human gut. These SGBs may represent previously undiscovered species that participate in the cholesterol:coprostanol transformation pathway, and these species may possess unknown genes in the pathway. Comprehensive characterization of this pathway could lead to novel microbiome-based therapeutics to treat hypercholesterolemia.

Gluten-free (GF) pasta alternatives are frequently limited in variety, availability, and physicochemical qualities when compared with wheat pasta. Egg white protein (EWP) serves as a nutritional and texturizing agent but its role in modulating the structural and functional properties of heat-moisture-treated (HMT) rice-flour based GF pasta remains underexplored. This study aimed to investigate the effects of EWP (2.5%, 5%, 7.5%, and 10%), with and without transglutaminase (TG) (0% and 1%) on the quality of HMT rice-flour-based pasta. The incorporation of egg white protein (with or without TG) restructured the protein-starch matrix, increasing optimal cooking time, water absorption, and swelling index. The EWP-enriched formulation increased firmness and chewiness to wheat-like levels while lowering cooking loss (CL) to less than 8% (threshold for 'good quality' pasta). At 10%, EWP (with or without TG) in the formulation enabled rice pasta to qualify as a protein source under EU regulations with reduced starch digestibility. Microstructurally, EWP with and without TG reduced starch crystallinity but promoted β-sheet network formation. Although TG reinforced the rice-EWP matrix by creating a denser network and delaying starch digestion, the overall pasta properties of EWP with TG remained similar to those without TG, with only minor differences. Overall, this study shows that EWP (with or without TG) can successfully improve HMT rice flour-based pasta, resulting in a wheat-like texture, low CL, and slower starch digestion. These findings support the scalable production of nutritionally enhanced GF pasta, particularly for gluten-sensitive and health-conscious consumers. © 2025 Society of Chemical Industry.

ABSTRACT Background and Objectives Wheat germination enhances its α‐amylase activity affecting the functional properties of flour and bread. Studies reported a variety of germination conditions, which does not allow comparison studies. This study evaluated the impact of germination on wheat flour functionality, breadmaking performance, and nutritional quality using peak viscosity after heating as a marker to control the degree of germination. Findings Wheat kernels were germinated until peak viscosity was reduced by 50% compared to control. A strong negative correlation was found between α‐amylase activity and peak viscosity ( r = −0.84, p < 0.0001), and a strong positive correlation between peak viscosity and falling number ( r = 0.98, p < 0.0001), validating the use of peak viscosity as a predictor of enzymatic starch degradation. Bread from fixed time germinated flour showed varying reductions in hardness and chewiness, whereas bread from adjusted germinated flour demonstrated more consistent levels. Conclusions Viscosity‐adjusted germination effectively controls enzymatic activity and influences both dough handling and bread texture. It also leads to slower starch hydrolysis. Significance and Novelty Peak viscosity is proposed as a practical and quantitative marker of wheat germination level. By controlling enzymatic activity through viscosity adjustment, it is possible to optimize bread quality and nutritional outcomes.

Partially gelatinized corn and potato starch show faster digestibility after retrogradation.

Effects of exogenous amyloid protein fibril aggregates on in vitro digestibility, structural properties and retrogradation of starch in extruded reconstituted rice.

Improvement of physicochemical, structural, and digestive properties of gluten-free starch dough by adding egg white protein and dry heat treatment.

Impact of extrusion-induced protein molecular rearrangement on cooking qualities, in vitro digestibility and gluten allergenicity of durum wheat pasta.

Mechanism of reducing rice starch digestibility by quinoa protein amyloid-like fibrils pretreated with magnetic field.

Deproteinization and controlled starch prehydrolysis in intact pulse cotyledon cells regulates starch retrogradation and digestion.

Slow starch digestibility promotes the development of favorable feeding behaviors and metabolic health in mice.

Positively charged components (chitosan most potently) combined with annealing: Modulating digestibility and viscosity of corn starch

The expanding production of Changshan Huyou (Huyou) products has resulted in large quantities of by-products, particularly peel residues, posing challenges for environmental sustainability and resource utilization. Current uses of Huyou peel residues focus mainly on the extraction of pectin and flavonoids, yet substantial precipitates remain unutilized. Meanwhile, the growing demand for health-conscious diets has increased interest in high-fiber bread due to its benefits for glycemic control and gut health. This study employs a low-temperature acid extraction method to recover the precipitate-Huyou fiber-after pectin extraction, thereby improving the utilization of peel residues. Compared with commercial citrus fiber, Huyou fiber demonstrates comparable thermal stability and viscosity at higher concentrations (3%). Incorporating moderate amounts (<5%) of Huyou fiber into bread formulations enhances dough cohesiveness and elasticity and lowers the gelatinization temperature of dough compared with the control (without added fiber), increases slowly digestible and resistant starch contents, and significantly reduces the estimated glycemic index (eGI) (from 78.3±0.8 to 68.6±1.0, p<0.05). These findings support the high-value utilization of Huyou peel residues and underscore the potential of Huyou fiber as a functional ingredient for developing low-GI bakery products. PRACTICAL APPLICATIONS: This research converts abundant Huyou peel waste into functional fiber. Compared to common citrus fiber, Huyou fiber holds up better during baking (superior heat stability) and helps create a softer texture (higher viscosity). Adding a small amount (<5%) to bread maintains good texture while significantly lowering its blood sugar impact. This offers bakers a way to turn waste into value and provides consumers with more nutritious baked goods.

In vitro inhibitory effects of polyphenols from Fagopyrum tataricum (L.)Gaertn. on starch-digesting enzymes: Action mechanism, isothermal titration calorimetry, and molecular docking analysis.

35. Improving starch digestibility in phytase-supplemented wheat-barley diets with canola or soybean meal using xylanase/glucanase, protease, and their combination for post-weaning piglets

Effects of high hydrostatic pressure on starch: multi-scale structures, interactions and applications.

Effect of NaHCO3 on the quality and in vitro starch digestibility of fried-free instant noodles.

Native versus processed oat endosperm microstructures: mechanisms driving starch digestibility and gelatinization behavior

Analysis of the mechanism of starch gelatinization, disintegration and component interaction during roasting processing of Chinese traditional oat food.

Recrystallization of optimized debranched starch: Effects of concentration on resistant starch formation and structural properties.