Understanding the mechanism of change in morphological structures, visualization features, and physicochemical characteristics of adlay seeds (Coix lacryma-jobi L.): The role of heat soaking

New insights into adlay seed bran polysaccharides: Effects of enzyme-assisted Aspergillus niger solid-state fermentation on its structural features, simulated gastrointestinal digestion, and prebiotic activity

Adlay seed bran, typically discarded or used as animal feed, represents a significant resource waste. This study investigates the structural and physicochemical properties, in vitro digestive behavior, and fecal fermentation profiles of adlay seed bran polysaccharides (ASBPs) prepared using different methods. These methods include hot water extraction, Aspergillus niger solid-state fermentation (SSF), and enzyme-assisted SSF with β-glucosidase, cellulase, and xylanase, referred to as ASBP, ASBP-F, ASBP-GF, ASBP-CF, and ASBP-XF, respectively. Results showed that enzyme-assisted SSF with A. niger improved extraction efficiency and uniformity of ASBPs, increasing total neutral sugars, uronic acids, mannose, and galactose while reducing glucose content, molecular weight, and particle size. ASBP-CF had the best extraction rate, sugar content, lowest molecular weight, finest uniformity, and smallest particle size. In simulated digestion tests, all ASBP variants were stable in stomach and small intestine conditions but degradable by human fecal microbiota, showing varying fermentability levels. ASBPs increased Bacteroidetes populations, inhibited Proteobacteria growth, and enhanced short-chain fatty acid (SCFAs) production, with ASBP-CF showing the highest fermentability and prebiotic efficacy. ASBP-CF was particularly effective in promoting beneficial bacteria like Bacteroides and restraining harmful bacteria such as Escherichia_Shigella, producing more SCFAs during fermentation. These findings suggest that ASBP-CF has potential as a dietary supplement to improve gut health, presenting a high-value utilization strategy for adlay seed bran.

Extraction, Structural Characterization, and Physicochemical and Biological Properties of Water-Soluble Polysaccharides from Adlay Bran

Adlay bran, often discarded or used as animal feed, holds untapped potential. This study explores the beneficial properties of water-soluble polysaccharides (ABPs), extracted using a hot water method, with the aim of transforming what is commonly regarded as waste into a valuable resource. The response surface methodology (RSM) was employed to fine-tune the extraction parameters, establishing conditions at 80.0 °C, 2.5 h, and a water-to-material ratio of 31.6 mL/g. Structural studies showed that ABPs consist of different monosaccharides, including rhamnose, arabinose, glucosamine, glucose, galactose, xylose, mannose, and glucuronic acid, with respective molar ratios of 2.12%, 2.40%, 0.52%, 77.12%, 7.94%, 3.51%, 2.55%, and 3.82%. The primary component of these polysaccharides has a molecular weight averaging 12.88 kDa. The polysaccharides feature eight distinct linkage types: →3,4)-Rhap-(1→ at 5.52%, →4)-Glcp-(1→ at 25.64%, Glcp-(1→ at 9.70%, →3,4)-Glcp-(1→ at 19.11%, →4)-Xylp-(1→ at 7.05%, →3)-Glcp-(1→ at 13.23%, →3,4)-Galp-(1→ at 9.26%), and →4,6)-Gclp-(1→ at 12.49%. The semi-crystalline properties of ABPs and their shear-thinning characteristics were validated by X-ray diffraction and rheology tests. In vitro assays highlighted the strong antioxidant activities of ABPs, as evidenced by DPPH and ABTS hydroxyl radical scavenging tests, along with significant metal chelating and reducing powers. Additionally, ABPs showed significant inhibition of α-glucosidase and α-amylase, making them attractive as versatile additives or as agents with antioxidant and blood-sugar-lowering properties in both the food and pharmaceutical sectors. These findings support the utilization of adlay bran for higher-value applications, harnessing its bioactive components for health-related benefits.

Effects of protein morphological structures on the cereal processing, sensorial property and starch digestion: a review

In cereals, the protein body and protein matrix are usually two morphological protein structures. However, processing treatments can affect protein structures, change protein bodies into the matrix, or induce a change in the matrix structure; therefore, the processing-induced matrix was listed as the third morphological structure of the protein. Previous research on the effect of proteins was mainly based on protein content and composition, but these studies arrived at different conclusions. Studying the effect of protein morphological structures on sensorial property and starch digestion can provide a theoretical basis for selecting cultivars with high sensorial property and help produce low-glycemic index foods for people with diabetes, controlling their postprandial blood sugar. This study aimed to review the distribution and structure of protein bodies, protein matrices, and processing-induced matrices, as well as their influence on cereal sensorial property and starch digestion. Therefore, we determined the protein morphological structures in different cereal cultivars and summarized its impact. Protein bodies mainly have steric stabilization effects on starch gelatinization, whereas the protein matrix serves as a physical barrier surrounding the starch to inhibit water absorption and α-amylase. Processing can change protein morphological structures, enabling protein bodies to act as a physical matrix barrier.

Physicochemical and nutritional profiles of wild adlay (Coix lacryma-jobi Linn) accessions by GC, FTIR, and spectrophotometer

Purpose of current study was to determine physicochemical, triglyceride composition, and functional groups of wild adlay accessions (brown, black, yellow, grey, green, off white, and purple) to find out its scope as cereal crop. Triglycerides, minerals and functional groups were determined through Gas chromatography, spectrophotometer and Fourier Transform Infrared (FTIR) spectrophotometer respectively. Results revealed variation among bulk densities, specific densities, percent empty spaces, and corresponding grain counts per 10 g of sample are useful in distinguishing brown, black, yellow, grey, green, off white, and purple wild adlay accessions. Specific density and grain count per 10 g sample was significantly related. No statistical relationship exists among the pronounced physical characteristics. Brown adlay expressed the highest protein, fat, and fiber contents 15.82%, 4.76% and 2.37% respectively. Protein, fat, ash, and fiber percent contents were found comparable to cultivated adlay. Spectrophotometric analysis revealed macro elements including phosphorus, potassium, calcium, and sodium in the range 0.3% - 2.2% and micro elements boron, iron, copper, zinc, and manganese in the range 1.6 mg/kg - 20.8 mg/kg. Gas chromatography showed polyunsaturated fatty acids (PUFA) constitute the primary fraction (39% ± 7.2) of wild adlay triglycerides. Linoleic and palmitic acids were present as prominent fatty acids, 43.5% ±1.4 and 26.3% ±1.4 respectively. Infra-red frequencies distinguished functional groups in narrow band and fingerprint region of protein in association with out of plane region leading to structural differences among adlay accessions. Comparison of major distinguishing vibrational frequencies among different flours indicated black adlay containing highest functional groups appeared promising for varietal development.

Effect of endogenous protein and lipid removal on the physicochemical and digestion properties of sand rice (Agriophyllum squarrosum) flour

The study investigated the effect of removing protein and/or lipid on the physicochemical characteristics and digestibility of sand rice flour (SRF). Morphological images showed that protein removal had a greater impact on exposing starch granules, while lipids acted as an adhesive. The treatment altered starch content in SRF samples, leading to increased starch crystallinity, denser semi-crystalline region, lower onset gelatinization temperature (To), higher peak viscosity and gelatinization enthalpy (ΔH), where Protein removal showed a more pronounced effect on altering physicochemical properties compared to lipid removal. The research revealed a positive correlation between rapidly digestible starch (RDS), maximum degree of starch hydrolysis (C∞), digestion rate constant (k) values and 1047/1022 cm-1 ratio, showing a strong connection between short-range structure and starch digestibility. The presence of endogenous proteins and lipids in SRF hinder digestion by restricting starch swelling and gelatinization, and physically obstructing enzyme-starch interaction. Lipids had a greater impact on starch digestibility than proteins, possibly due to their higher efficacy in reducing digestibility, higher lipid content with greater potential to form starch-lipid complexes. This study provides valuable insights into the interaction between starch and proteins/lipids in the sand rice seed matrix, enhancing its applicability in functional and nutritional food products.

Development of a Reliable ic-ELISA with a Robust Antimatrix Interference Capability Based on QuEChERS Technology for the Rapid Detection of Zearalenone in Edible and Medical Coix Seeds and Subsequent Risk Assessments

Indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) is an ideal immunoassay method for large-scale screenings to detect mycotoxin contaminants. However, the matrix effect of complicated samples has always been challenging when performing immunoassays, as it leads to false-positive or negative results. In this study, convenient QuEChERS technology combined with optimizing the dilution solvent was ingeniously used to eliminate interference from the sample matrix to greatly improve the detection accuracy, and reliable ic-ELISAs for the two official tolerance levels of 60 and 500 μg/kg were developed to screen zearalenone (ZEN) in edible and medical coix seeds without any further correction. Then, the 122 batches of coix seeds were determined, and the positive rate was up to 97.54%. The contaminated distribution was further analyzed, and risk assessment was subsequently performed for its edible and medical purposes. The findings indicated that consumption of coix seeds with higher ZEN contamination levels may cause adverse health effects for both medical and edible consumption in the adult population; even under the condition of average contamination level, ZEN from coix seeds was the more prominent contributor to the total risk compared to other sources when used as food; thus, effective prevention and control should be an essential topic in the future.