In this study, the quality changes of reasonably well-milled rice (RW-rice) under different storage methods were analyzed from several aspects such as antioxidant capacity and texture. Meanwhile, headspace-solid phase microextraction coupled with gas chromatography-mass spectrometry and transcriptomics techniques were used to analyze volatile compounds and metabolic pathways, respectively, in order to select the optimal storage method. The findings indicated that N₂-filled tinplate cans better maintained the storage quality and delayed the deterioration of RW-rice. In addition, 1-octen-3-ol, 2-pentylfuran and benzaldehyde were the major contributors to RW-rice aroma. The study also discovered that there was a significant correlation between antioxidant capacity, color, texture properties and key flavor compounds. Notably, storage in N₂-filled tinplate cans promoted phenylalanine, tyrosine and tryptophan biosynthesis and phenylpropanoid biosynthesis in RW-rice, and contributed to the synthesis of benzaldehyde, phenylethyl alcohol and phenol. In summary, this research provides fresh insights into the deterioration mechanism of RW-rice stored in N₂-filled tinplate cans, establishing a theoretical foundation for RW-rice storage.

To obtain a full understanding the quality and microbial characteristics of soybean paste made from a mixture of soybean and broomcorn millet flour, its physicochemical properties (amino nitrogen and nitrite), and total phenols (TP), γ-aminobutyric acid (GABA), free amino acids (FAAs), volatile compounds, and microbial community composition were investigated. The results showed that the amino nitrogen content increased to 0.71%, and the nitrite content decreased to within the standard range (1.37 mg/kg). The contents of TP, key FAAs and volatile compounds increased significantly during the fermentation process. The core microbial communities included Enterobacter, Pseudomonas, Stenotrophomonas, Aspergillus, and Alternaria. The results of correlation analysis confirmed that bacteria (Bacillus, Knoellia, and Blastococcus) and fungi (Epicoccum and Saccharomyces) played a significant role in the bioactivity changes and flavor generation in soybean paste. This study will be of great significance for understanding the quality and flavor of novel soybean paste made with cereal flour as an additive.

In this study, the structural evolution of mung bean globular amyloid fibrils (MBGFs) during the formation process was investigated with different acid-heat treatment times, and the emulsification properties of MBGFs were also explored at each stage of the formation process. The results showed that the subunits of mung bean globulin (MBG) were gradually degraded and hydrolyzed into fibrous structure units mainly composed of small peptides during 0–12 h of heating. And a large number of β-sheet structures were produced, and its relative content increased from an initial level of (18.28 ± 0.75)% to (53.61 ± 1.15)% over the 12 heating period. Enhanced fluorescence intensity was recorded after combination with thioflavin-T. Morphologically, MBGFs gradually became elongated and pliable, and oriented fibril aggregation occurred in the heating process. Between 16 and 24 h, the structure of mature MBGFs gradually was dissociated and the structural characteristics of the fibers were destroyed. The emulsification activity, emulsion stability, protein adsorption rate and interfacial protein content of MBGF were significantly improved compared with those of MBG. MBGFs formed by acid-heat treatment for 4 h had the best emulsification properties. Oil droplets in the MBGF emulsion were small in size, uniformly and orderly distributed, and the emulsion had the highest apparent viscosity and showed an elastic gel structure. In conclusion, different acid-heat treatment times had significant effects on the structure and emulsification properties of MBGFs, and MBGFs had better emulsification properties than MBG. This study will provide theoretical support for clarifying the formation of MBGFs and ideas for the development of highly efficient food-grade emulsifiers.

In this study, black soybean protein was enzymatically hydrolyzed to prepare xanthine oxidase (XOD) inhibitory peptide. Based on XOD inhibitory activity and degree of hydrolysis (DH), various proteases were screened, and the hydrolysis parameters were optimized. Furthermore, the protein hydrolysate was fractionated by membrane separation into several fractions. The molecular mass ranges of the resulting fractions were determined based on XOD inhibitory activity, and their amino acid composition, molecular mass distribution, peptide sequences, activity and stability were analyzed. The results showed that the optimum enzymatic hydrolysis conditions were as follows: alkaline protease dosage of 1.5%, hydrolysis time of 4 h, temperature of 50 ℃, pH 9.0, and substrate concentration of 3%. Under the optimized conditions, the XOD inhibition rate and DH of the protein hydrolysate were 73.61% and 21.29%, respectively. The XOD inhibitory activity of F3, obtained from ultrafiltration of the hydrolysate, was the highest (with a half-maximal inhibitory concentration (IC₅₀) of 8.76 mg/mL), with the molecular mass ≤ 1500 Da. In F3, hydrophobic and basic amino acids accounted for 56.66% and 20.16% of the total amino acids, respectively. This fraction had good stability under high-temperature treatment, simulated gastric and trypsin digestion. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) identified 18 peptides in F3, with an average molecular mass of approximately 500–1400 Da. In these peptides, hydrophobic amino acids at the N-terminus and C-terminus accounted for 44.86% and 33.14%, respectively, and basic amino acids accounted for 33.57% and 39.29% of the total amino acid residues, respectively. The results of this study provide a theoretical basis for the high value utilization of black bean protein.

To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides (SBOS) extracted from defatted soybean meal, the changes in monosaccharide composition and molecular mass were analyzed. Subsequently, the effect of SBOS on microbial community structure and metabolites was studied by 16S rRNA gene sequencing and untargeted metabolomics based on liquid chromatography-mass spectrometry. Results showed that SBOS was not easily enzymolyzed during simulated digestion and could reach the large intestine through the digestive system. The significant decrease in the molecular mass of SBOS after in vitro fermentation indicated its utilization by the gut microbiota, which increased the contents of short-chain fatty acids and lactic acid, thereby reducing the pH of the fermentation broth. Moreover, the core community was found to consist of Blautia, Lactobacillaceae, and Pediococcus. SBOS up-regulated beneficial differential metabolites such as myo-inositol, lactose, and glucose, which were closely related to galactose, amino sugar, and nucleotide sugar metabolism. This study will provide a reference for exploring the relationship between the gut microbiota and the metabolites of SBOS, and provide a basis for the development and application of SBOS as an ingredient for functional products.

In maize breeding, limitations on sampling quantity and associated costs for measuring maize grain moisture during filling are imposed by factors like the planting area of new varieties, maize plant density, effective experimental spikes, and other conditions. However, the conventional method of detecting moisture content in maize grains is slow, damages seeds, and necessitates many sample sets, particularly for high moisture content determination. Thus, a strong demand exists for a non-destructive quantitative analysis model of maize moisture content using a small sample set during grain filling. The Bayes-Merged-Bootstrap (BMB) sample optimization method, which built upon the Bayes-Bootstrap sampling method and the concept of merging, was proposed. A critical concern in dealing with small samples is the relationship between data distribution, minimum sample value, and sample size, which has been thoroughly analyzed. Compared to the Bayes-Bootstrap sample selection method, the BMB method offers distinct advantages in the optimized selection of small samples for non-destructive detection. The quantitative analysis model for maize grain moisture content was established based on the support vector machine regression. Results demonstrate that when the optimal resampling size is 1000 times or more than the original sample size using the BMB method, the model exhibits strong predictive capabilities, with a determination coefficient (R²)>0.989 and a relative prediction determination (RPD)>2.47. The results of the 3 varieties experiment demonstrate the generality of the model. Therefore, it can be applied effectively in practical maize breeding and determining grain moisture content during maize machine harvesting.

To enrich the flavor and nutritional efficacy of soymilk powder, this study investigated the effects of adding different ratios of pea peptides on the quality, nutrition and flavor of soymilk powder. The reconstitutability of soymilk powder was examined based on solubility and caking rate, and its in vitro bioactive functions were evaluated in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and cholesterol scavenging capacity. The changes in the structural properties and flavor quality of soymilk powder caused by addition of pea peptides were explored by Fourier transform infrared (FTIR) spectroscopy, nanoparticle size analyzer, confocal laser scanning microscopy (CLSM), and headspace solid phase microextraction (HS-SPME)-gas chromatography-mass spectrometry (GC-MS). The results showed that the addition of 30%pea peptides to soymilk powder increased the protein content by 13.05% and solubility by 11.23%, decreased the caking rate by 4.20%, enhanced the DPPH radical and cholesterol scavenging capacity by 19.84% and 21.25%, respectively, and significantly improved the reconstitutability in hot water at 70 ℃. The structural analysis results revealed that pea peptide addition altered the secondary structure of proteins, reduced the average particle size, and resulted in more uniform particle size distribution in reconstituted soymilk, thereby improving the solubility of soymilk powder. Additionally, pea peptide addition changed the concentrations of the key flavor components geranylacetone, myristic acid, 3-methylthiopropanal, 2-methylpyrazine and 2,5-dimethylpyrazine in reconstituted soymilk, while decreasing the concentrations of off-flavor substances, such as hexanal, trans-2-nonenal, nonanal, n-hexanol, 1-octen-3-ol and naphthalene.