This study aimed to investigate the effects of a nitrite composite substitute (NSCS) composed of several natural substances (0.03% monascus red, 0.04% Nisin, and 0.03% rosemary) on the eating quality, total bacterial count, nitrite residue, and other indices of yak meat sausages during storage (1, 3, 5, 7, and 9 d), and to clarify the substitution effect of NSCS on nitrite in minced meat products. Results showed that NSCS exerted positive effects on improving the eating quality of yak meat sausages, reducing the total bacterial count and nitrite residues by substituting nitrite. Specifically, on day 9, the NSCS-treated group exhibited the highest water-holding capacity (86.1%), which was 15.5% higher than that of the nitrite-treated group (P<0.05). The cooking loss rate of the NSCS-treated group was significantly lower than that of the nitrite-treated group (P<0.05), and also significantly lower than that of the control group except on day 7 (P<0.05). During the storage period of 1~9 d, there was no significant difference in the total bacterial count between the NSCS group and the nitrite group, and both were significantly lower than that of the control group (P<0.05). On day 1, the nitrite residue in the nitrite-treated group reached the maximum of 28.3 mg/kg, which was significantly higher than those in the NSCS-treated group and the control group (P<0.05). On day 9, the nitrite residue in the nitrite-treated group dropped to the minimum of 11.2 mg/kg. Meanwhile, there was no significant difference in nitrite residue between the NSCS-treated group and the control group. In conclusion, NSCS can replace nitrite to a certain extent in the processing of yak meat sausages. This finding provides important reference significance for the development of green and organic yak meat products, and also offers theoretical references for research on nitrite substitutes in other minced meat products.

In this study, soaking solutions prepared from rosemary, clove, and mint extracts were used for the pretreatment of Undaria pinnatifida. Combined with electronic sensory analysis and gas chromatography-mass spectrometry (GC-MS) techniques, the effects of different extract addition amounts, solid-liquid ratios, and soaking times on the quality and deodorization effect of Undaria pinnatifida were analyzed, and the optimal pretreatment process was screened out. The results showed that the optimal deodorization process was as follows: extract concentration of 4 g/L, solid-liquid ratio of 1:4 (g/mL), and soaking time of 40 min. Mint and rosemary extracts exhibited color-protecting effects (ΔE<2, moderate color difference), while clove extract could improve the texture properties of Undaria pinnatifida (P<0.05). The electronic nose results indicated that the contents of nitrogen oxides and inorganic sulfides in Undaria pinnatifida soaked with clove and rosemary extracts were the highest. A total of 52 volatile compounds were identified in Undaria pinnatifida by GC-MS, among which 6 were key flavor substances. Rosemary extract reduced the contents of fishy substances such as hexanal, 1-pentanol, and 2-heptanol in Undaria pinnatifida, and increased the contents of floral and fruity compounds including 3-octanone, β-ionone, 1-octen-3-ol, eugenol, eucalyptol, and 4-allylanisole. This study provides a theoretical basis for deodorization and quality preservation during the deep processing of Undaria pinnatifida.

To explore the effect of berberine hydrochloride on the proliferation and differentiation of chicken myoblasts. In this study, the effects of berberine hydrochloride on cell proliferation and differentiation were detected by CCK-8 assay, EdU staining and Desmin immunofluorescence staining. The gene expression levels of myogenic factor 5 (MYF5) and myogenic differentiation 1 (MYOD) were determined by real-time quantitative PCR (RT-qPCR). The effects of berberine hydrochloride on the gene expression profiles of chicken myoblasts were also investigated by RNA sequencing analysis. The results showed that berberine hydrochloride treatment significantly promoted the proliferation of chicken myoblasts while inhibiting the expression of MYOD (P<0.01) and MYF5 (P<0.05). Desmin staining showed slightly weaker fluorescence signals in the cytoplasm of the experimental group than that of the control group, indicating that berberine hydrochloride inhibited the differentiation of chicken myoblasts to a certain extent. In addition, Gene Ontology enrichment analysis (GO) showed that the differential genes were mainly enriched in extracellular space and matrix, cell adhesion, and cell migration regulation after berberine hydrochloride treatment; Kyoto Encyclopedia of Genes and Genomes enrichment analysis (KEGG) showed that the differential genes were mainly enriched in tyrosine metabolism, TGF-β signaling pathway, MAPK signaling pathway and cell adhesion molecule-related signaling pathway. The RT-qPCR results showed that in the TGF-β pathway, the expression of Inhibitor of DNA Binding 1 (ID1) and Paired-like Homeodomain Transcription Factor 2 (PITX2) was upregulated, while Follistatin (FST) was downregulated. In the MAPK pathway, the pro-proliferative genes Insulin-like Growth Factor 2 (IGF2), Fibroblast Growth Factor 7 (FGF7), FBJ Murine Osteosarcoma Viral Oncogene Homolog (FOS), Fms-related Tyrosine Kinase 1 (FLT1), and MAPK-activated Protein Kinase 3 (MAPKAPK3) were all upregulated, whereas the calcium channel gene Calcium Voltage-gated Channel Subunit Alpha1 E (CACNA1E) was downregulated. These findings suggested that berberine hydrochloride might synergistically regulate the proliferation-differentiation balance of myoblasts through the interaction between the TGF-β and MAPK signaling pathways. In this study, we found that berberine hydrochloride promoted the proliferation of chicken myoblasts and analyzed the molecular mechanism and provided theoretical support for the efficient culture of chicken myoblasts in vitro.

Taking gray Sufu inoculated with Mucor UV-M2 as the research object, the changes of volatile metabolites, microorganisms and their correlation during fermentation of grag Sufu were explored. In this study, the quality of the fermentation process was comprehensively evaluated using physicochemical indexes and sensory assessment methods. The results confirmed that the fermentation process reached an optimal state after 40 days. Non-targeted volatile metabolomics analysis revealed significant variations in metabolites at different fermentation stages. Based on the odor threshold, 18 compounds with an odor activity value (OAV)>1 were evaluated. Among them, 11 compounds contributed to the aroma profile, including esters, aldehydes, and ketones, while 7 compounds were associated with unpleasant odors, mainly sulfur-containing compounds. Microbiological analysis demonstrated that the diversity of fungi and bacteria decreased significantly as the fermentation progressed. Through Spearman correlation analysis, it was found that the bacteria Tetragenococcus and Halanaerobium exhibited positive correlations with most volatile compounds with OAV>1, whereas Acinetobacter showed negative correlations with these compounds. Among fungi, Mortierella, Aspergillus, Malassezia, Botrytis, Penicillium, and Sagenomella were positively correlated with most of the compounds, while Actinomucor and Candida showed negative correlations. Furthermore, the results of redundancy analysis (RDA) indicated that, among bacteria, Weissella and other genera were positively correlated with salt content. In the fungal community, amino-acid nitrogen was positively correlated with Mortierella, salt content was positively correlated with Actinomucor, and pH was positively correlated with Kodamaea. These findings suggest that the quality indexes of gray Sufu are positively associated with the core microbial flora. Overall, the above results indicate a significant correlation between the aroma characteristics and the microbial community at different stages during the fermentation of gray Sufu. This study provides valuable references for enhancing the flavor quality of gray Sufu through microbial regulation techniques.

In order to solve the common problems of commercial sugarcane wine, such as light fruit aroma and thin wine body, this study aimed to investigate the effects of passion fruit and Liu Pao tea as flavor enhancers on the aromatic components of sugarcane fruit wine. The aromatic components of three sample groups were qualitatively and quantitatively analyzed using headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and gas chromatography-ion mobility spectrometry (GC-IMS). The results showed that a total of 98 volatile compounds were detected, with 71 in the sugarcane fruit wine group, 83 in the Liu Pao tea group, and 80 in the passion fruit group. Odor activity value (OAV) analysis revealed that 14 compounds exhibited an OAV greater than 1, while 15 compounds showed a relative odor activity value (ROAV) greater than 1. Orthogonal partial least squares discriminant analysis (OPLS-DA) identified 25 key flavor compounds (VIP>1). Among these, γ-terpinene and 3-hydroxy-2-butanone contributed grassy and citrus aromas to the Liu Pao tea group, whereas damascenone and β-ionone enhanced fruity and floral aromas in the passion fruit group. Both passion fruit and Liu Pao tea were found to effectively enrich the aromatic composition of sugarcane fruit wine, with each enhancing the aroma profile in distinct ways. Comprehensive aromatic quality analysis indicated that passion fruit exhibited superior aromatic enhancement effects and was determined to be more suitable as an aromatic enhancer for sugarcane fruit wine.

In order to investigate the effects of postharvest ambient temperature on the physical characteristics and volatile components of jasmine flowers, J. sambac 'Shuangban-moli' flowers buds was employed as experimental materials in this study. The physical characteristics of jasmine flowers (bulk density, moisture content, floral temperature, jasmine pile temperature, CO₂ concentration, and O₂ concentration) were examined under different postharvest ambient temperatures (29±2, 35±2, and 41±2 ℃, humidity: 85%±3%). Automated thermal desorption-gas chromatography-mass spectrometry (ATD-GC-MS) was employed to analyze the volatile components of jasmine flowers under different postharvest ambient temperatures. The results showed that the physiological activities of jasmine flowers were suppressed, and the blooming process was delayed at the postharvest ambient temperature 29 ℃. In contrast, it was more conducive to their fragrance release, and jasmine flowers exhibited the highest degree of blooming, the peak flowering condition, and the faster blooming process at the postharvest ambient temperature 35 ℃. Sensory evaluation also indicated that jasmine flowers had a rich aroma and pure white color at the postharvest ambient temperature 35 ℃. A total of 102 volatile components were identified from jasmine flowers maintained at different postharvest ambient temperatures, including 28 esters, 19 terpenes, 15 alcohols, 11 alkanes, 7 aromatic hydrocarbons, 4 halogenated hydrocarbons, 4 aldehydes, 2 cyclic hydrocarbons (non-aromatic), 2 ethers, 2 ketones, 2 phenols, 2 acids, and 4 other substances. Jasmine flowers exhibited significantly higher relative abundance of some volatile components during the flower starts blooming stage, flower fully blooming stage, and flower starts senescence stage at the postharvest ambient temperature 35 ℃ compared to other temperatures (P<0.05). As the key contributors to the "fresh floral scent" of jasmine flowers, such as α-farnesene and trans-caryophyllene etc terpenes with floral and fruity fragrances had significantly higher relative content during the flower starts blooming stage and flower fully blooming stage at the postharvest ambient temperature 35 ℃ than other temperatures (P<0.05). In summary, it was beneficial for jasmine flower blooming and fragrance release at the postharvest ambient temperature 35 ℃.

The study examined the effects of oxygen, light, temperature, non-covalent bonds, and metal ions on the precipitation amount, as well as the protein, starch, pectin, and tannin content in the supernatant of Sichuan bran vinegar, to determine the key factors influencing turbidity reversion. Using transmittance as the response value, the clarification conditions were optimized via single-factor experiments combined with response surface methodology (RSM). The results indicated that oxygen and temperature were critical factors promoting turbidity reversion, with significantly shorter turbidity reversion time under aerobic conditions compared to anaerobic conditions, and higher temperature further accelerating the process. Investigations into non-covalent interactions revealed that the addition of NaCl and guanidine hydrochloride disrupted electrostatic forces and hydrogen bonds, significantly reducing precipitation while increasing the protein, starch, pectin, and tannin content in the supernatant. This suggested that electrostatic interactions and hydrogen bonds facilitated macromolecular complexation and subsequent precipitation. Metal ions (Fe³⁺, Ca²⁺) had no significant effect on turbidity reversion. The optimal clarification conditions determined by single-factor and RSM optimization were: acidic protease dosage of 2.10 g/L, treatment time of 2.20 h, treatment temperature of 30 °C, and standing time of 2 h, achieving a transmittance of 85.75%±0.24%. This study provides a data foundation for understanding the mechanism of turbidity reversion and offers practical solutions for industrial production of Sichuan bran vinegar.

This study aimed to investigate the hydrolysis characteristics of walnut protein hydrolysates and identify low-bitterness antioxidant peptides derived from them. Four proteases—papain, chymotrypsin, alkaline protease, and acid protease—were used to hydrolyze walnut proteins, and the degree of hydrolysis of the resulting hydrolysates was evaluated. The study focused on alkaline protease treatment at varying hydrolysis durations (2, 4, and 6 h), examining the degree of hydrolysis, yield, molecular weight distribution, bitterness response value, and amino acid composition of the hydrolysates. Low-bitterness antioxidant peptides were subsequently identified from the hydrolysates with reduced bitterness. Results showed that alkaline protease effectively hydrolyzed walnut proteins, achieving the highest degree of hydrolysis (55.60%±0.46%) and yield (48.86%±0.99%) after 6 h. As hydrolysis time increased, the proportion of high molecular weight components decreased, while that of low molecular weight components increased. The hydrolysate obtained after 4 h of hydrolysis exhibited the lowest bitterness response value, characterized by minimal proportions of hydrophobic and bitter amino acids in its composition, and displayed significant antioxidant activity. Two non-bitter peptide sequences, YWL and FFL, were identified from the 4 h hydrolysate. Molecular docking analysis indicated that these peptides could effectively bind to the Keap1 protein through hydrogen bonding and hydrophobic interactions, thereby exerting antioxidant effects. This study provides a theoretical foundation for the development of high-quality, low-bitterness walnut-derived antioxidant peptides, offering valuable insights for their potential applications in functional foods and nutraceuticals.

This study investigated the differences in physicochemical properties and volatile aroma components between fresh Hotan Red grapes (GR) and their dried products including dried raisins without drying agent pretreatment (NDAR) and drying agent-pretreated raisins (DAR). The results indicated that the color of raisins darkened after drying, with an increase in red-yellow values (a^*, b^*). The contents of reducing sugars, titratable acids, and ascorbic acid increased significantly. However, drying agent pretreatment reduced the lightness (L^*) and further enhanced the red-yellow values (a^*, b^*) of raisins. Additionally, it increased the reducing sugar content while decreasing titratable acidity and ascorbic acid levels. Electronic nose (E-nose) radar fingerprint plots exhibited distinct response patterns. Through qualitative and quantitative analysis of volatile compounds, 99, 109, and 108 volatile compounds were detected in GR, NDAR, and DAR, respectively. The dominant volatile classes were alcohols (48.45%) in GR, aldehydes (58.46%) in NDAR, and ketones (45.00%) in DAR. Compared to NDAR, drying agent pretreatment led to the degradation and disappearance of D-limonene, a 2.88% reduction inthe relative content of aldehydes and ketones, affecting the concentration of characteristic aroma components in raisins. Based on OAV (Odor Activity Value)>1, pretreatment with drying agents weakened the concentrations of furfural, 5-methylfurfural, and nine other key aroma compounds. Furthermore, sixteen key aroma compounds were screened using ROAV (Relative Odor Activity Value)≥1, and three critical compounds: decanal, E-2-nonenal, and ethyl 2-methylbutyrate were identified (VIP>1), playing a crucial role in distinguishing GR, NDAR, and DAR. While GR exhibited a significantly different aroma profile compared to NDAR and DAR, the overall aroma characteristics of NDAR and DAR were similar, but NDAR had more pronounced fruity and sweet aromas than DAR. This study elucidates the differences in physicochemical properties and volatile aroma compounds between Hotan Red grapes, drying agent pretreatment and drying agent-pretreated raisins, which provides data support and a theoretical foundation for optimizing subsequent drying processes and enhancing the flavor characteristics in Hotan Red raisin production.

In order to improve the functional properties of pea protein isolate (PPI), such as solubility, emulsification, foaming capacity, and broaden its application in the food industry, in this study, PPI was selectively extracted using ammonium sulfate precipitation, and was covalently grafted with chitosan oligosaccharides (COS), carrageenan oligosaccharides (CAS), alginate oligosaccharides (AOS), and agaric oligosaccharides (AGS) at an oligosaccharide-to-protein ratio of 20% using cold plasma (CP) induction. The effects of this non-thermal covalent grafting with marine oligosaccharides on the solubility, thermal stability, foaming capacity, and emulsifying properties of PPI were investigated. The results showed that CP treatment induced effective and rapid covalent grafting between PPI and marine oligosaccharides. The highest grafting rate (17.89%) was observed in the PPI-COS combination. In terms of mixtures, the solubility of the covalent complexes was significantly improved (P<0.05) after CP induction relative to those without CP treatment, in the order of AGS/PPI-CP>COS/PPI-CP>CAS/PPI-CP>AOS/PPI-CP. Among them, AGS/PPI-CP showed the highest solubility (0.775 mg/mL), while COS/PPI-CP exhibited the greatest foaming capacity (146.67%), emulsifying activity (123.21%), and emulsion stability (37.73%). These enhancements significantly improved the interfacial adsorption of PPI, contributing to greater stability at both air-water and oil-water interfaces. In conclusion, non-thermal covalent grafting of marine oligosaccharides with CP was effective in enhancing the functional properties of PPI. These findings provide valuable guidance for the development of functional pea protein-based food products and related applications.