This study developed a high-stability indicator film containing a roselle (Hibiscus sabdariffa) anthocyanin extract (RAE)-oxalic acid (OA) co-pigment indicator (RAO), investigated the stability of the RAO indicator and its effects on the structure and performance of the indicator film, and applied the film to monitor the freshness of channel catfish (Ictalurus punctatus). The results showed that the stability of the RAO indicator improved compared with single RAE indicator. Moreover, the film with the RAO indicator showed enhanced performance. The tensile strength and elongation at break of the indicator film increased from 16.10 MPa and 280.95% to 17.81 MPa and 349.45%, respectively. Its moisture content and water solubility decreased from 19.10% and 42.71% to 13.98% and 34.69%, respectively. Under conditions of 4 ℃, 45% humidity, and no light exposure, the RAO indicator film could be stored for up to 82 days (ΔE<5). When used for monitoring the freshness of channel catfish at 4 ℃, the indicator film changed from rose-red to yellow-gray as the fish spoiled, demonstrating its accuracy in monitoring the spoilage process and its great potential for freshness monitoring applications.

Thirteen commercially available fermented rice cakes were selected to assess their quality. We evaluated the color, specific volume, texture, and volatile flavor compounds. The differences and correlations among these indicators were also investigated. Furthermore, a comprehensive evaluation was conducted using principal component analysis (PCA) to identify key indices representing overall quality. The results showed that 13 commercially available fermented rice cakes exhibited variations in specific volume, color, texture, types and contents of volatile flavor substances, and sensory characteristics. In the correlation analysis between specific volume, color index, and sensory evaluation indice: rice white color was significantly negatively correlated with b^* value (P<0.05), and extremely significantly positively correlated with L^* value and specific volume (P<0.01). In the correlation analysis between texture and sensory evaluation indices: moderate stickiness and uniform air pores were significantly correlated with adhesiveness, cohesiveness, springiness, gumminess, and chewiness (P<0.05). In the correlation analysis between flavor substances and sensory evaluation indices: isoamyl alcohol and phenylethanol were extremely significantly positively correlated with fermented flavor (P<0.01), and isoamyl alcohol was significantly positively correlated with cereal flavor (P<0.05). Through principal component analysis, four principal components were ultimately identified with a cumulative variance contribution rate of 91.166%, namely cohesiveness, viscosity, isoamyl alcohol content, and b^* value, which could serve as core quality indicators for fermented rice cake and characterize the overall quality characteristics of fermented rice cake.

This study employed response surface methodology to optimize the preparation process of phosphorylated chicory polysaccharide iron. It characterized the structure of the composite using Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Through simulated artificial gastrointestinal fluid digestion experiments, sucrase hydrolysis experiments, and mucin-binding capacity assays, the in vitro digestive characteristics of phosphorylated chicory polysaccharide iron were systematically analyzed. The results indicated that the optimal reaction conditions were a reaction time of 1.1 h, a reaction temperature of 64 ℃, and a pH of 10. Under these conditions, the iron content of the prepared phosphorylated chicory polysaccharide iron reached 26.97%±0.25%. Infrared spectroscopy of phosphorized chicory polysaccharide iron showed that the O-H and C=O groups in the phosphorized chicory polysaccharide coordinate with Fe³⁺. XPS confirmed that iron was introduced into the phosphorized polysaccharide in the trivalent state (Fe³⁺). SEM observation revealed that the composite morphology was a dense layered structure. In vitro gastrointestinal digestion results showed that the iron retention rate in gastric fluid was >97% after 24 hours, while in the simulated intestinal environment containing mucin and sucrase, 59% was released after 7 hours, with a cumulative release rate of 74.5%±0.5% after 24 hours. This study provides a theoretical basis for the high-value utilization of chicory polysaccharide resources and the development of polysaccharide iron supplements.

This study aimed to screen lactic acid bacteria (LAB) starters with high exopolysaccharides (EPS) production and to analyze their metabolic mechanisms. By assessing the EPS content in fermented skim milk co-cultured with nine laboratory-isolated EPS-producing LAB strains and commercial strains, the optimal starter (designated as the SW group) was identified as a composite of the laboratory-isolated Lactobacillus pentosus strain 15 and commercial strains. The EPS content and viscosity of skim milk fermented by the SW group were significantly (P<0.05) higher than those observed in the control group (S group). Through the integration of physicochemical analysis and LC-MS-based untargeted metabolomics, a total of 67 differential metabolites were identified, comprising 40 upregulated and 27 downregulated metabolites. Metabolic analysis indicated activation of the arginine biosynthesis pathway, as demonstrated by the upregulation of arginine and its precursor N-acetylglutamate-5-semialdehyde (NAGSA), alongside the downregulation of ornithine. Concurrently, the essential amino acid L-leucine was significantly upregulated. Organic acids, including 2-hydroxyhexanoic acid and hydrocinnamic acid, were found to modulate acidity, while the accumulation of benzoic acid contributed positively to shelf life extension. Furthermore, the upregulation of EPS synthesis precursors, specifically UDP-glucose and glucuronic acid, indicated that EPS synthesis predominantly involved glycosidic bond linkages among UDP-glucose, UDP-glucuronic acid, and GDP-mannose. Pathway enrichment analysis demonstrated that the cofactor biosynthesis pathway was the primary driver of the metabolic flux of EPS, with phenylalanine metabolism supplying essential nutrients and arginine biosynthesis facilitating the accumulation of functional components. Collectively, this study elucidated that the SW group enhanced nutritional value, antibacterial efficacy, and EPS production through multi-pathway metabolic regulation, thereby improving product texture and nutritional fortification. These findings offer a theoretical foundation for optimizing the quality of fermented foods.

The synergistic sterilization approach, which combines ultrasound with light, serves as an emerging green non-thermal sterilization technology that can effectively overcome the limitations of single technology application and markedly enhance antibacterial efficacy against foodborne pathogens. This enhancement in antibacterial efficacy is achieved through the direct synergistic effects of physical energy, without the need for exogenous sono/photosensitizers, and offers distinct advantages in terms of efficiency and environmental sustainability. This paper provides an overview of the current progress regarding the sterilization efficacy, mechanisms and practical applications of ultrasound, light (including UV light, blue light, infrared light and pulsed light) as well as their combination (primarily UV and blue light) on various microorganisms. Studies have demonstrated that ultrasound-light synergistic sterilization technology can not only remarkably improve the inactivation efficiency against foodborne pathogens, but also well preserve food product quality, thus providing a novel technical approach for food non-thermal sterilization. Future research should aim to further clarify the underlying synergistic mechanisms, expand the application scope, and accelerate the industrialization of this technology in the food sector. Overall, this paper provides a solid theoretical reference for the development and practical application of ultrasound-light synergistic sterilization technology.

This study focused on 14 edible fungi species—including Flammulina velutipes, Volvariella volvacea, Pleurotus ostreatus, Lyophyllum decastes, Agrocybe cylindracea, Lentinula edodes, Phallus indusiatus, etc. The ash content, protein content, crude polysaccharide content, amino acid composition and content of these edible fungi were systematically determined and analyzed. The volatile flavor substances were analyzed using HS-SPME/GC-MS, while the non-volatile flavor components such as free amino acids and 5'-nucleotides were also evaluated. The results showed that among the 14 edible fungi, the protein content of Agrocybe cylindracea was the highest, reaching 40.12 g/100 g, the ash content of Volvariella volvacea was significantly higher than that of other species (P<0.05). Agaricus subrufescens contained the highest polysaccharide content, reaching 11.77 g/100 g. More than 150 volatile substances were detected, with 60 kinds of volatile components being the richest in Tricholoma matsutake, and the key flavor substances of 14 edible fungi were mainly alcohols and aldehydes, including 1-octen-3-ol and isovaleraldehyde. The results of the determination of non-volatile substances showed that the total content of flavor nucleotides ranged widely, with the highest total content in Volvariella volvacea, followed by Agaricus bisporus, Tricholoma matsutake and Pleurotus ostreatus, with contents of 3.45, 2.50, 2.42 and 2.35 mg/g respectively, all categorized as medium levels. Agaricus bisporus had the highest Glu content, and its equivalent umami concentration (EUC) reached 1142.12 g MSG/100 g, belonging to the top umami grade. The main organic acid was succinic acid, which had the highest content in Volvariella volvacea, Agrocybe cylindracea and Agaricus subrufescens. Principal component analysis (PCA) and cluster analysis indicated that there were significant differences in the nutritional and flavor components of different edible fungi. Volvariella volvacea, Agrocybe cylindracea and Agaricus bisporus formed independent clusters due to their unique nutrient compositions. This study revealed the nutritional composition and flavor characteristics of different edible fungi through multi-faceted analysis, providing a theoretical basis for the development of high-value-added products and functional food design.

Starch, the primary source of carbohydrates in food, plays a crucial role in nutrition and health owing to its digestive properties and functional regulation and has been a subject of extensive research. Recently, researchers have non-covalently combined polyphenols with starch, which significantly altered its structural and functional properties. As research has progressed, it has been observed that polyphenols can form covalent bonds with starch chains through chemical agent coupling, free radical grafting, enzymatic catalysis, and acid-mediated pathways. Synthesized covalent conjugates exhibit superior structural and functional performance compared to non-covalent complexes and have become a focal point in the field of starch functional regulation, achieving significant advancements. This review aims to comprehensively summarize the binding mechanisms of starch and polyphenols through non-covalent and covalent interactions, compare them with non-covalent interaction mechanisms, and analyze the advantages of covalent interactions in binding modes and structural characteristics using structural characterization techniques. Additionally, by analyzing the functional characteristics of both, it emphasizes the significant advantages of covalent conjugates in thermal stability, digestion resistance, and antioxidant activity. Subsequent researchers can focus on starch-polyphenol covalent binding technology, which is expected to provide innovative approaches for the combination of natural ingredients and functional foods and contribute to the sustainable development of the food industry.