Chunlei Tan

Objective: This study aims to investigate the structural and functional characteristics of walnut protein hydrolysates (WPHs) with different molecular weights prepared using protease from Dregea sinensis Hemsl, as well as the anti-fatigue effects of low-molecular-weight walnut protein hydrolysates (LWPs) and their impact on the cecal microbiota and faecal metabolism of mice. Methods: The anti-fatigue activity of WPHs with different molecular weights was evaluated, and the LWPs were analyzed in a centralized manner. A 28-day gavage study was conducted to assess LWP’s anti-fatigue benefits in mice, supplemented by metabolomic analysis to explore its impact on metabolic pathways. Results: Our findings revealed that LWP significantly outperformed unhydrolyzed walnut protein (WP) in terms of water retention, lipid retention, emulsifying properties, and foaming capacity. Notably, differential protein expression associated with LWP highlighted pathways related to antioxidant activity. In vivo studies showed that LWP markedly enhanced glycogen storage in the muscles and liver of mice, while reducing serum levels of serum urea nitrogen, lactate dehydrogenase, blood lactic acid, and creatine kinase. Furthermore, the levels of Superoxide Dismutase and Glutathione were significantly elevated, alongside a reduction in Malondialdehyde, indicating that LWP’s anti-fatigue effect is closely linked to improved oxidative stress resistance. Additionally, LWP promoted beneficial increases in microbial populations such as Akkermansia, Alistipes, Eubacterium, and Muribaculum, which are associated with enhanced fatigue resistance. Metabolomic analysis indicated significant enrichment in glycerophospholipid metabolism and amino acid biosynthesis, identifying key metabolites including palmitoylethanolamide and 4-methyl-5-thiazoleethanol, both of which are integral to health maintenance. Conclusions: LWP demonstrates a robust anti-fatigue effect, supported by its accessibility, straightforward preparation, and eco-friendly characteristics. These attributes suggest that LWP has promising potential for inclusion in health products aimed at enhancing vitality and combating fatigue.

Non-dairy creamer is a class of microencapsulated powdered fats and oils that are widely used in the food industry. However, the oils used in it are hydrogenated vegetable oils, which contain large amounts of saturated fatty acids and are extremely harmful to the human body. This study investigated the effects of replacing hydrogenated vegetable oil with walnut oil to prepare walnut non-dairy creamer on lipid levels and intestinal microorganisms in mice. The results show that low-dose walnut non-dairy creamer significantly decreased the contents of TC and TG in serum and increased the content of HDL-C (p < 0.01). The contents of MDA, ALT, and AST were significantly decreased, while the content of SOD was increased (p < 0.01). The abundance of Firmicutes in the walnut non-dairy creamer group decreased, and the abundance of Bacteroidetes/Firmicutes (B/F) increased, which significantly increased the richness of Lactobacillus and Oscillospira (p < 0.01). Allobaculum richness was significantly decreased (p < 0.01). In conclusion, a low dose of walnut non-dairy creamer can effectively promote the metabolism of blood lipids in vivo, alleviate oxidative stress injury and lipid accumulation damage to mouse hepatocytes, and ameliorate the adverse effects of a high-fat diet on the intestinal microbiota of mice. This study provides a theoretical basis for the replacement of traditional non-dairy creamer and the research and development of walnut deep processing.

Milk fat is a premium nutritional health product, yet there is a lack of high-fat dairy products for daily consumption in the current market. This study investigated the influence of different milk fat contents on the physicochemical and textural properties of fermented milk. The research revealed that an increase in milkfat content significantly improved the water-holding capacity, syneresis, color, hardness, springiness, gumminess, and chewiness of fermented milk, while showing minimal changes in pH and total titratable acidity. Response surface analysis indicated that fermented milk with 25% milk fat, 2.5% inoculum, a fermentation time of 16 h, and a fermentation temperature of 30 °C exhibited the highest overall acceptability. Using GC-IMS technology, 36 volatile compounds were identified, with an increase in milk fat content leading to elevated levels of ketone compounds, and 14 compounds were defined as key aroma compounds (ROAV > 1). Electronic nose distinguished samples with different milk fat contents. The results demonstrate that an increase in milk fat content enhances the physicochemical and flavor attributes of fermented milk. This work provides theoretical references for the production and development of high-fat fermented milk.

In recent years, green and healthy foods have attracted much attention. Plant-based foods have become an alternative to animal-derived foods. In this study, we used walnut and purple rice as the primary raw materials to produce a fermented plant drink. The process included boiling, mixing, grinding, inoculation, fermentation, and sterilization. We then analyzed the similarities and differences between the resulting walnut and purple rice fermented plant drink and an unfermented walnut and purple rice plant drink, as well as dairy-based yoghurt, in terms of physical chemistry, flavor, and sensory characteristics. We also examined the similarities and differences between the walnut and purple rice fermented plant drink and room-temperature yoghurt. The study results revealed that the walnut and purple rice fermented plant drink exhibited greater viscosity than the walnut and purple rice unfermented plant drink and room-temperature yoghurt. Additionally, the former displayed enhanced stability and recovery ability. Notably, distinguishable differences were observed between the three samples in terms of the presence of unknown volatiles and the umami signal, as indicated by electronic nose/tongue and GC-IMS analyses. The umami flavor of the walnut and purple rice fermented plant drink surpasses that of room-temperature yoghurt, while its taste is less salty than that of the walnut and purple rice plant drink. Despite possessing a weaker aroma than dairy-based yogurt, it is more potent than the walnut and purple rice plant drink. Additionally, its relative abundance of olefins, ketones, and alcohols enhances its unique flavor profile, surpassing both other options. Based on sensory analysis, it can be deduced that walnut and purple rice fermented plant drink has the highest overall acceptance rate.

In recent years, green and healthy foods have attracted much attention. Plant-based foods have become a new trend to replace animal-derived foods. In this study, we used walnut and purple rice as the primary raw materials to produce yogurt. The process included boiling, mixing, grinding, inoculation, fermentation, and sterilization. We then analyzed the similarities and differences between the resulting walnut purple rice yogurt and unfermented walnut purple rice milk, as well as dairy-based yogurt, in terms of physical chemistry, flavor, and sensory characteristics. We also examined the similarities and differences between fermented walnut purple rice milk and conventional warm yogurt. The study results revealed that walnut purple rice yogurt exhibited greater viscosity than walnut purple rice milk and conventional dairy-based yogurt. Additionally, the former displayed enhanced stability and recovery ability. Notably, distinguishable differences were observed between the three types of yogurts in terms of the presence of unknown volatiles and the umami signal as indicated by electronic nose/tongue and GC-IMS analyses. The umami flavour of walnut purple rice yogurt surpasses that of traditional dairy-based yogurt, whilst its salty taste is lower than that of walnut purple rice milk. Despite possessing a weaker aroma than dairy-based yogurt, it is more potent than walnut purple rice milk. Additionally, its relative abundance of olefins, ketones, and alcohols enhances its unique flavour profile, surpassing both other options. Based on sensory analysis, it can be deduced that walnut purple rice yogurt has the highest overall acceptance rate.

Aroma is one of the most fascinating and least-known mysteries of Baijiu research. The volatile compounds (VOCs) of potato wine were evaluated by sensory omics techniques in order to comprehend their overall flavor characteristics and investigate the effects of ultrasonic treatment and gamma irradiation therapy on the aroma of the wine. The findings revealed that a total of 14 flavor compounds were identified by GC-MS. Isoamyl alcohol, ethyl octanoate, and 1,1-diethoxyethane were the key aroma components, according to GC-O analysis. A total of 50 volatile substances were identified by GC-IMS. After being subjected to irradiation and ultrasonic treatment, the alcohol level of the potato wine reduced while the esters content increased. By calculating the relative odor activity value, a total of 29 aroma components were classified as key aroma compounds (ROAV > 1). According to the results of the sensory evaluation—fruity, Fen-flavor, and sweet—and the acceptability of the irradiated and ultrasonicated potato wine were improved. Therefore, the use of ultrasonic and irradiation therapy in potato wine, as well as the overall aroma building of potato wine, can be supported theoretically by this study.