As a protein extracted from soybeans, soy protein isolate (SPI) may undergo the Maillard reaction (MR) with co-existing saccharides during the processing of soy-containing foods, potentially altering its structural and functional properties. This work aimed to investigate the effect of mono- and polysaccharides on the structure and functional properties of SPI during MR. The study found that compared to oat β-glucan, the reaction rate between SPI and D-galactose was faster, leading to a higher degree of glycosylation in the SPI–galactose conjugate. D-galactose and oat β-glucan showed different influences on the secondary structure of SPI and the microenvironment of its hydrophobic amino acids. These structural variations subsequently impact a variety of the properties of the SPI conjugates. The SPI–galactose conjugate exhibited superior solubility, surface hydrophobicity, and viscosity. Meanwhile, the SPI–galactose conjugate possessed better emulsifying stability, capability to produce foam, and stability of foam than the SPI–β-glucan conjugate. Interestingly, the SPI–β-glucan conjugate, despite its lower viscosity, showed stronger hypoglycemic activity, potentially due to the inherent activity of oat β-glucan. The SPI–galactose conjugate exhibited superior antioxidant properties due to its higher content of hydroxyl groups on its molecules. These results showed that the type of saccharides had significant influences on the SPI during MR.

Three kinds of phenolic acid-grafted soluble soybean polysaccharide (SSPS) with similar grafting ratios were prepared, and their structure was characterized by FT-IR, UV-vis and ¹ H NMR. The impact of phenolic acid on the antioxidant activity of SSPS was evaluated. Then, films were prepared by using phenolic acid-grafted SSPS. The physical, mechanical and biological performances of phenolic acid-grafted SSPS films were further investigated. The results indicated that an ester linkage was formed between the SSPS and phenolic acid. The grafting ratio of para-hydroxybenzoic acid, protocatechuic acid and gallic acid-grafted SSPS was 29.45, 31.76 and 30.74 mg/g, respectively. Phenolic acid endowed SSPS with improved antioxidant properties. Gallic acid (GA)-grafted SSPS possessed the best DPPH radical scavenging ability and reducing power, which may be related to the three phenolic hydroxyl groups in GA. Phenolic acid-grafted SSPS films showed increased moisture content and decreased water solubility compared to SSPS film. The phenolic acid-g-SSPS decreased the mechanical properties but enhanced the water vapor barrier property, and antioxidant and antibacterial properties of SSPS film. Meanwhile, the para-hydroxybenzoic acid-grafted SSPS film showed the lowest water vapor permeability (3.70 × 10⁻⁷ g mm/h cm² Pa), and the GA-grafted SSPS film exhibited the best antioxidant and antibacterial activities.

Starter culture significantly influences the texture and flavor of yogurt, making the selection of appropriate fermentation strains a key focus in yogurt starter research. In this study, protease-producing Lactiplantibacillus plantarum NH-24, identified in prior experiments, was combined with Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophiles for yogurt fermentation. Indicators such as coagulation state, acidity, and water-holding capacity were measured to determine the optimal fermentation temperature and starter ratio. Additionally, the effects of this strain on the yogurt’s texture, sensory properties, and volatile flavor compounds were evaluated. The results indicate that a fermentation temperature of 37 °C and a starter ratio of 4:4:3 were most suitable for yogurt production. Further analysis demonstrated that incorporating Lp. plantarum NH-24 improved the yogurt’s texture and flavor while reducing post-acidification during storage. Thus, protease-producing Lp. plantarum NH-24 holds significant promise as a yogurt starter culture.

L-arginine, a semi-essential amino acid, is well-documented for its role in nitric oxide (NO) synthesis, its anti-inflammatory properties, and its modulation of immune responses. Studies suggest it may improve gut barrier function and reduce inflammation in conditions such as colitis or sepsis. However, its specific efficacy in diabetic enteropathy (a complication of diabetes involving intestinal dysfunction, inflammation, and neuropathy) is less studied. To verify whether L-arginine and silkworm pupae components have a role in the treatment of diabetic enteropathy via the regulation of other cytokines and suppression of CD4+ T lymphocyte proliferation, a special medical-purpose formula containing both of these components was tested. For the first time, we have integrated L-arginine and silkworm pupae protein into enteral nutrition formulations for testing its anti-inflammatory potential. We have found that these formulations can improve the characteristics of diabetic intestinal inflammation through nutrient-modulating effects and nutritional efficacy. In addition, L-arginine (L-arginine, L-arg) enhances the immunomodulatory effects of special medical purpose formulas for diabetes mellitus. We utilized an oxidative stress model of small intestinal epithelial cells induced by high glucose and an inflammation model of the small intestine triggered by lipopolysaccharide in mice. The aim was to further investigate the protective effects of L-arginine and enteral nutritional preparations derived from silkworm pupae protein components on the intestinal tract. This research seeks to establish a theoretical foundation for understanding how L-arginine and these nutritional preparations regulate intestinal inflammation in vivo.

Antrodin C, a bioactive component of Taiwanofungus camphoratus, exhibits good immunophysiological and antitumour activities, including a broad spectrum of anticancer effects. Exogenous additives can bind to metabolites during the submerged culture of T. camphoratus and affect secondary metabolite yields. However, the lack of molecular genetic studies on T. camphoratus has hindered the study of the antrodin C biosynthetic pathway. In this study, we conducted a ribonucleic acid-sequencing-based transcriptional analysis to identify the differentially expressed genes involved in the synthesis of antrodin C by T. camphoratus, using inositol and maleic acid (MAC) as exogenous additives. The addition of inositol significantly upregulated carbohydrate and sugar metabolism pathway genes (E3.2.1.14, UGDH, and IVD). When MAC was used, amino and nucleotide sugar metabolism and starch and sucrose metabolism pathways were significantly inhibited, and the associated genes (E3.2.1.14 and E3.2.1.58) were also significantly downregulated. The biosynthesis pathway genes for ubiquinone and other terpene quinones (COQ2, ARO8, and wrbA), which may play an important role in antrodin C synthesis, were significantly downregulated. This study advances our understanding of how the additives inositol and MAC affect metabolite biosynthesis in T. camphorates. This could be beneficial in proposing potential strategies for improving antrodin C production using a genetic approach.