Search

With the increasing awareness of health, more people have shown a preference for low-alcohol beverages. Seeking various methods to improve the quality of kiwi wine is now a major research interest in the wine industry. In this study, kiwi wine was fermented by Saccharomyces cerevisiae and different non-Saccharomyces strains (Torulaspora delbrueckii, Kluyveromyces thermotolerans, Pichia fermentans) in three methods (pure fermentation, simultaneous, and sequential co-fermentation). The physicochemical characteristics, color parameters, phenolic profiles, total phenolic content (TPC), antioxidant activities, organic acids, and taste sense of the different wines were evaluated to determine the effects of different yeasts and fermentation methods on the quality of the kiwi wine. Results indicated that co-fermentation reduced the contents of alcohol while enhancing the lightness of the kiwi wine. The TPC of sequential co-fermentation with K. thermotolerans/S. cerevisiae was significantly higher than that of their simultaneous co-fermentation. Compared to K. thermotolerans/S. cerevisiae, the antioxidant activities were increased by co-fermentation of T. delbrueckii/S. cerevisiae and P. fermentans/S. cerevisiae. Principal component analysis showed that kiwi wines fermented by different yeasts and inoculation methods could be separated and grouped. Correlation analysis presented positive correlations of phenolic composition, antioxidant activities, and color intensity. This study provided theoretical guidance for co-fermentation of non-Saccharomyces/S. cerevisiae and accelerated the industrialization process of kiwi wine. [ABSTRACT FROM AUTHOR]

To enhance the storage time of cucumbers, this research investigated the impact of chitosan (CS) and hyperbranched poly-L-lysine (HBPL) on the quality and nutritional attributes of cucumbers when stored at a temperature of 25 °C. The results demonstrated that sensory evaluation scores for cucumbers treated with a CS–HBPL combination were significantly higher than the control (CK), CS, and HBPL groups. On the 18th day of storage, cucumbers in the CK group exhibited significant decay and softening; however, there was a decrease in hardness observed in the CS–HBPL group and no decay or noticeable sour taste was detected. Furthermore, compared to the CK group, treatment with CS–HBPL effectively delayed cucumber decay and weight loss rate while significantly inhibiting decreases in cucumber hardness and growth of surface microorganisms. Additionally, it substantially reduced losses of soluble protein content as well as vitamin C (Vc), reducing sugars, and total phenolic compounds within cucumbers, which were 4.7 mg/g, 4.7 mg/g, 0.94 mg/g, and 0.52 mg/kg, respectively. Moreover, compared to the CK group, combined treatment with CS–HBPL significantly inhibited malondialdehyde (MDA) accumulation and reducing relative electrolyte permeability within cucumbers, which were 1.45 μmol·g−1FW and 29.82%. Furthermore, it notably enhanced activities of superoxide dismutase (SOD) and catalase (CAT), while exerting a significant inhibitory effect on polyphenol oxidase (PPO). In summary, the combined CS–HBPL treatment successfully prolonged cucumber shelf life at room temperature, enabling new possibilities for extending cucumber shelf life. [ABSTRACT FROM AUTHOR]

To extend the shelf life of oyster mushroom (Pleurotus ostreatus), the effects of chitosan (CS) and hyperbranched poly-L-lysine (HBPL) combined treatment on quality characteristics, nutritional quality, storage characteristics, and enzyme activity of oyster mushroom during postharvest storage at 4 °C were investigated. The results showed that CS-HBPL combined treatment could significantly reduce rot degree and weight loss and significantly inhibit the browning of oyster mushroom. At the same time, the loss of reducing sugar, vitamin C, soluble protein, and total phenolic was significantly reduced. Compared with the control, CS-HBPL combined treatment could also significantly inhibit an increase in malondialdehyde (MDA) and significantly decrease the relative electrolyte leakage of oyster mushroom. In addition, the activities of catalase (CAT), superoxide dismutase (SOD), phenylalnine ammonialyase (PAL), and peroxidase (POD) were significantly improved, and the activity of polyphenol oxidase (PPO) was significantly inhibited in oyster mushroom. In conclusion, CS-HBPL combined treatment had a good protective effect on the membrane permeability damage of oyster mushroom and could effectively delay the oxidation of phenolic substances and browning of oyster mushroom. Therefore, CS-HBPL combined treatment can be used as a potential strategy to extend the storage time of oyster mushroom. [ABSTRACT FROM AUTHOR]

This paper took the Cabernet Gernischt dry red wine as the research object, and analyzed the changes in the content of total phenols, main phenolic compounds, total acids, and main organic acid compounds in the wine under different microwave treatment conditions (power, temperature, time and mode) to explore the specific influence mechanism of microwave on wine flavor changes. The results show that different microwave treatment conditions have different effects on phenols, organic acids and their compounds. The content of caffeic acid, gallic acid and Mv-3-glu are increased, and the content of total phenols, catechins, total acids, acetic acid, citric acid and malic acid are decreased. The effect on the content of Cy-3-glu, syringic acid, tartaric acid, lactic acid and oxalic acid is little. The content of phenols, organic acids and their compounds in wine after 100 W, 6 min, 40 °C and intermittent microwave treatment are basically the same as the change trend in the natural aging process. [ABSTRACT FROM AUTHOR]

In Older to clarify the affinity interaction of reactive blue 4 (RB-4), the molecular mechanism of the interaction between RB-4 and bovine serum albumin (BSA) was studied by ultraviolet absorption spectrum, fluorescence spectrum and molecular docking method. The results show that the hydrophobic groups in BSA are exposed by the interaction between RB-4 and BSA. RB-4 is reacted with BSA through static quenching mechanism, and the number of binding sites is about 2. The thermodynamic parameters of binding process are calculated as Δ C < 0 as well as ΔH and Δ 5 > 0, which suggest that the binding process is a spontaneous exothermic process and the main force is hydrophobic interaction. The tertiary structure of BSA is disrupted after the binding between RB-4 and BSA. The hydrophobicity of the microenvironment around the tyrosine residues and tryptophan residues is enhanced. The key interaction sites of amino acid is Phe-567, Ala-568, Ala-510, Val-575, Pro-572, Phe-508 and Phe-506, and there are certain electrostatic interaction and hydrogen bonding interaction at the same time. [ABSTRACT FROM AUTHOR]

Natamycin is a polyene macrolide antibiotics with strong and broad spectrum antifungal activity. It not only effectively inhibits the growth and reproduction of fungi, but also prevents the formation of some mycotoxins. Consequently, it has been approved for use as an antifungal food preservative in most countries, and is also widely used in agriculture and healthcare. Streptomyces natalensis and Streptomyces chatanoogensis are the main producers of natamycin. This review summarizes the biosynthesis and regulatory mechanism of natamycin, as well as the strategies for improving natamycin production. Moreover, the future perspectives on natamycin research are discussed.