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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]

Acid-resistant bacteria are more and more widely used in industrial production due to their unique acid-resistant properties. In order to survive in various acidic environments, acid-resistant bacteria have developed diverse protective mechanisms such as sensing acid stress and signal transduction, maintaining intracellular pH homeostasis by controlling the flow of H+, protecting and repairing biological macromolecules, metabolic modification, and cross-protection. Acid-resistant bacteria have broad biotechnological application prospects in the food field. The production of fermented foods with high acidity and acidophilic enzymes are the main applications of this kind of bacteria in the food industry. Their acid resistance modules can also be used to construct acid-resistant recombinant engineering strains for special purposes. However, they can also cause negative effects on foods, such as spoilage and toxicity. Herein, the aim of this paper is to summarize the research progress of molecular mechanisms against acid stress of acid-resistant bacteria. Moreover, their effects on the food industry were also discussed. It is useful to lay a foundation for broadening our understanding of the physiological metabolism of acid-resistant bacteria and better serving the food industry. [ABSTRACT FROM AUTHOR]