Effect of Raw Material Pretreatment on Microbial Community Succession during the Fermentation of Persimmon Wine

In this study, persimmon wine was brewed with fresh persimmon pulp (S), frozen persimmon pulp (D), persimmon peel (P), and persimmon pulp treated with tannins (M) under the same conditions. Tannin content and the microbial community structure and diversity during fermentation were analyzed separately in order to analyze dynamic changes to the tannin content and microbial community during the fermentation of persimmon wine following pretreatment with different raw materials and to analyze the differences and correlations between the various raw materials in order to provide a theoretical basis for the later regulation of tannin content in persimmon wine. The results showed that, in all four pretreatments, the tannin content showed a trend of increasing and then gradually decreasing during fermentation, but the tannin content in persimmon wine made from persimmon pulp (M) treated with tannase was always at the lowest tannin content of all the pre-treatments. At the level of the bacterial community structure, the dominant phylum was cyanobacteria on the first day of fermentation, while the dominant phyla from the third day to the ninth day were Firmicutes and Proteobacteria. At the genus level, the dominant phyla varied, with the most frequent phyla being Pediococcus (S), Leuconostoc (D), Acinetobacter (P), Gluconobacter and Pediococcus (M), respectively. At the level of the fungal community, the Cysticercus phylum was dominant. At the genus level, the dominant genera was Saccharomycopsis for all treatments. Persimmon wine with different pre-treatments had a stronger similarity in terms of their fungi during fermentation than in terms of their bacteria. In addition, fresh persimmon pulp (S), frozen persimmon pulp (D), persimmon peel (P), and persimmon pulp fermented by tannase (M) showed significant correlations between tannin content and microbial genera in the fermentation of species 10, 5, 3, and 7, respectively, with different microbial genera. Preliminarily, the raw material pretreatment would affect the tannin content and microbial correlation during the fermentation of persimmon wine.