Effects of multiple cycles of sorghum starch gelatinization and fermentation on production of Chinese strong flavor Baijiu

The property changes of sorghum starch during multiple cycles of gelatinization and fermentation were studied. This study simulated the gelatinization and fermentation process of raw starch in strong-flavor Baijiu production (Sorghum as raw material, the distillers' grains as a control). The results showed that the starch content of the same batch of sorghum after five cycles of gelatinization and fermentation was 9.98% (Cannot continue to be used for fermentation), and about 60% of the starch was consumed in the first three cycles of gelatinization and fermentation. The gel properties of sorghum starch gradually decreased during fermentation but slightly increased after gelatinization. After five cycles of gelatinization and fermentation, the sorghum starch has a uniform size and a thin and small fragment structure. At the same time, sorghum starch does not form new groups. The recrystallization of starch caused by multiple cycles of gelatinization and fermentation increased the onset gelatinization temperature (from 61.6 to 114.4 °C), peak gelatinization temperature (from 78.5 to 139.5 °C), and gelatinization enthalpy (from 7.980 to 17.121 J/g) of sorghum starch. The crystalline structure of sorghum starch changed from the initial type A to type A + V, type A + B + V, and finally to type B. Fig The process of multiple gelatinization and fermentation. • The crystal structure, gel properties and gelatinization properties of raw starch in Baijiu production process were studied. • The effects of five cycles of gelatinization and fermentation on the properties of sorghum starch were studied. • The changes of residual starch content and proportion of amylose in distiller's grains were studied.