Fermentation process optimization and quality analysis of red grape Musalais in Xinjiang

Based on the traditional techniques of Musalais, red grape Musalais was brewed using red grape in Xinjiang as the raw material. The fermentation process conditions were optimized by single factor tests and response surface tests, and the quality indexes were analyzed. The results showed that the optimal fermentation process conditions were as follows: mass ratio of skin residue and water 1.0∶1.3, initial sugar content 25 °Bx, and initial pH 3.7. Under these optimal conditions, the red grape Musalais was bright, with red tone, round taste, and unique style of Musalese. The sensory score was 90 points, the alcohol content was 11.36%vol, the contents of total phenol, total acid, volatile acid, and residual sugar were 449 mg/L, 7.2 g/L, 0.6 g/L and 17.15 g/L. The red grape Musalais had certain flavor and nutritional advantages, which could provide references and technical supports for the deep processing of red grape and the development of new products of Musalais.