Optimization of fermentation technology of a mulberry-grape compound fruit wine by response surface methodology and its flavor characteristic

Using mulberry (Black Pearl) and grape (Cabernet Sauvignon) as the raw materials to develop mulberry-grape compound fruit wine, the fermentation technology was optimized by single factor tests and response surface tests, and the volatile flavor components characteristics were analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the optimal mass ratio of mulberry to grape for mixed fermentation was 1:4, the optimum fermentation technology was as follows: yeast inoculum 2.0%, fermentation temperature 24 ℃, and time 9 d. Under the optimum condition, the alcohol content of the fruit wine was 13.6%vol, and the sensory score was 90. A total of 50 volatile flavor components were identified by GC-MS, including 20 alcohols, 9 esters, 10 acids, 3 aldehydes, 3 phenols, 1 ketone, 2 ethers, and 2 olefins. Mulberry-grape compound fruit wine was dark purple in color, deep and stable, and the fruit aroma was in harmony with wine aroma, which is a fruit wine with unique flavor and nutritional function of both mulberry and grape.