Screening and identification of superior wine yeast strains and their effects on the quality of red raspberry fruit wine
摘要
To screen superior yeast strains suitable for red raspberry fruit wine fermentation, using wild red raspberry fruits, orchard soil, and natural fermentation broth as isolation sources, the strains were preliminary screened using 2,3,5-triphenyltetrazolium chloride (TTC) colorimetric method, secondary screened by tolerance and fermentation performance tests, and identified by morphological observation and molecular biological techniques. The red raspberry fruit wine was simulated to ferment, and the physicochemical indicators, sensory quality and volatile flavor substances were analyzed. The results showed that a total of 24 yeast strains were preliminarily screened using TTC colorimetric method, from which 3 strains (numbered as YSM-1, YSM-8 and YSM-10) with excellent ethanol and sulfur dioxide tolerance were screened. These strains were identified as Saccharomyces cerevisiae. Among them, the quality of red raspberry fruit wine brewed by strain YSM-10 was the highest, and the alcohol content, total sugar, total acid and sensory score were 14.7%vol, 9.24 g/L, 13.22 g/L, and 92.8, respectively. A total of 59 volatile flavor compounds were detected, among which alcohols, esters and ketones had relatively high contents (61.91%, 29.92% and 5.16%). Compared with fruit wine brewed by yeast SY, the relative contents of volatile flavor substances such as isoamyl alcohol, phenethyl alcohol, ethyl benzoate, ethyl octanoate, α-ionone and β-ionone increased 11.18%, 14.10%, 2.97%, 4.49%, 11.94% and 13.29%, respectively, which could endow red raspberry fruit wine with typical red raspberry fruit aroma and floral aroma. Therefore, strain YSM-10 had certain potential for brewing fruit wine with the flavor characteristics of red raspberry.