Selection Of Kiwi Fruit Wine Yeast Producing Little Higher Alcohols

Aiming at the problem raised by Jiangxi kiwi fruit wine Co. Ltd., which is that there are too high level of higher alcohols in fruit wines, we attempt to resolve it by yeast selection.First, a yeast, named SYS2000, was selected from kiwi fruit pericarps and soil obtained from Jiangxi kiwi fruit plantation. It was proved to produce little higher alcohols 40% lower than the yeast the company originally used and has good descendiblity stability by fermentation experiment. The yeast SYS2000 was identified as Saccharomyces cerevisiae.Kinetics of cell growth and higher alcohols producing of yeast SYS2000 was studied, and the result indicated that the production of higher alcohols was closely correlative with, but at the same time 14-18 hours later than, cell growth.The higher alcohol concentrations as the criterion, orthogonal experiments were carried out at three different factors and levels, and the result indicated that the best fermentation condition is fermentation temperature 16℃, inoculation concentration 1×107cell/ml and natural juice pH. Fermentation experiment turned out higher alcohols produced fermenting at 16℃ is 42% lower than that at 25℃. Under that best fermentation condition, Influence of kiwi fruit species on higher alcohols was studied, and the result told us the higher alcohols produced fermenting with different kiwi fruit species is 30% different. The higher alcohols produced fermenting without kiwi fruit pericarp have no obvious differences with that produced fermenting with kiwi fruit pericarp; Adding sugar twice during fermentation could make higher alcohols produced lower than adding sugar once; If the SO2 concentration is more than 120mg/l, fermentation will lag obviously, and higher alcohols produced are obviously high, the reason that led to which may be SO2' restraining growth of yeast cells.Experiment on pilot-plant scale was carried out in Jiangxi kiwi fruit wine Co. Ltd., and the result proved the low-higher-alcohol-production character of yeast SYS2000 again. At same fermentation condition, higher alcohols produced by SYS2000 is 42.5% lower than that produced by comparison yeast. By flavor analyses and organic assess, the kiwi fruit wine fermented with SYS2000 was thought to have a great improvement than before.