Study On Fermentation Promoter Of MLF In Wine

Malolactic fermentation (MLF) is a indispensable processing technology for modern wine making, especially for red wine of high quality.In developed wine making countries, most of the wineries use commercial fermentation promoters which are based on nutrition requirements of LAB to inoculate MLF.These fermentation promoters include amino acids, vitamins and other nutrients for LAB to reproduce, so can make the MLF faster and successful. But research on this is scarcely at home. Startup of MLF depend on the species of LAB and the conditions of the wine(.content of ethanol, SO2 pH,etc.).In practice, MLF is often sluggish and appears fall of inoculation.It is indispensable to prepare a Fermentation Promoter based on nutrition requirements of LAB,so it can make the MLF faster and more successful.This paper studied on the best proportion of the nutrition requirements of choice Oenococcus oeni SD-2a.in the process of fermentation,vacuum freeze-drying craft of tomato juice, the composition and application of Fermentation Promoter. The purpose is to provide an experimental basis for preparation of Fermentation Promoter. The results indicated:1.The best proportion of the nutrition requirements of Oenococcus oeni SD-2a is 30% tomato juice,isoleucine,methionine,valine,leucine,aspartic acid which are 0.03g/L apiece,tryptophan,Hcl-cysteine,arginine and proline which are 0.01g/L apiece ,0.2g/LMgSO4,0.05g/LMnSO4.2.Discussing the influence of shelf temperature, material thickness and other factors on freeze-drying time and quality of tomato juice: freeze-drying time is shortened 2 to 3 hours while shelf temperature raises 10℃; thickness raises 2.0mm while freeze-drying time delays 2 hours. Freeze-drying craft parameters of tomato juice: advance freezing temperature is -35℃,shelf temperature is 50℃,material thickness is 5.0mm. 3.When MLF conducted by using Oenococcus oeni SD-2a powder,adding fermentation promoter or not have marked difference. Malic acid division rate is 42.81% when adding no fermentation promoter , Malic acid division rate are 72.04% and 69.83% when adding fermentation promoter including tomato juice and tomato juice powder.So adding fermentation promoter can decrease the content of malic acid remarkably.