Research Of The Selection Of Prominent MLF Bacteria And Deacidification Processes Of Northeast V.amurensis Wines

Wild grape is a black purple globose berry,with blue-white fruit cream,and growing in Northeast Asia.The grape grain is small,has a thick skin,low sugar content,high acidity and concentrated pigment.Vitis amurensis wines is rose red,fruity bouquet and very palatable,with a pleasant finish.And it is high in polysaccharides,amino acids,vitamins,along with proanthocyanidins,flavonoids,resveratrol and other substances with high biological activity.Due to the malic acid content higher and bitter taste,it is difficult to produce high grade dry red wine,which restricts the development and utilization of wild grape wine.The aim was selecting acid-resisting of malic-lactic acid bacteria from dry red wine,looking into the deacidification process of malolactic fermentation,providing sources for grape wine deacidification and improving texture and flavor of grape wine.In this paper,it is selected a wine high-acidity grape wine legs as inoculum source.This study was selected high-acidity endurance of lactic acid bacteria from Jiamusi mountain estate wines,conducting a physiological and biochemical identification of screened strains,obtained by ultraviolet ray mutation of deacidification more powerful mutants,and the malolactic fermentation process conditions were optimized in the northeast mountain wine under high acid environment.The results showed:1.we were considered 24 higher-acidity grape wine legs as sources.Inoculated into wild grape wine completed the main fermentation,we had monitored the pH before and after malolactic fermentation,16 sets of wine samples pH increased.Through the accumulation and plate separation method,5 strains of lactic acid bacteria was isolated and purified from 16groups of wine.Using bromocresol purple-reducing acid medium of instruction,it was filter out malolactic fermentation high ability of 3 strains.It was inoculated into wild grape wine,compared with lactic acid bacteria 450 PreAC,testing pH and total acidity value.It is resulted that the strain MLB-11 had better ability of malolactic fermentation.2.The identification of the strain MLB-11 screened out was involved with morphology,gram stain,catalase test,and the physiological and biochemical identification of bacteria.O.oeni-11 in medium plate was forming creamy,surface smooth colonies,diameter less than1mm.Cell shape was spherical or oval,tsunenari to appear,and arranged in chain-like conformation.The germ was a gram-positive,negative hydrogen peroxide and inactivity.Only fermentation of partial carbohydrates,the sugar,glucose,melibiose,it couldn't fermented Sucrose,maltose,cellobiose,lactose.It can be converted malic acid to L-lactic acid and CO₂.It was preliminarily judged strains MLB-11 isolated as Oenococcus.3.Enhance malolactic fermentation ability screening by mutagenesis of ultraviolet irradiation.After pre-experiment,it was to determine the basic conditions of O.oeni-11 UV mutagenesis.Logarithmic strain was excellent mutagenic material.Keep a distance from the UV light source to mutated strain up to 25cm.UV lamp power was 15W,UV irradiation time of100s.Through mutagenesis,screening and screening,O.oeni-11 screened out was inoculated into wild grape wine to consider reducing acid capacity.The strain O.oeni-11 obtained made grape wine pH value increase 0.20,total acidity reduce 2.26g/L.Ability to reduce the acid is better than O.oeni-11.4.The optimum process conditions was screened with Oenococcus fermented.By single factor experiments and orthogonal experiment,the malolactic fermentation conditions were optimized,which was involved with inoculation,initial pH,temperature,fermentation time.It is resulted that initial pH had more great impact on malolactic fermentation,followed by temperature,inoculation,fermentation time.The optimum conditions was inoculation 6%,temperature 20?,initial pH 3.00,fermentation time 18d,in favor of Oenococcus malolactic fermentation and improvement of grape wine flavor.