Study On The Technology Of Birch Sap Liquor And Determination Of Its Aroma Components

Birch sap is a transparent liquid with faint yellow,rich in nutritive value,containing a variety of amino acids,minerals,vitamins,glucose and biologically active substances.It has heat-care,detoxification,fatigue prevention,anti-aging and other health effects.China's birch resources are abundant.While birch trees be reasonably mined,can increase the utilization of birch sap and enrich the products of birch sap.Using birch sap as raw material,fermentation was conducted by biological method.Three single factors including fermentation temperature,initial pH value and yeast dosage were selected for experiment,Determination of alcohol accuracy in fermentation process,Taking wine precision as evaluation index,Response surface methodology is used to optimize three single factors,The optimum parameters of fermentation process are obtaine.Distillation process is distilled with a full copper distillation pot,Pay attention to the intercept of wine head,wine tail,and the change of the alcohol quality during the two distillation process,Pretreatment of samples by headspace solid phase microextraction,The aroma components of birch sap liquor were detected by gas chromatograph mass spectrometry(GC-MS).The main physical and chemical indexes of birch sap liquor were detected by national standard method,and the birch sap liquor was analyzed according to the test resultsThe best process of Fermentation of birch sap as follows:fermentation temperature of birch sap 23? initial pH value 5.9,yeast addition amount 0.07%,and birch sap fermentation wine alcoholicity obtained was 6%vol.The distillation process uses a copper distillation pot to conduct the distillation.During the two distillations,intercept the 5%of the distillate as the wine head,and use the 20%of the distillate as the tail of the wine,Determine the alcohol content of 55%vol.Through the determination of the physicochemical and hygienic indicators of birch juice liquor finished product,the physicochemical index of birch juice liquor was alcoholic:55%vol?containing solids 0.1 g/L,total esters 3.48 g/L,total acid content 5.2 g/L The content of methanol in the wine 0.31mg/L,the cyanide content 2.67mg/L,and the lead content 0.25mg/L.All of these were within the limited range and meet the requirements of the wine body.According to the experimental results and the reference national standard,birch juice liquor quality standards were established.Altogether 110 kinds of aroma substances were detected by gas chromatography-mass spectrometry technology.During the four aging periods,the esters,alcohols,aldehydes and ketones all increased,and the acids and acetals showed a decreasing trend overall.There are 21 species that main aroma substances are:ethyl acetate,diethyl succinate,ethyl lactate,n-heptanoic acid,phenethyl alcohol,vanillin,ethyl caprylate,4-hydroxybutyrolactone,4-ethyl-2-methoxy phenol,two benzoic acid two isooctyl ester,decic acid,ethyl laurate and so on.Among them,diethyl succinate,hydroxyethyl acrylate,ethyl laurate,hydroxybutyl acrylate,and diisooctyl phthalate,which are substances not commonly found in other liquors,is the main source of unique aroma substances in birch sap liquor.Compared with the original sap,its aroma substances increased about 50 species,and the species also changed greatly.The increase in esters,alcohols,and phenols,improved the aroma of the birch sap liquor,making the birch sap liquor became a full-fledged liquor with a unique style of birch.Which is clear and transparent,no precipitate,no impurities,fresh and gentle entrance,sweet after taste,and own the unique aroma of plants.