Research On Key Technology In Fermentation Of Hawthorn Wine

The processing technology of hawthorn wine using hawthorn as the main raw material was studied in this paper.First of all,in the test of the selection of optimal yeast strains,4 kinds of active dry yeast were compared by some indices such as the growth curve,the tolerance of alcohol,reducing sugar content,alcohol content,flavonoid content,anthocyanin content and titratable acid.Secondly,researches of fermentation conditions including fermentation temperature,yeast inoculum and sulfur dioxide content were conducted by comparing reducing sugar content,alcohol content.And then,the method and the performance of tow immobilized carriers made by sugarcane and gluten was investigated by the amount of fixed yeast,repeating fermentation experiments,electron microscope observations.Finally,the volatile composition of the fruit of hawthorn and the fruit wine of hawthorn were extracted by headspace solid phase micro-extraction(HS-SPME)and analyzed by gas chromatography/mass spectrometry(GC-MS).The contents and results are as follows:Four strains of active dry yeast were compared,including the Angel grape wine dry yeast RV171,the Angel high-active dry yeast RV171,French Laffort Actiflore F33,French Laffort zymaflore FX10.Results showed that after yeast RV171 inoculation,10 hours was logarithmic phase and stagnate phase was from 25 hours.Yeast RV171 showed good ability of cells to grow and the best ability of tolerance to alcohol in the range 15%vol.Under the same fermentation conditions,the fermentation period of yeast RV171 was the shortest time(12 days),the alcohol content was also the best one(7.6%vol).So the Angel brand high-active dry yeast RV171 was the optimal yeast strains for fermentation of hawthorn wine.After single factor test and orthogonal test,the optimal processing conditions were as follows:fermentation temperature was 25?,yeast inoculum was 2.5 g/L,sulfur dioxide content was 60 mg/L.The alcohol content of Hawthorn wine according to the optimal fermentation conditions was 7.8%vol.The effect on pretreatment to tow kinds of immobilized carriers showed that sugarcane was adapted to immobilized without pretreatment and the gluten treared after fermentation were used as two higher-performance immobilized carriers than the one without fermentation.It was observed that yeast can be fixed in sugarcane carrier and gluten carrier by electron microscope.The number of repeating fermentation experiments indicated that the immobilized carriers made by sugarcane can reuse in 4 times and the immobilized carriers made by gluten can reuse in 3 times.The volatile components of fruit of hawthorn were extracted by HS-SPME and analyzed by GC-MS.20 kinds of volatile components were identified from hawthorn,including 10 kinds of esters,5 kinds of hydrocarbon,3 kinds of alcohols,1 kind of ether,1 kind of heterocyclic compound.High contents of volatile components(relative area>1%)were as follows:3-hexen-1-ol acetate,D-limonene,2-furanmethanol acetate,acetic acid,hexyl ester,hexanoic acid methyl ester,1-methoxy-hexane,hexyl butanoate,octanoic acid methyl ester,a-terpineol,2-hexen-1-ol acetate,(3-methyl-oxiran-2-yl)-methanol.Most of the aroma components were composed of esters and alcohols.11 kinds of volatile components were separated from hawthorn wine through HS-SPME and identified through GC-MS,which including 6 kinds of alcohols,3 kinds of esters,1 kind of ether and 1 kind of acid.Alcohol compounds included 3-methyl-1-butanol,1-pentanol,2-methyl-1-propanol,butanl,2,3-butanediol and phenylethyl alcohol.Esters compounds included decanoic acid ethyl ester,octanoic acid ethyl ester and dodecanoic acid ethyl ester.Dimethyl ether and acetic acid were also analyzed.