Development Of Chestnut Glutinous Rice Sake

Chestnut is a woody grain fruit tree native to China,the planting area has developed rapidly and the total output has been continuously improved recent years.However,there are some problems in chestnut industry,such as low level of deep processing technology,single product type,less biological processing products and so on.Therefore,we intend to develop a chestnut glutinous rice sake with chestnut as the raw material for brewing.The specific research results are as follows:1.Study on the selection of koji strains and the process of koji making.Firstly,the activity of ?-amylase,glycosylase and acid protease was compared,it was confirmed that Aspergillus oryzae 2011 was more suitable as a saccharified koji of chestnut sake.Then the effects of five single factors including steamed rice water consumption,inoculation amount,culture time,culture temperature and turning mode on the activity of the finished enzyme were studied.Finally,orthogonal test was used to determine the best technology for making koji.Through experiment,the optimal koji process parameters were:the inoculation amount was 4 mL/100 g,the culture time was 72 h,the culture temperature was 34?,and the liquefaction force of the rice koji was 591.65 U/g under this condition,saccharfication power was 3079.53 U/g.2.Research on fermentation technology and sensory analysis of chestnut and glutinous rice sake.Firstly,the contents of protein and fat in chestnut and glutinous rice were measured.It is determined that chestnut can be used as a raw material for brewing,and the amount of chestnut added should not exceed 30%.At this time,the protein and fat content in the mixture were 1.50%~2.29% and 0.27%~0.64%,respectively.Secondly,through the analysis of the physicochemical indexes and sensory score,the effects of six factors on the quality of chestnut glutinous rice sake were studied,including chestnut addition,rice koji addition,yeast addition,ratio of material to water,initial pH of wine and main fermentation time.Then optimization experiment of chestnut glutinous rice wine brewing process was carried out on the basis of single factor test results.The best brewing conditions for chestnut glutinousrice sake were: the addition of chestnut was 19.6%,the addition of rice koji was 26%,the amount of yeast added was 0.25%,under this condition,the alcohol content of chestnut glutinous rice sake was 12.3%vol,the total sugar was 8.64 g/L,the total acid was 4.77 g/L,the pH was 4.03,the soluble solids were 11.7%.Finally,an intuitive sensory tasting score was obtained for the chestnut glutinous rice sake fermented under optimal parameters,SPME and GC-MS were used to detect the aroma components in chestnut glutinous rice sake.The wine was light yellow and transparent,and the taste was sweet.A total of 84 compounds were detected in the chestnut glutinous rice sake.The main aroma components were isoamyl alcohol,phenylethyl alcohol,diethyl succinate,ethyl acetate,ethyl hexanoate and ethyl octanoate.3.Biological activity of chestnut glutinous rice sake.At first,he total phenolic content of chestnut glutinous rice wine was 187.1 ?g/mL,and the flavonoid content was 106.5 ?g/mL,which was significantly higher than that of glutinous rice sake(p<0.05).And the FRAP of chestnut glutinous rice wine was 1.62 mmol/L,which showed better oxidation resistance to linoleic acid auto-oxidation inhibition,DPPH,ABTS,OH clear removal ability,and was significantly higher than glutinous rice sake(p<0.05),while its metal chelate ability was poor,there was no significant difference with glutinous rice sake.Finally,the chestnut glutinous rice sake was determined to be rich in 17 amino acids,including 8 kinds of essential amino acids.The contents of Gly and Cys in chestnut glutinous rice wine were significantly higher than those in glutinous rice glutinous wine(p<0.05),and the other 15 amino acids were significantly higher than glutinous rice glutinous rice(p<0.01).