Study On Characteristic Of Polysaccharide From Hakka Rice Wine With Different Koji

Polysaccharide is an important substance in Hakka rice wine and has high market value in the field of development and application of functional food.However,there is relatively little research on polysaccharide in rice wine at home and abroad.The effect of koji on polysaccharides of rice wine has not been studied.In this experiment,three kinds of Hakka rice wine were brewed by adding different koji?Wine A:red koji+wheat koji+wine drug;Wine B:wheat koji+wine drug;Wine C:red koji?,from which the corresponding crude polysaccharides were extracted.The extraction conditions were optimized,and the dynamic content,antioxidant activity,bacteriostatic activity and stability were studied,thus to learn the properties of polysaccharides from different Hakka rice wine.The results were as followed:1.Studied on extraction process of polysaccharide.By screening the effects of three single factor concentration ratio,ethanol concentration and alcohol precipitation time on the extraction rate of crude polysaccharides,it was determined that the concentration ratio of 1/3,1/4,1/5,ethanol concent ration 85%,90%,95%,and ethanol precipitation time 16h,20h,24h were the best investigation level for the orthogonal experiment.The results showed that the influencing factors were ethanol concentration>concentration ratio>alcohol precipitation time,and the three optimized processes were different,crude polysaccharide A was concentration ratio 1/3,ethanol concentration 85%,ethanol precipitation time 24 h,the maximum extraction rate was 0.702%;Crude polysaccharide B was concentration ratio 1/3,ethanol concentration 90%,ethanol precipitation time 20 h,the maximum extraction rate was0.733%;Crude polysaccharide C was concentration ratio 1/4,ethanol concentration 90%,ethanol precipitation time 24 h,the maximum extraction rate was 0.827%.2.Studied on change of dynamic content and antioxidant activity of polysaccharide.The dynamic change trend of the three polysaccharides were almost the same;The polysaccharide content of Hakka rice wine fermented with red koji was higher than compound koji,the highest was 131.6g/L at the early stage of fermentation;And the final content of polysaccharide A,B,C remained at a relatively high level on the 30th day after fermentation,which were 43.0g/L,41.6g/L,54.7g/L;Wheat koji and wine drug made up for the deficiency of the initial fermentation ability of single red koji,and the addition of red koji also enhanced the saccharification ability of rice wine to some extent.All the determination of potassium ferricyanide method,superoxide anion scavenging ability and reduction ability showed that antioxidant capacity were polysaccharide A>polysaccharide B>polysaccharide C.The polysaccharides from Hakka yellow rice wine brewed with compound koji had strong antioxidant activity.3.Studied on the bacteriostasis of polysaccharide.Three polysaccharide had different inhibitory effects on different bacteria,and crude polysaccharide A,B,C had better inhibitory effects on Staphylococcus aureus,Bacillus sp.and Enterobacter coli,the lowest inhibitory concentration were reached 25.00mg/m L,12.50mg/mL,25.00mg/mL;The three polysaccharides showed weak inhibition to Penicillium,Aspergillus Niger and Trichoderma,among which crude polysaccharide B had better inhibitory effect on them,the minimum inhibitory concentrations were 45.00mg/mL,40.00mg/mL,40.00mg/m L;Compared the bacteriostatic effect of 100.00mg/m L crude polysaccharide with that of 1.00mg/ml amoxicillin,the inhibitory effect of crude polysaccharide A,B,C on bacteria was about 1/3¹/2 of amoxicillin,and had a weak inhibitory effect on mold.4.Studied on stability of polysaccharide.Below 20⁸0?,the polysaccharide A,B,C reached the highest content and most stabled at 60?,which were 65.55g/L,48.64g/L and61.65g/L;Increased with the light time of 0⁶ d,the three were all not stabled,contents were decreased by 12.41%,19.00%,33.22%;When pH was 5⁷,polysaccharide was most favorable for the stable existence,reached the highest content and most stabled at pH 5,which was63.00g/L,58.85g/L,66.75g/L;The effect of H₂O₂ on polysaccharides was higher than NaS₂O₃,three polysaccharide was decreased 20.45%,35.74%,56.17%and 17.76%,23.28%,31.00%;Food additives:sodium benzoate,citric acid,V_C,all had smaller effect on polysaccharides;The effect of different metal ions on the structure of three polysaccharides were not the same.In general,the stable strength was polysaccharide A>polysaccharide B>polysaccharide C,compound rice wine's polysaccharides were more stable than single koji under the influence of external factors.