| Ginger(Zingiber officinale Roscoe),as a kind of common spices,have been extensively cultivated around the world,especially in China,which can be used to treat some symptoms,such as headache,cold,osteoarthritis,muscle pain and so on in medicine except for spice.In addition to starch,protein,inorganic and other common nutrients,it also includes some substances with special biological activities,such as shogaol,gingerol,cardanol and so on,which can be used as a potential health factor for the production of health products.Because of high antioxidant activity.However,the content of these high biological components in ginger is less than 0.1%,thus limiting the development of high value-added health products.At present,the promotion of ginger's activity mainly depends on the strong physical and chemical treatment,with low efficiency,high cost and serious waste of resources.There are few researches on the transformation of ginger by microbial fermentation.In addition,with the increasing demand for health products,ginger wine has become popular as a new type of health wine in recent years.The common ginger wine production technology in the market is mainly after the completion of base wine brewing,adding fresh ginger juice for blending,or put ginger slices into the wine to brew.The finished ginger wine with light yellow color,heavier ginger spicy taste,and pale flavour,which limited the sale of ginger wine.In this study,three representative microbial varieties of Yeast,Rhizopus and Aspergillus in traditional brewing industry were selected to study their antioxidant activity.Three kinds of microorganisms were inoculated and cultured in PDA medium,and through bacteriostatic test,fresh ginger juice with appropriate ratio of material to liquid was selected for fermentation.Through indexes such as microbial biomass,p H change of culture medium and antioxidant activity,the influence of different microorganisms on antioxidant performance of fresh ginger juice was analyzed.On the basis of single factor experiment,ginger addition,inoculation scale,culture temperature and culture time was selected as the independent variable,the total antioxidant capacity as response value.The BBD experiment was chose to determine the optimal culture conditions among S.cerevisiae J12-7,R.oryaze MG1 and A.oryaze,and the experimental results were analyzed and summarized respectively.The liquid bacteria agent was prepared with three types of microorganisms,and the special ginger yelow wine was developed according to the traditional fermentation process of yellow wine.The optimal fermentation parameters of yellow rice wine were determined by PB experiment,single factor design and BBD experiment respectively.In order to facilitate the storage,transportation and utilization of the bacteria agent in production,the special ginger yellow wine direct cast compound drying bacteria agent was developed based on the the fermentation of special ginger yellow wine.The optimum inoculation proportion of each microorganism in the liquid bacteria agent was determined by the mixture test,and then the optimum drying parameters were determined by the single factor design and BBD experiment.The main results are as follows:(1)The analysis about the effect of Yeast fermentation on the antioxidant activity of ginger can provide a theoretical basis for the development of ginger health products with high added value.S.cerevisiae J12-7 showed good fermentation potential and total antioxidant activity.Through single-factor experiment and response surface analysis,it was found that the optimal fermentation condition was to add 400 ?L of fresh ginger juice with a feed-to-liquid ratio of1:8 in 20 m L PDA medium,and inoculated 1.51% S.cerevisiae J12-7 seed solution,then cultured for 96 h at 28.69 ?,the antioxidant activity of the cultured fresh ginger juice after fermentation was about twice higher than that of the control group.(2)The effect of Rhizopus on antioxidant activity of ginger was analyzed,which can provide reference for the efficient utilization of ginger resources.In the study of the effect of Rhizopus on the antioxidant activity of fresh ginger juice,it was found that R.oryaze MG1 had the highest conversion degree to the active substances of fresh ginger juice.Through single factor experiment and response surface analysis,it has found that the best fermentation conditions was to add 180 ?L of fresh ginger juice with a feed-to-liquid ratio of 1:8 in 20 m L PDA medium,and inoculated 1.91% R.oryaze MG1 spore suspension,then cultured for 5 d at26.49 ?,the antioxidant activity of the cultured fresh ginger juice after fermentation was about1.64 times higher than that of the control group.(3)The influence of Aspergillus on the antioxidant activity of fresh ginger juice was studied.By single factor experiment and response surface analysis,it has concluded that the best fermentation condition was to add 228 ?L of fresh ginger juice with a feed-to-liquid ratio of 1:8 in 20 m L PDA medium,and inoculated 1.32% A.oryaze spore suspension,then cultured for 5 d at 26.18 ?,the antioxidant activity of the cultured fresh ginger juice after fermentation was about 1.34 times higher than that of the control group.(4)In the production process of special ginger yellow wine,the optimal levels that meet the criteria in the raw materials,sort of quyi,fruit juice and sugar content were screened out for the production of special ginger yellow wine through the main indexes and sensory evaluation of yellow wine were analyzed.Plackett-burman Design was used to determine the main significant factors including ginger juice addition,inculation scale,pre-fermentation temperature and fermentation time for subsequent experiments.The single factor experiment and Box-Behnken Design were used to determine the optimal levels of each factor,that is,ginger juice addition(24.10 m L),mixed inoculation(1.00%),pre-fermentation temperature(24.03 ?)and fermentation time(26 d).After the optimization,the special ginger yellow rice wine has deep color,soft taste,and low alcohol content,which was more suitable for drinking.(5)In the process of developing the direct cast compound drying bacteria agent of special ginger yellow wine,the physicochemical indexes and sensory evaluation were evaluated by mixture experiment,and the optimum ratio of four main microorganisms in the bacteria agent was screened,and he final ratio was: S.cerevisiae J12-7:R.oryaze MG1:A.oryaze:A.niger40120 = 0.3560:0.3000:0.1940:0.1500.Through single-factor experiment and Box-Behnken Design,the final experimental drying conditions were determined as mixed inoculation(630 ?L),drying temperature(52.1 ?)and drying time(11 h).The special ginger yellow wine produced under this condition has bright color,strong aroma and sweet taste,providing reference for the ginger deep processing industry and the production of mechanized rice wine. |
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