Development Of Starter And Pre-mixed Powder Used For Fermented Rice Cake

Fermented rice cake is a traditional rice food in china,but present manual production style always leads to unstable quality and low output due to the long fermentation time and bacteria phase changes.In this paper,fermentation cultures for rice cake producing were screened and identified on the basis of traditional technology.Starter and pre-mixed power for rice cake producing were made by enlarging of the culture,and this would provide theoretical data for industrialization and fermentation mechanism exploration of fermented rice cake.The main results are as follows:(1) Gain of strainBrettanomyces custersii and Lactobacillus plantarum were screened from rice slurry for rice cake fermentation.The Brettanomyces's production of gas and alcohol was well, and the Lactobacillus's production of acid was well too(2) Optimized technology for fermented rice cake.The optimum technology for fermented rice cake was that soaking indica rice at 30℃for 21h,fermenting the slurry(25 Baume degrees) at 38℃for 1 h,and then steaming.Fermenting rice slurry with yeasts and lactic bacteria made the fermented rice cake alcoholic flavorful and sweet-sour tasty.(3) Studied on the qaulity of fermented rice cake.Fermented rice cake was a typical viscoelastic gel with network configuration of starches.A revised casson formula could well describe the stress-strain relationship of rice cake,and the fitted models could well illustrate its textural properties.(4) Optimized technology for starterThe ingredient for liquid starter was 9:1(Brettanomyces custersii volume/ Lactobacillus plantarum volum) bacterial suspension cultured at 30℃for 24h.The total bacteria counts of yeasts and lactic bacteria were 10~7cfu/mL.Concentrating the liquid starter,filling and then drying atmospherically at 32℃,solid starter with total 10~8cfu/ml of yeasts and lactic bacteria could be obtained.Both the liquid and solid starters were stable during storage,and they made the qualities of fermented rice very well.(5) Optimized formula of compound power.The ingredient for compound power was adding 2%solid starter,7%sugar,0.1% xanthan gum to the main rice flour.Its characteristics were stable when stored at 25℃and 75%humidity.Sugar,amino acid,protein and fat in compound power provided abundant nutrition for microorganisms,and the metabolites of them greatly contributed to flavor of fermented rice cake. (6) Established products standards.Products standards including sensory standards,microbial standards,storage standards,and physical and chemical standards for liquid starter,solid starter and pre-mixed power were established.