Study On Fine Strains Breeding And Quality Of Fermented Fresh Rice Flour

Rice flour is a rice as raw material,after soaking,fermentation,grinding,extrusion molding of a rice products.The traditional rice flour production had the fermentation method and the non fermentation method.Non fermentation process for the production of more family workshops,backward technology,poor quality of health,has been less used.The natural fermentation influenced by the environment,easy to breed bacteria,perishable products taste and quality is not stable.In this paper,the dominant strains in rice fermentation broth were screened,and enhanced fermentation of dominant strains.Study on its fermentation characteristics and its effect on the quality of fortified rice flour.The main research contents and results are as follows:(1)The lactic acid bacteria and yeast were isolated and purified from the fermentation broth of rice.The bacterial strain were identified as Lactococcus lactis,Streptococcus salivarius,Lactobacillus plantarum and Saccharomyces cerevisiae based on its morphologic properties,physiological and biochemical and sequences.(2)The dominant strains were fermented by single and mixed bacteria,and determined their protease activity and amylase activity.The results showed that all the strains had amylase and protease activity,amylase and protease activities of mixed fermentation was stronger than that of single strains.The Lactococcus lactis + Streptococcus salivarius +Lactobacillus plantarum mixed strains of amylase and protease activity was the strongest,amylase activity was 10.58 U/g,and protease activity was 2.82 U/g.The amylase activity and protease activity of yeast were the lowest,4.73 U/g,0.44 U/g.(3)Lactic acid content were determined in natural fermentation liquid,single and mixed rice fermentation liquid.The results showed that the content of lactic acid in natural fermentation broth was the lowest,which was 14.7 mg/100mL.The content of lactic acid in the fermentation broth of the mixed bacteria was higher than that in the single fermentation broth,inoculating Lactococcus lactis + Streptococcus salivarius + Lactobacillus plantarum mixed bacteria lactic acid content in solution is the highest,59.88 mg/100mL.(4)By Lactococcus lactis,Streptococcus salivarius,Lactobacillus plantarum and Saccharomyces cerevisiae intensified fermentation rice noodles,the results showed that the inoculation of Lactococcus lactis + Streptococcus salivarius + Lactobacillus plantarum three microbial fermentation of the rice noodles of amylose content,starch increased,amylose content was 41.78%and total starch content was 75.34%.Protein and fat content is low,respectively,0.16%,4.15%.Texture and the sensory evaluation results showed that the rice noodles elasticity,chewiness,resilience and taste is superior to the other intensive fermentation.