A Preliminary Study On The Beverage Of Sugar-free Red Bean Milk Fermented By Lactic Acid Bacteria

The growth ability of lactic acid bacteria isolated from the traditional fermented food in Inner Mongolia were screened in the sugar-free LB medium, and its capability of acid producing and protein decomposition were measured in the red bean milk. Then the protein decomposition capability of selected strain was tamed gradually, and the optimum process conditions of fermented red bean milk were determined through single factor experiment and orthogonal experiment. The results showed that:Three strains (S2-4, Sc8-1 and NM-6) were screened out with good growth ability from 50 lactic acid bacteria strains, and one of the best strain NM-6 was selected by measuring protein decomposition capability in the 4% of red bean milk, and its total acidity and the free amino nitrogen content at 37℃ for 48h were 0.27% and 1.215mmol/L, respectively. After taming, the total acidity and the free amino nitrogen content of strain NM-6 could achieve to 0.43% and 1.523mmol/L, and would be improved 59.3% and 25.3% than before.Through single factor experiment and orthogonal experiment got the optimum process conditions of fermented red bean milk:the concentration of red bean milk was 5%,the eythritol addiction was 1.5%, the inoculum of strain NM-6 was 4%, the fermentation time was 16h,the fermentation temperature was 37℃.In the optimum technological conditions the free amino nitrogen content of sour milk could achieve to 1.524mmol/L.At last the best complex stabilizer addiction (pectin:CMC=1:1) was 0.10% when the eccentricity of product was the least and the stable effect was the best.To analysis the 16SrDNA sequence of strain NM-6, the total length of gene sequences were 1461bp, at last the strain NM-6 was identified as Pediococcus acidilactici.