Study On The Preparation Of Polypeptide Accumulation In Germinated Brown Rice And Application In Yogurt

The variations of the peptide content in germinated brown rice with different components of the culture and germination conditions were studied with Heilongjiang widely grown locally rice as raw material. By optimizing the culture medium composition and culture conditions, the most favorable process paramenters were obtained. The coefficient of compare changes in the chemical compositions and bioactive compounds of brown rice and germinated brown rice. Then, we studied the physicochemical property of germinated brown rice accumulating peptides. Process conditions of germinated brown rice of accumulating peptides yoghurt were optimized. All the results were as followed:1. On the basis of the single factor, determined the impact of different concentrations of metal ions and auxin on peptide enrichment in germinated brown rice by Box-Behnken response surface methodology. The results showed that the optimal concentration of GA3, CaCl2, NaCl and MnSO4 in the culture solution were 41.37μmol/L, andl.63,3.61,1.54mmol/L, respectively. The polypeptide content in germinated brown rice cultured under these conditions was 8.19mg/g, which was 2.21-fold (3.72mg/g) and 2.57-fold (3.19mg/g) higher than the control and non-germinated brown rice, respectively.2. The optimum technological conditions of germinated brown rice were as ofllows: soaking temperature25℃, sokaing time16h, germination temperatuer34℃, germination time 28h. The highest peptides content of geminated brown rice through above conditions was 9.32mg/g, which was 2.92-fold (3.19mg/g) higher than non-germinated brown rice.3. After germinating of brown rice, the content of starch and its components declined; The transmittance and retrogradation stability of the starch paste enhanced. Geelatinization temperature and freeze-thaw stability declined. The results showed that the germination precess improved to some extene on the physical and chemical properties of brown rice starch.4. The germinated brown rice yoghurt was processed by liqueafetion, saccharification and lactic acid fermentation with germinated brown rice as raw material. The optimum technological conditions for germinated brown rice saccharification were:0.6% saccharifying enzyme, saccharification temperature 65℃, saccharification time 4 hours. After various experiments, the optimized formula of yoghurt was identified as followed:germinated brown riee:barley(2:1),mix rice 8%, non-fat milk powder 7%, CMC-Na 0.05%, xanthan gum 0.05%, sucrose esters 0.08%, Inoculum size 5%, fermented for 7h at 42℃. The polypeptide content in germinated brown rice yoghurt was 1.23mg/100mL.