Study on using lactic acid bacteria improve the content of soluble protein and total phenol of wheat germ and its ability to inhibit oxidation of liposome

On the basis of single factor trials,optimized fermentation conditions of wheat germ fermented by lactic acid bacteria were investigated using orthogonal experiment. The content of water-soluble protein and total polyphenols in fermented wheat germ was used as indicators in these trials. And the ability of fermented wheat germ to inhibit liposome oxidation was investigated. The results showed that the content of soluble protein and total polyphenols were significantly influenced by initial p H. The optimal conditions for the soluble protein content were indicated as initial p H5.0,vitamin B6 concentration 150 μmol/L,fermentation time 12 h and fermentation temperature 35 ℃. While the optimal conditions for the total polyphenols content were indicated as initial p H5.0,vitamin B6 concentration 100 μmol/L,fermentation time 36 h and fermentation temperature 35 ℃.The concentration of soluble protein and polyphenols in optimal conditions were 24.86 mg/m L and 0.876 mg/m L respectively,which increased by 1.74 times and 1.45 times respectively when compared with raw materials.Meanwhile,the ability of the water-soluble components of wheat germ in retarding liposome oxidation was increased by lactic acid fermentation with the inhibition rate of 45.5%. The results of ·OH scavenging capacity and Fe²⁺ chelating capacity showed that the ability of fermented wheat germ to retard liposome oxidation was related with its ·OH scavenging capacity.