米糠发酵过程中脂肪酸组分及含量变化的研究

Changes of fatty acid composition and content in fermented rice bran

以新鲜米糠为原料,以料水比1:9(w:v)配成培养基,接入红曲(Monascus anka)M180和木耳(Auricularia auricular)A900,在30℃、200r/min摇床培养,培养时间分别为4d和7d。利用气相色谱法,对米糠发酵过程中脂肪酸组分及含量的变化进行分析。结果显示,米糠中主要脂肪酸为C16:0、C18:1、C18:2,占总脂肪酸的95.05%,C16:1、C18:1、C18:2等不饱和脂肪酸占总脂肪酸的80.09%,在红曲和木耳发酵过程中,脂肪酸含量一直呈下降趋势,总脂肪酸含量由最初的200.75mg/g分别下降至68.35mg/g和79.95mg/g,红曲M180比木耳A900利用脂肪酸速度快。发酵结束后,红曲发酵米糠和木耳发酵米糠中不饱和脂肪酸占总脂肪酸的比例分别为83.76%和80.84%,与发酵前相比,没有得到明显提高。利用红曲和木耳发酵米糠不能达到富集不饱和脂肪酸的目的,但可作为除去米糠中脂肪,抑制酸败的潜在途径。

Rice bran be added to pure water with ratio 1：9（w：v）was fermented using Monascus anka M180 and Auricularia auricular A900 for 5 days and 7 days respectively. The fermentation conditions were as 37 ℃, 200 r/min. The composition and content of fatty acids in the fermentation process was analyzed by Gas Chromatography. The results showed that the main fatty acids of the rice bran were C16：0, C18：1, C18：2, which were 95.05 % of total fatty acids. The unsaturated fatty acids mainly composed with C16：1, C18：1, C18：2 were 80.09% of total fatty acids in rice bran. The contents of fatty acid were decreasing in the fermentation process. The contents of total fatty acids in fermented rice bran with Monascus anka M180 and Auricularia auricular A900 decreased from 200.75 mg/g to 68.35 mg/g and 79.95mg/g respectively, and it indicated that the speed of utilization fatty acid of Monascus anka M180 was faster than Auricularia auricular. The proportion of the unsaturated fatty acids to total fatty acids increased to 83.76% and 80.84% and no obvious changes were obtained in two fermented rice bran compared with fresh rice bran. The unsaturated fatty acids of rice bran were not effectively accumulated using fermentation with Monascus anka M180 and Auricularia auricular A900, while it was potentially used to reduce fatty acid of the rice bran and then restrain the decay of rice bran.