预处理方式对米糠酵素品质的影响

Effects of Pretreatment Methods on the Quality of Rice Bran Ferment

为研究经超声、微波、焙烤三种方法处理米糠对发酵后米糠酵素品质的影响,本文以米糠为原料,乳酸菌和酵母为发酵菌种,首先考察了发酵时间、发酵温度、接种比例对米糠酵素中γ-氨基丁酸(GABA)含量和pH的影响,并通过正交实验确定米糠酵素的最优发酵条件;采用超声、微波、焙烤不同工艺条件处理米糠原料,比较不同预处理方式对米糠酵素品质的影响。结果表明:经验证试验确定米糠酵素最优发酵工艺条件为:发酵时间24 h、发酵温度30℃、乳酸菌与酵母接种比为1:2(接种量为3%)。超声预处理方法可以显著提高米糠酵素中GABA含量(P<0.05),微波对GABA含量影响不显著(P>0.05),焙烤显著降低GABA含量(P<0.05);米糠在超声功率240 W处理24 h后,米糠酵素中GABA含量为2.61 g/L,是未处理的1.85倍。本文初步探讨了不同预处理方式对米糠酵素品质的影响以期为后续制备米糠酵素提供一种新思路。

In order to study the effect of the treatment of ultrasound,microwave and baking on the quality of rice bran ferment after fermentation,rice bran was used as raw materials,Saccharomyces cerevisiae and Lactobacillus plantarum were used as fermentation strains.Based on the effects of fermentation time,fermentation temperature,and inoculation amount on the content ofγ-aminobutyric acid content and pH in rice bran ferment,orthogonal experiments were used to obtain optimal conditions for rice bran ferment.Then,the rice bran raw materials were processed under different process conditions of ultrasound,microwave and baking,and the effects of different pretreatment methods on the rice bran ferment were compared.The results showed that the optimal fermentation conditions for rice bran ferment were as follows:fermentation time 24 h,fermentation temperature 30℃,and the inoculation ratio of L.plantarum to S.cerevisiae was 1:2(3%compound fermentation strain).Ultrasonic pretreatment method significantly increased the content ofγ-aminobutyric acid in rice bran ferment(P<0.05),microwave had no significant effect on the content ofγ-aminobutyric acid(P>0.05),baking significantly reduced the content ofγ-aminobutyric acid(P<0.05).Rice bran was treated with ultrasonic power 240 W for 24 h,the content ofγ-aminobutyric acid in rice bran ferment was 2.61 g/L,which was 1.85 times than that of untreated rice.This article preliminary discusses the effect of different pretreatment methods on the quality of rice bran enzyme in order to provide a new idea for the subsequent preparation of rice bran ferment.