纤维素酶预处理糙米发芽工艺优化

Optimization of Brown Rice Germination Process with Cellulase Treatment

为解决发芽糙米蒸煮后口感差的问题,提出酶溶液浸泡糙米提供发芽条件的同时适当降解皮层粗纤维预处理工艺。研究酶浓度、酶解温度以及酶解时间对糙米发芽率及发芽糙米硬度的影响规律,采用二次旋转组合试验方法设计试验。并以GABA含量为考核指标,将酶预处理工艺与传统浸泡工艺进行了对比试验。结果表明:试验因素对糙米发芽率及发芽糙米硬度变化影响显著;酶预处理工艺优化参数组合为:酶浓度为0.4 mg/mL、酶解温度为33℃和酶解时间为110 min,在此条件下,糙米发芽率可达到传统浸泡处理的90%以上,其硬度降低14.1%。最优酶解条件下得到的发芽糙米GABA含量略低于未经酶浸泡得到的发芽糙米GABA含量。并通过扫描电镜分析证实了发芽糙米皮层粗纤维降解是其硬度下降的原因。

In order to improve the taste of the cooked germinated brown rice, the research of the pre - treating technology for cellulose -immersing brown rice was explored to provide conditions for germination and appropriate degradation of the cortex crude fiber. Influences of the enzyme concentration, the enzyme temperature and enzymolys- is time on the germinating rate of brown rice, and the variation of hardness were studied by quadratic regression rotary combination experiments. The GABA content of germinated brown rice was taken as the index for evaluation and the comparative test was carried out with traditional process of soaking and germination. The results showed that experi- mental factors had significant effects on the germinating rate of brown rice and hardness of germinated brown rice. And the optimum parameter combination in the germination rate of germinated brown rice was that the enzyme concen- tration being 0.4 mg/mL, enzyme temperature being 33 ℃, and enzyme time being 110 rain. Under such conditions, the germination rate of brown rice can reach up to higher than 90% of that soaking in a traditional way, and the hardness of germinated brown rice can be reduced by 14. 1%. The GABA content in germinated brown rice by the cellulase pretreatment is a little lower than that by traditional immersion. The cortex crude fiber degradation of germinated brown rice proved to be the reason for the decline of hardness with scanning electron microscope analysis.