糙米发芽过程中内源酶活力及主要成分的变化

目的：探讨糙米在发芽过程中内源酶活力和主要成分的变化规律及相关性。方法：以“早944”稻米为材料制备发芽糙米，在30℃下发芽培养72h，每隔12h对其内源酶活力和主要成分含量进行测定。结果：糙米内α-淀粉酶、β-淀粉酶、蛋白酶、谷氨酸脱羧酶、植酸酶等内源酶活力呈现上升趋势，发芽72h时酶活力分别达5.45U/g、3.78U/g、14.08U/g、9.72U/100g、3.44U/g；γ-氨基丁酸、还原糖、游离氨基酸含量呈现增长趋势，发芽72h时含量分别为237.05mg/100g、18.15mg/g、214.94μg/g；同时，总糖、粗蛋白和植酸含量呈现降低趋势，发芽72h时含量分别为44.16、9.59、1.99mg/g。结论：内源酶与其代谢的底物及代谢产物之间都存在显著相关性，部分内源酶与非内源酶代谢相关底物及产物之间亦存在显著相关性。糙米发芽72h后的营养价值高于发芽前，适宜用作新型糙米食品的生产原料。

Changes of Endogenous Enzyme Activities and Major Components in Brown Rice during Germination

Objective: To investigate the changes of endogenous enzyme activities and major components as well as their correlation in brown rice during germination. Methods: Z944 rice was used as the material to prepare germinated brown rice by incubating at 30 ℃ for 72 h. Analysis of endogenous enzyme activities and major components in germinated brown rice was conducted every other 12 h during germination. Results: The activities of α-amylase, β-amylase, protease, glutamic acid decarboxylase and phytase in germinated brown rice exhibited an upward trend and reached up to 5.45 U/g, 3.78 U/g, 14.08 U/g, 9.72 U/100g and 3.44 U/g, respectively at the end of the generation period. However, the contents of γ-aminobutyric acid, reducing sugars and free amino acids showed a tendency to decline and the corresponding final values were 44.16, 9.59 mg/g and 1.99 mg/g, respectively Conclusion: The activities of 5 endogenous enzymes investigated had a significant correlation with the contents of their metabolic substrates or metabolites, and some of them were also significantly correlated with non-enzyme metabolic substrates or corresponding metabolites. The nutritional value of 72 h germinated brown rice is higher than that of ungerminated brown rice and therefore 72 h germinated brown rice is suitable for the development of novel brown rice food products.