Abstract: 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.

Key words: brown rice, germination, endogenous enzyme, nutritional ingredient, correlation