Comparative proteomics and protein profile related to phenolic compounds and antioxidant activity in germinated Oryza sativa 'KDML105' and Thai brown rice 'Mali Daeng' for better nutritional value.

BACKGROUND: Brown rice (BR) and germinated brown rice (GBR) are considered as prime sources of carbohydrate and bioactive compounds for more than half of the populations worldwide. Several studies have reported on the proteomics of BR and GBR; however, the proteomic profiles related to the synthesis of bioactive compounds are less well documented. In the present study, BR and GBR were used in a comparative analysis of the proteomic and bioactive compound profiles for two famous Thai rice varieties: Khao Dawk Mali 105 (KDML) and Mali Daeng (MD).

RESULTS: The proteomes of KDML and MD revealed differences in the expression patterns of proteins after germination. Total phenolic compound content, anthocyanin contents and antioxidant activity of red rice MD was approximately 2.6-, 2.2- and 9.2-fold higher, respectively, compared to that of the white rice KDML. Moreover, GBR of MD showed higher total anthocyanin content and greater antioxidant activity, which is consistent with the increase expression of several proteins involved in the biosynthesis of phenolic compounds and protection against oxidative stress.

CONCLUSION: Red rice MD exhibits higher nutrient values compared to white rice KDML and the appropriate germination of brown rice could represent a method for improving health-related benefits. © 2017 Society of Chemical Industry.