Germination alters the bioactive compounds of pigmented and non-pigmented rice varieties in fresh and year-old stored seeds

This study assessed the effect of germination on bioactive compounds in fresh and one-year-old seeds of pigmented and non-pigmented rice varieties. Rice varieties had similar changes in bioactive compounds during germination. GABA and several phenolic acids increased 11.7 to 18.5 folds and 0.7 to 4.2 folds, respectively in germinating seeds. The vitamin E compounds, γ-tocotrienol and α-tocopherol increased by 23 to 35 % only in soaked seeds, but declined after seed germination. In the germinating seeds, higher levels of phenolic acids (e.g., protocatechuic acid, 0.5-fold higher) and some compounds of vitamin E (e.g., γ-tocotrienol, 0.4-fold higher) were observed in the pigmented rice compared to the non-pigmented line, in accordance with antioxidant activity. Additionally, one-year-old seeds exhibited the same increases in bioactive compounds as the fresh seeds. We conclude that the seeds of the pigmented variety have the potential as a raw material for germination in the rice industry.