Effects of endogenous anthocyanins on appearance, bioactivity, and starch digestibility in black rice mutants

In addition to starch, rice contains a variety of nutrients, including anthocyanins found in black rice, which are associated with various health benefits. However, systematic research on the effects of endogenous anthocyanins on starch properties of black rice is lacking. This study employed a series of mutants with varying anthocyanin contents derived from a single parent to meticulously delineate their physical characteristics, biological activity, and starch properties. The findings revealed a positive correlation between seven individual anthocyanins in black rice and color parameters, phenolic and flavonoid contents, and antioxidant activity. Moreover, endogenous anthocyanins effectively inhibit the digestibility of starch after cooking, thereby reducing the eGI value. Additionally, anthocyanins were observed to alter the pasting and thermal properties of starch. These findings may provide insights into the potential applications of novel rice-based foods with enhanced biological activity and a lower estimated high glycemic index (eGI), and facilitate the development and application of rice varieties with high anthocyanin content. • Endogenous anthocyanins (EAs) do not affect the main nutrients in black rice. • High-anthocyanin mutants exhibit elevated levels of antioxidant activity. • The EAs in black rice reduce the rate of starch digestion. • The EAs in black rice alter the pasting and thermal properties of starch.