Biochemical characterization and potential of red rice as functional food

Abstract It is the need of hour to supply functional nutraceuticals through the staple food not only to feed the exponentially increasing global population, but to also provide wholesome nutrition. White rice may have higher content of important nutrients but it is devoid of antioxidant properties majorly due to lack of pigmentation. Therefore, red rice could be a better alternative for the sizable population, who are dependant on it as their primary source of food. In this paper we studied twenty red rice genotypes, with regard to their biochemical and cooking quality attributes, to unravel their nutritional richness. The important quality parameters like anthocyanin pigments (anthocyanidins and leucoanthocyanidin) were found in range of 5252.71 to 5731.52 (µg/g) and Fe content ranged between 15.11 and 17.79 (mg/100 g). Surprisingly, the total distribution of antioxidant IC 50 (24.70–28.16 µg/ml) of the red rice varieties was not only reflective of the anthocyanin content but also of the total phenol (strong positive correlation with antioxidant, correlation coefficient 0.728**) and flavonoid content. Furthermore, the in-vitro digestion of red rice starch revealed its slow digestibility indicating presence of resistant starch (15.6 mg maltose released/100 mg). In support of validation for such important traits, the study of molecular Simple Sequence Repeat markers hinted at a good diversity of important nutritional attributes like grain proteins, Zn and Fe. Thus, these may serve as a potential source of lines for the purpose of breeding and varietal development programme of red rice. The investigated red rice varieties can replace white rice as a comparatively more nutritious food due to their superior functional effects and higher nutraceutical content. We are reporting the NVSR lines for low water uptake as well decrease in cooking time unlike other red rice varieties. SSR marker RM 206 may be successfully explored for MAS (marker assisted selection) linked with both the traits namely iron content and kernel breadth in NVSR lines.