Bioactive Compounds of Rice as Health Promoters
- Pp. 221-234 (14)Charu Lata Mahanta and Sangeeta Saikia
Rice (Oryza sativa L.) is one of the major cereal food crops in the world. It serves as a principal source of carbohydrate. Rice is also traditionally used for therapeutic purposes. The health promoting properties of brown rice has generated research interest. The health promoting properties are attributed to the bioactive compounds in the rice bran. These include vitamins, minerals, phenolic compounds, γ - oryzanol, tocopherols, tocotrienols, anthocyanins, phytosterols and dietary fibre. The concentration of bioactive properties is more in pigmented rice varieties. The bioactives in rice impart cholesterol reduction, anti-inflammatory, anti-tumor, anti-diabetic and anti-oxidative effects. Ferulic acid is the major phenolic acid in rice whose esters predominantly form γ-oryzanol and remains in the human blood stream for longer time than other phenolics thereby offering greater radical scavenging efficiency. The rice bran anthocyanin pigments contribute to the total phenolic and antioxidant properties of rice to a notable extent. The tocols also are potent antioxidants. Both in vivo and in vitro experiments have ascertained the effect of these compounds in animals and human beings. The bioactive potential of rice has been found to widely vary with variety, extent of polishing and processing. Cooking steaming, parboiling, fermentation and germination of rice result in marked changes in proportion and activities of different bioactive components. This chapter focuses on the bioactive compounds in rice, the potential health benefits of rice consumption, and processing effects on bioactivity.