A comparative study on physicochemical properties of rice and starch of white rice, black rice and black glutinous rice

Abstract

Rice is a staple food for Indonesians and Asians in general. It is rich in starch, a component that can be developed as a texture agent, filler, or raw material for edible films, encapsulation, or other products. The characteristics of the starch produced will determine its functional properties. This study aimed to characterize the physicochemical properties of rice and starch of white rice, black rice, and black glutinous rice. In this study, rice was extracted using an alkaline method to obtain rice starch. The processing of rice into starch can change some of its characteristics. A comparative study was also conducted on rice starch. The results showed that the starch contents of white, black, and black glutinous rice were 85.48; 86.67; and 83.56% (db). Black glutinous rice contains more amylopectin than black and white rice. Resistant starch in the rice fractions was greater than the amount of resistant starch in the starch fractions. Black rice contained anthocyanins of 323.85 mg/100 g, while the anthocyanins in black glutinous rice reached 219.35 mg/100 g. Although in very small amounts, anthocyanins were detected in black rice and black glutinous rice starch fractions. The starch fraction has much lower antioxidant activity compared to that in the form of rice. It appears on all types of rice. The peak viscosities of the starch of white rice, black rice, and black glutinous rice were 3627, 5448, and 5001 cP with pasting temperatures of 79.10°C, 80.60°C, and 80.90°C. Physicochemical and pasting properties of the rice fraction and the starch fraction from white, black, and black glutinous rice provide complete information to be used as a basis for the manufacture of food products.