Quality Parameter Assessment in Scented Rice Cultivars

Abstract

Rice quality is a complex trait comprising many physicochemical characteristics. Consumers base their concept of quality on the grain’s appearance, size and shape of the grain, behavior upon cooking, taste, tenderness, and flavor of cooked rice (Table 3.1). Appearance of milled rice is important to consumers. Thus, grain size and shape are the first criteria for rice quality that breeders consider in developing new varieties (Adair et al. 1966). Preferences for grain size and shape vary with consumers as some ethnic groups prefer short bold grains, while medium and long slender grains are preferred by others. The cooking and eating qualities of rice are valuable properties, especially in Asia, where it is the most important food. These qualities are largely determined by the properties of starch that makes up to 90 % of milled rice. Gelatinization temperature, amylose content, and gel consistency are the important starch properties, which influence cooking and eating characteristics. Gelatinization temperature determines cooking time of rice. Amylose content correlates negatively with taste panel scores for cohesiveness, tenderness, color, and gloss of rice and hence predicts the cooking and processing behavior of rice (Juliano 1979). The texture of rice varies on the basis of gel consistency in high amylose content rice. In general, rice with soft to medium gel consistency, intermediate amylose content, and intermediate gelatinization temperature is a preferred level for the consumers (Khush et al. 1979). However, the cooking quality preferences are known to vary within the country, within the ethnic groups, from one country to another, and within different geographical regions (Juliano et al. 1964). Extra elongation on cooking is a highly desirable trait in high-quality rice like basmati (Table 3.2, Fig. 3.1). Thus, these parameters play a crucial role in rice quality.