It is important to clarify the effects of starch fine structure and protein components on the eating quality of indica rice. In this study, seven indica rice varieties with similar apparent amylose content (AAC) and protein content (PC) but different sensory taste values were selected and compared systematically. It was found that except for AAC and PC, these varieties showed significant differences in starch molecular structure and protein components. Compared with rice varieties with a low sensory taste value, varieties with a higher sensory taste value showed significantly lower amylose and higher amylopectin short chains (degree of polymerization 6–12) content; the protein component showed that the varieties with good taste value had higher albumin and lower globulin and glutelin content (p < 0.05). Rice varieties with lower AC, globulin, and glutelin content, as well as a higher content of albumin and amylopectin short chains, resulted in a higher swelling factor, peak viscosity, breakdown value, and ratio of hardness to stickiness, in which condition cooked rice showed a higher sensory taste value. Moreover, this study indicated that rice varieties with a higher content of albumin and amylopectin short chains were conducive to the good appearance of cooked rice. This study lays the foundation for the taste evaluation of good-tasting indica rice.

Polyphenols, a major bioactive constituent in rice grain, require processing and digestion before being absorbed by human body. Free and bound phenolics, flavonoids and their antioxidant activities in non-pigmented, red and black rice after cooking and INFOGEST digestions of oral, gastric and intestinal phases were investigated. It showed that cooking caused great losses of polyphenols and antioxidant activity. Free ferulic, isoferulic and p-coumaric acid in most rice were highest at intestinal phase (p < 0.05). Bound ferulic acid in three colored rice, bound p-coumaric acid in black rice and catechin in red rice were higher at oral and/or gastric phase. After cooking, total flavonoids of non-pigmented and pigmented rice were highest at intestinal and gastric phase, respectively. Cyanidin-3-O-glucoside, peonidin-3-O-glucoside and quercetin peaked at intestinal phase in black rice. It suggested that black rice has a greater potential to be used in meal balance and functional product development.