Characteristic of the smell of the low protein cooking rice, and relationship of taste

Abstract

　Sufficient energy and low protein intake are essential for dietetic treatment of patients with renal disease. Low-protein rice used for such dietetic treatment has issues in terms of taste and smell unlike general non-glutinous rice. However, there are only few research reports regarding the smell of low-protein rice.

　In the present study, we conducted physicochemical analysis and sensory evaluation of several types of rice when boiled with adjusted protein contents by using a gas chromatography mass spectrometer (GC/MS) and a smell identification device, determined characteristics of smells, and examined the correlation between smells and deliciousness of these types of rice.

　Concentration of hexanal, which is an odorous component of boiled rice with adjusted protein contents, was unrelated to the protein contents in the rice. Boiled rice with adjusted protein contents had a strong odor from a sensory viewpoint and was judged as inadequate in terms of deliciousness. The survey results indicated that the contents of hexanal or aldehyde series had negative effects on both smell and taste of the boiled rice with adjusted protein contents and, consequently, had a negative effect on deliciousness as well.