A comprehensive evaluation of appearance stability during rice storage based on analytic hierarchy process

Abstract

This study aimed to accurately recognize rice varieties with superior storage stability for grain appearance and clarify their characteristics. Thirty-four rice varieties were subjected to 1 year of storage to monitor changes in grain appearance. The results showed that head milled rice appearance deteriorated after storage, as evidenced by an average decrease of 4.60 % in lightness and 15.8 % in transparency, and an average increase of 32.4 % in chalkiness. Furthermore, appearance storage stability of head milled rice was evaluated using an analytic hierarchy process based on scores for lightness, chalkiness degree, and transparency. A judgment matrix was created, determining their respective weights of 0.614, 0.269, and 0.117, respectively. Using normalization methods, cluster analysis, and principal component analysis, rice varieties were categorized into three types: superior, intermediate, and inferior storage stability. Correlation analysis (P < 0.05) showed that appearance storage stability was significantly and positively correlated with grain weight and width, whereas it was significantly and negatively correlated with superoxide dismutase (SOD) activity. Furthermore, compared to varieties with inferior storage stability, rice exhibiting superior stability showed a 14.9 % increase in grain weight, 7.63 % increase in width, and 8.51 % decrease in SOD. Therefore, primary characteristic for rice varieties with superior appearance storage stability is their higher grain weight and width, and lower SOD activity.