Adaptability of four-samples sensory tests and prediction of visual and near-infrared reflectance spectroscopy for Chinese indica rice

The potential of visual and near-infrared reflectance spectroscopy for evaluation of eating quality of Chinese indica rice and the adaptability of four-samples sensory tests (Shiten Shikenhou in Japanese) which were widely used in Japan to the sensory evaluation of Chinese indica rice were studied. Calibration equations were developed by using 60 Chinese indica rice samples. Another 30 Chinese indica rice samples were used to validate the equations. The determination coefficient (r2) for eating quality (aroma, appearance, brightness, taste, stickiness and hardness as independent variables) with four-samples sensory tests was 0.95, with corresponding standard error of prediction (SEP) of 0.25. The determination coefficient (r2) for eating quality with visual and near-infrared reflectance spectroscopy was 0.71, with SEP of 0.65. In addition, the mean values of eating quality for three rice samples obtained from four-samples sensory tests carried out in four cities of China had no significant difference (p = 0.05) with the corresponding predicted values. Thus, it was confirmed that four-samples sensory tests were suitable to evaluate eating quality of Chinese indica rice and visual and near-infrared reflectance spectroscopy could provide an objective and convenient way to evaluate Chinese indica rice.