An Efficient Method for Evaluating the Palatability Deterioration During Storage in Rice

摘要

This study was conducted to establish an efficient selection method for breeding highly palatable rice cultivars with less deterioration in palatability during storage. The palatability of the rice stored at room temperature for one yr (old rice) negatively and significantly correlated with the content of free fatty acids in the polished rice and the hardness/adhesion ratio (H/-H ratio) of the cooked rice. Thus, we examined the correlation coefficients of the content of free fatty acids and the H/-H ratio for the old rice and rice stored in a stability-testing chamber (STC) kept at 40°C and relative humidity of 95% for various periods (10, 20, 30 and 60 d). The highest correlation coefficient was observed between the values in the old rice and those in the rice stored in the STC for 30 d. The palatability of the old rice did not correlate with the content of free fatty acids after a 30-d stored in the STC, but negatively and significantly correlated with the H/-H ratio after a 30 d stored in the STC. These results show that we can efficiently evaluate the palatability deterioration during storage in rice by measuring the H/-H ratio of the cooked rice after the stored in the STC for 30 d. The content of the free fatty acids is an effective indicator of palatability deterioration in the old rice, but that in the rice stored in the STC for 30 d is not.