Abstract
The relations between sulfhydryl contents and rheological properties of cooked rice were investigated with using farinograph. The consistency in farinogram increased with the addition of oxidizing agent, which meant that the hardness of cooked rice increased when oxidative transition of sulfhydryl groups to disulfide groups occured.
It is generally accepted that the hydrogen sulfide is one of the indispensable component of cooked rice aroma, and also was reported that the hydrogen sulfide, in general, generated from the sulfhydryl groups of protein. The amount of hydrogen sulfide in the cooked volatile of rice was found, in this report, richer in the rice stored at 5°C than stored at 40°C.
Therefore, it is conceivable that the decrease of sulfhydryl groups during rice storage contributes to both texture deterioration and aroma change.
Considering the interaction among lipid, protein and starch, the mechanism of storage deterioration of polished rice was discussed and provisional scheme was presented in this report.
