Influence of Drying and Post-drying Conditions on the Head Rice Yield of Aromatic Rice

Jafar Hashemi, Md. Ashraful Haque, Naoto Shimizu, Toshinori Kimura


The effects of various drying temperatures, low final moisture, and post-drying duration, on fissure formation and head rice yield (HRY) reduction in aromatic short-grain rice, were investigated. The results of post-drying duration showed that most fissured kernels were produced within 12-h after drying process ceased and then became to stable within 24 h for all treatments. The whole kernel percentage of Kaori aromatic rice was reduced significantly (P < 0.01) when rice was dried at 50oC and 60oC for both standard and low final moisture content (FMC). For a given post-drying duration and conditions, low FMC treatments exhibited more HRY reduction than did standard FMC. It is well known that moisture gradient has much influence in producing fissure in kernels. In addition, increased difference between immediate storage temperature and drying air temperature augmented the increase in the percentage of fissured kernels (P < 0.01).

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