Abstract
“Hayadakimai” is a newly developed rice product prepared by steam treatment. It is served after brief cooking without pretreatments such as soaking and washing and also shows the taste similar to regularly cooked rice. Physico-chemical and rheological analyses, such as water absorption, SEM, X-ray diffraction and viscosity analysis, have been carried out to characterize this new product. The rice showed high water absorption, similar viscometric properties, but lack the crystalline starch structure. The remarkable reduction of cooking time in “Hayadakimai” is caused by its high water absorption, which, in turn, resulted from the partial gelatinization of starch on the grain surface of “Hayadakimai” and from the destruction of crystalline structure of starch granules even in the inside depth of the grain. It was suggested that changes in cell wall structure in endosperm cells might also affect the morphological change observed with the “Hayadakimai” grain.
