Abstract
The Korean rice, Nonglim # 6 was milled into brown rice and 92% polished one and packed with the kraft paper bags. The sample, bags were irradiated with the respective doses of 30, 50, 600 and 800 Krad and then were stored at $10^{\circ}C$ and 75% RH. Changes of fat acidity, amylase activity, viscosity of thus irradiated rice were examined during storage. The results were as follows. 1) Fat acidity increased slightly in the range of $30{\sim}50$ Krad but remarkably in the range of $600{\sim}800$ Krad. However, the rate of increase was low in comparison with the storage under the room temperature. 2) The amylase activity of both the low dose lot and the control decreased in the same rate during the storage. However the high dose lot had more remarkable decrease of the amylase activity from the beginning. 3) The viscosity by Brabender amylogram showed the slightly decreasing tendency in both the low $30{\sim}50$ Krad lot and the control lot of the polished rice powder during storage. On the other hand, the high dose lot of 600 or 800 Krad marked the similar decreasing rate but by far the lower values of the viscosity. 4) The results of the organoleptic test presented no differences between the low dose lot and the control lot, but the high dose lot and the control lot differed significantly only in the color.
경기도 김포지방에서 수확한 농림6호를 1970년 3월에 현미와 백미로 표준도정하여 kraft paper bag에 포장하고 Co-60 irradiator로 30, 50, 600 및 800 Krad의 조사한후 저온($10^{\circ}C$, 75% RH)에 저장하면서 fat acidity, amylase activity, 백미가루와 그 전분의 amylogram에 의한 viscosity 및 식미시험 등의 시험 결과는 다음과 같다. 1) Fat acidity의 증가는 $30{\sim}50\;Krad$ 조사미에 있어서 대조구에 비해서 근소한 차이였으나, $600{\sim}800\;Krad$ 조사구에서는 현저하게 증가하였고, 상온 저장에 비해서는 그 증가율이 낮았다. 2) Amylase activity는, $30{\sim}50\;Krad$ 조사구에서 대조구와 차이가 없고, 모두 감소경향이며, $600{\sim}800\;Krad$ 조사구는 그 감소경향이 현저하다. 3) Brabender amylogram에 의한 viscosity는 백미분의 경우 $30{\sim}50\;Krad$ 조사구는 대조구와 차이없이 저장중 약간 감소경향이고, $600{\sim}800\;Krad$ 조사구는 현저하게 그 viscosity가 감소하였다. 4) 식미시험 결과는 $30{\sim}50\;Krad$ 조사구가 대조구와는 차이가 없고, $600{\sim}800\;Krad$ 조사구는 색깔에서만 대조구와 유의차를 나타냈다.