Abstract

Gels of rice starches isolated from jinmibyeo, llpoombyeo and Dongjinbyeo were prepared with $60{\sim}65%$ water content (based on the total weight) and stored at $-18^{\circ}C,\;4^{\circ}C,\;20^{\circ}C,\;30^{\circ}C,\;and\;37^{\circ}C$ for 6 days. The effects of varieties, water content and storage temperature on the degree of retrogradation (DR) of gels were measured by ${\alpha}$-amylase-iodine method. DRs of rice starch gels increased rapidly during the initial stage of storage, but slowly after that. DRs were highest with 60% water content and lowest with 65% water content at any storage temperature. Regarding the storage temperature, DRs of gels increased in the following order : $4^{\circ}C>20^{\circ}C>30^{\circ}C>37^{\circ}C>-18^{\circ}C>$. As the storage temperature was increased, DR per $10^{\circ}C$ increased above refrigerated temperature decreased in the following order : jinmibyeo>llpoombyeo>Dongjinbyeo.

진미벼, 일품벼와 동진벼의 전분을 분리하여 수분함량이 $60{\sim}65%$인 전분겔을 제조하고 $4^{\circ}C,\;20^{\circ}C,\;30^{\circ}C,\;and\;37^{\circ}C,\;-18^{\circ}C$온도 조건에서 6일간 저장하면서 ${\alpha}$-아밀라아제법으로 노화도 변화를 측정하였다. 쌀전분겔의 노화도는 품종이나 전분겔의 수붐함량과 저장온도에 관계없이 저장초기에 급격히 증가하였으며 그 이후에는 완만한 증가를 보였다. 수분함량에 따른 노화도는 60% 전분겔이 가장 높고 65% 겔이 가장 낮았다. 저장온도의 경우, 전분겔의 노화도는 $4^{\circ}C>20^{\circ}C>30^{\circ}C>37^{\circ}C>-18^{\circ}C>$.의 순으로 낮아졌으며, 냉장온도 이상에서 저장온도 $10^{\circ}C$ 증가에 따른 노화도의 감소는 진미벼>일품벼>동진벼 순이었다.

Keywords

• rice starch gels;
• degree of retrogradation;
• water content;
• storage temperature