Characteristics of Glutinous Rice Fractions and Improvement of Yoogwa Processing by Microparticulation/Air-classification

찹쌀의 초미세분쇄/공기분급 특성과 유과제조공정 개선

Glutinous rice was microparticulated and air-classified at different air classifying wheel speeds (ACWS) of 20,000 rpm and 15,000 rpm in a Turboplex classifier. The starch was concentrated to a coarse fraction and the protein was shifted to a fine fraction. The degree of starch damage of the coarse fraction was comparable to that of traditionally soaked glutinous rice. Yoogwa(Korean cracker) made from the fractions of $ACWS\;15,000{\sim}20,000\;rpm$ and below ACWS 15,000 rpm was very comparable to that made by the traditional method in degree of puffing, hardness and internal structure. It was also confirmed by the sensory evaluation, indicating that the microparticulation/air classification technology could be applied to produce raw material of Yoogwa. The developed noble process could exclude the long soaking step in the traditional Yoogwa process and reduce the pretest time remarkably.

초미세분쇄한 찹쌀분말을 공기분급휠속도(ACWS, air classifying wheel speed) 20,000 rpm과 15,000 rpm으로 공기분급하였을 경우 ACWS의 증가에 따라 입자의 크기는 감소하였으며, 성분조성중 단백질, 지방, 회분은 증가한 반면 전분질은 감소하였다. 조분획의 전분손상도가 전통적인 침지방법으로 제조된 찹쌀분말의 전분손상도와 비슷하였다. 회수된 각 분획으로 유과를 제조하여 이를 전통적인 방법으로 제조한 유과와 비교한 결과, $15,000{\sim}20,000\;rpm$ 분획과 15,000 rpm 이하의 분획으로 제조한 유과는 전통적인 방법으로 제조한 유과와 팽화율, 경도, 기포수 등의 품질요인에서 유의차가 없었으며 관능검사 결과도 동일하게 나타났다. 따라서 이 분말소재를 이용할 경우 전통적인 유과제조공정중 수침공정을 생략할 수 있었다.