# 현미 도정획분의 Lipoxygenase 활성

• Kim, Ki-Joong (Department of Food Science and Technology, Chonnam National University) ;
• Rhee, Chong-Ouk (Department of Food Science and Technology, Chonnam National University)
• 김기중 (전남대학교 식품공학과) ;
• 이종욱 (전남대학교 식품공학과)
• Published : 1997.02.01

#### Abstract

Lipoxygenase activity from brown rice varieties (Tongjinbyeo, Kumohbyeo and Kanchukbyeo) was investigated using spectrophotometric method. In all three varieties, there was an increase in the enzyme activity with the reaction time. Enzyme activity was tested at different concentration of the substrate. The $V_{max}\;and\;K_m$ values of Tongjin, Kumoh and Kanchukbyeo were 57.89, 19.85 and 31.38 units/mg protein and 0.054, 0.045 and 0.035 mM. The study of lipoxygenase activity at different pH levels showed that all the varieties had maximal activities around $pH\;7.0{\sim}7.6$. The enzyme activity and specific activity on milled fractions of different brown rice varieties, fraction II was superior to the other fractions and fraction IV was inferior to the other fractions. As the result of microwave heating for 0, 30, 60 and 90 sec, the enzyme activity and specific activity of all the varieties were decreased by the elapse of heating time.