Abstract:

In order to obtain wheat germ oil with the lowest content of nonhydratable phospholipids (NHP), microwave
was employed to pretreat wheat germ in this study. An L9(34) orthogonal array was designed to optimize pretreatment
conditions. The independent variables studies were initial moisture content of wheat germ, microwave irradiation time and
power The response was NHP content. The optimal pretreatment conditions were established as follows: initial moisture
content of wheat germ, 26.0%; microwave irradiation time, 3 min; and microwave power, 480 W. The maximum yield of
wheat germ oil of 9.22% was obtained under the optimized pretreatment conditions, which was higher than those obtained
from the control (6.21%) and roasted samples (1.09%). The NHP contents in oil of wheat germ treated with microwave and
baking were 0.087 and 8.04 mg/g, respectively, whereas NHP content in control was 15.22 mg/g. In conclusion, microwave
pretreatment of wheat germ could significantly reduce the content of NHP and improved wheat germ oil yield.

Key words: wheat germ, microwave pretreatment, nonhydratable phospholipids