Abstract:

Stabilized treatment was conducted on rice bran through microwave. The effects of the moisture content of rice
bran, microwave processing time and power on residual peroxidase activity of rice bran and acid value changes after 30 days
of　storage were examined. An orthogonal array experimental design was applied to optimize the microwave processing
parameters. The results indicated that when the thickness of the material layer was 1cm, the optimal microwave conditions
were as follows: moisture content, 28%; processing time, 90 seconds; and microwave power, 600 W. Under the optimal
conditions, the residual peroxidase activity was 1.9%, which was lower than the maximum permissible value of 5%. After 30
days of strorage at 37 ℃, the fatty acid value was 17.5 mg KOH/g, far lower than that of the control group (212.0 mg KOH/g).
At the same time, gas chromatography-mass spectrometry (GC-MS) analysis showed that microwave treatment had little
effect on the main fatty acids of rice bran. Therefore, microwave treatment can largely improve the stability of rice bran and
is available for the extraction of rice bran oil.

Key words: rice bran, microwave, stabilization treatment, fatty acid composition