Effects of the components in rice flour on thermal radical generation under microwave irradiation.
The relationships between radical generation under microwave irradiation and the components of various types of rice flour were investigated. Electron paramagnetic resonance (EPR) spectroscopy was used to characterize the radicals found in rice flour samples. The EPR spectra revealed that several types of radical (carbon-centered, tyrosyl and semiquinone) were localized in the starch and protein fractions of the rice flour. The signal intensity of the free radicals was observed to increase exponentially with increasing microwave power and residence time. The rice bran samples exhibited the greatest free radical signal intensity, followed by the brown rice samples and the white rice samples. This finding was consistent for both the native and the microwaved samples. The ratio of rice starch to rice protein also played an important role in the generation of radicals.
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Lufen
L
Lin
School of Applied Chemistry and Biological Technology, Shenzhen Polytechnic, Shenzhen 518055, China.
Luelue
L
Huang
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China. Electronic address: fandm@jiangnan.edu.cn.
Daming
D
Fan
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Bo
B
Hu
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Yishu
Y
Gao
Wuxi Huashun Minsheng Food Co. Ltd., Wuxi 214218, China.
Huizhang
H
Lian
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Jianxin
J
Zhao
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Hao
H
Zhang
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Wei
W
Chen
D005433:Flour; D007700:Kinetics; D008670:Metals / Q000032:analysis; D008872:Microwaves; D012275:Oryza / Q000737:chemistry*; D013696:Temperature
D008670:Metals
Microwave; Radicals; Rice