Inactivation of PPO, POD and Colour Changes during Microwave Heating Treatment on Sugarcane
The brown color of raw sugar is mainly derived from the function of oxidases, mainly polyphenol oxidase (PPO) and peroxidase (POD), on cane juice during the sugarcane squeezing course. Effects of microwave heating treatment on the activity of PPO, POD and the color change of cane juice were investigated in this paper to explore the method of controlling enzymatic browning. It was demonstrated that the residual activity of PPO and POD decreased with the increase of microwave power (160α800W) and treatment time( 1~4 min). PPO was more sensitive than POD when exposed on microwave. However, no regular relationships were investigated among PPO activity, POD activity and the color of cane juice under various microwave treatments. Optimize processing conditions for lowest browning, which was under microwave power 549 W and treatment time 0.67 min, was obtained by applying response surface methodology (RSM) based on a three-factor-three-level Box-Behnken Design. It reveals that microwave heating process is a promising supplemental method to inactivate oxidases, thus reduce the color value of final sugar products and then improve sugar quality in sugarcane processing industry.
Keywords: Microwave; Polyphenol oxidase; Peroxidase; Cane juice Color, Response surface methodology
Corresponding author:
Dr. Shu-Juan Yu, professor, dean of College of Light Industry and Food Sciences, South China University of Tehchnology.
l Senior member of International Sugar Industry Technology Committee
l Senior member of China Academy of Food Science and Technology
l Senior member of China Academy of Sugar Manufacture
l Vice-chief editor of Modern Food Science & Technology
l Vice-chief editor of China Beet & Sugar
l EAB Member of Sugarcane and Canesugar
l EAB Member of Journal of Chinese Traditional and Western Medicine
l EAB Member of Process of Agricultural Products in China