1. School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and/ Product SafetySouth China Univ. of Technology Guangzhou 510640 China
2. School of Chemical Engineering and Energy TechnologyDongguan Univ. of Technology College Road 1 Dongguan 523808 China
3. College of Food Science and TechnologyNanjing Agricultural Univ. Nanjing 210095 China
4. Dept. of Microbial Pathogenesis, Dental SchoolUniv. of Maryland Baltimore MD 21201 USA