Yang Gu1,2, Peng Xu3. 1. Department of Chemical, Biochemical and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD, USA. 2. School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, China. 3. Department of Chemical, Biochemical and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD, USA. pengxu@umbc.edu.