1. Key Laboratory of Food Nutrition and Safety, Ministry of Education; Tianjin Univ. of Science and Technology; Tianjin 300457 China
2. Engineering Research Center of Food Biotechnology, Ministry of Education; Tianjin Univ. of Science and Technology; Tianjin 300457 China
3. Limerick Pulp and Paper Centre, Dept. of Chemical Engineering; Univ. of New Brunswick; Fredericton NB E3B5A3 Canada