1. Inst. of Quality and Standard for Agro-Products; Zhejiang Academy of Agricultural Sciences; Hangzhou; Zhejiang 310021 China
2. College of Biosystems Engineering and Food Science; Zhejiang Univ; Hangzhou Zhejiang 310058 China
3. Dept. of Population Medicine and Diagnostic Sciences; College of Veterinary Medicine; Cornell Univ; Ithaca NY 14853 U.S.A
4. Dept. of Biological and Agricultural Engineering; Univ. of Arkansas; Fayetteville AR 72701 U.S.A