1Animal Health and Nutrition[EB/OL]. http://www. vets - plus. com/hoofcare. htm, Vets Plus, Inc.
2YOO WOOKJAE, KIM DAEHYUM, LEE DONGHOON, et al. Changes in respiration rates, cell wall components and their hydrolaseactivities during the ripening of ‘Whangkeumbae' pear fruit[ J ]. Journal of the Korean Society for Horticultural Science, 2002,43 ( 1 ): 43 -46.
3CASSANDRO AMARANTE, NIGEL H BANKS, SIVA GANESH. Relationship between character of skin cover of coated pears and permeance to water vapour and gases[ J ]. Postharvest Biology and Technology, 2001,21(3): 291 - 301.
4VELTMAN R H, LARRIGAUDIeRE C, WICHERS H J, et al. Poly- phenol oxidase activity and polyphenol content are not limiting factors during brown core development in pears[J]. Plant Physiol, 1999,154:697- 702.
5VELTMAN R H, SANDERS M G, PERSIJN S T, et al. Decreased ascorbic acid levels and brown core development in pears[J]. Physiol Plant, 1999, 107: 39-45.
6VELTMANRH, LENTHeRIC I, VAN dERPLASLH W, et al. Intemal browning in pear fruit ( Pyrus communis L. ) may be a result of a limited availability of energy and antioxidants[J ]. Postharvest Biology and Technology,2003,28(2): 295 - 302.