Author：Yung-Chang Lai^1,3, Wayne C. Liao² and Che-Lun Huang¹

Abstract：

    Sweet potatoes have been used to feed animals. However, the trypsin inhibitor of sweet potatoes prevents animals from metabolizing proteins, and that reduces the practical application of using sweet potatoes as animals’ food. Thus, previous studies recommended selecting sweet potatoes with lower trypsin inhibitor activity for food applications. The trypsin inhibitor activity of Taiwanese sweet potato varieties (lines) was analyzed in this study. For animal feed sweet potatoes, the trypsin inhibitor activity of TN18, TNG17, and TNG31 was higher than 70%. On the other hand, the trypsin inhibitor activity of TNG10, the most popular animal feed sweet potato variety in Taiwan, was approximately 52.6%. The influence of thermal processing including boiling, microwaving, and baking on the trypsin inhibitor activity of sweet potatoes was also analyzed in this study. The boiling treatment successfully reduced the trypsin inhibitor activity of sweet potatoes. However, some sweet potatoes retained partial trypsin inhibitor activity after boiling treatment. An experimental line named CYY99-68 had high yield (66.12 ± 0.85 ton/ha) and low trypsin inhibitor activity (approximately 32.4%). Therefore, CYY99-68 was a good sweet potato variety for the purpose of animal feed.

Keywords: Animal feed sweet potatoes, Trypsin inhibitor activity, Thermal processing.

¹ Agricultural Research Institute, Chia-Yi Agricultural Experiment Station, 2, Min-Cheng Rd., Chia-Yi, Taiwan.
² Department of Nursing, Chang Gung University of Science and Technology, Chia-Yi, Taiwan.
³ Corresponding Author, Email: davidlai@dns.caes.gov.tw; Tel: 05-2771341.