本研究以動力學方程式,分析台農66 號甘藷在室溫儲存時,β -carotene (β- 胡蘿蔔素) 含 量的降解現象。台農66 號甘藷是台灣特有的甘藷品種,單位產量達48.0 ton/ha,因為台農66 號 甘藷含有豐富的β -carotene,含量換算成乾重約為1.14 mg/g,因此台農66 號甘藷可以表現出生 理機能性。目前台灣市場上市售甘藷多以室溫方式儲存,但室溫不利於甘藷的保存,除了發芽問 題之外,β -carotene 含量會在室溫儲存時發生降解,而降解速度可用動力學方程式分析。台農66 號甘藷中所含的β-carotene 主要是all-trans β-carotene,若使用室溫儲存的方式來儲存,當儲存 至21 天,會有58.8% 的β-carotene 降解,若繼續儲存到105 天,大約會有96.5% 的β-carotene 降解。以室溫條件儲存台農66 號甘藷時,其β-carotene 的降解現象符合一級反應特性,反應常 數為0.034 (day-1),本研究成果可供甘藷相關業者,進行台農66 號甘藷儲存處理與後續加工時的參考。
The influence of ambient condition on the β-carotene content of TNG66 sweet potatoes during storage was studied. TNG66 sweet potatoes are an original Taiwanese sweet potato cultivar. The annual yield of TNG66 sweet potatoes is 48.0 ton/ha. Because they contain significant amount of β-carotene (1.14 mg/g, on dry weight basis), TNG66 sweet potatoes have excellent bio-functionalities. On the current market, TNG66 sweet potatoes are generally stored under ambient condition. However, the ambient condition should not be used to store sweet potatoes. The warm temperature resulted in spouting and causing the degradation of active components. The degradation reaction was analyzed by a kinetic model. TNG66 sweet potatoes mainly contained all-trans β-carotene. When TNG66 sweet potatoes were stored under ambient condition, 58.8% β-carotene degraded after 21 days. In addition, 96.5% β-carotene degraded after 105 days. The kinetic model of β-carotene degradation was first order. The reaction rate constant was 0.034 (day-1). The results of this study were useful for sweet potato manufacturers when storing and processing TNG66 sweet potatoes.