|關鍵字： 甘藷；熱處理；貯藏；Sweet potato；Heat treatments；storage
|摘要： 甘藷長久性貯藏在國外已經很普遍，國外都是在特定的溫濕度冷藏庫中進行貯藏，而台灣因為貯藏期間的高腐爛率因此較少見。因此本研究目的為使甘藷經過適當的熱處理而後進行貯藏。本研究所使用的熱處理方法，包括熱風處理、熱水處理以及蒸汽處理預防貯藏期間的腐爛，並且實際量測甘藷表面深度5 mm處的溫度，並使用商業軟體COMSOL Multiphysics模擬甘藷在熱處理的加熱過程中，深度5 mm處的溫度與實際加熱溫度相近，以此模擬推測甘藷表面溫度。熱處理後的甘藷在13~15℃、相對濕度85~100%下進行冷藏，經由統計分析比較貯藏30天與60天之腐爛率。在此冷藏貯藏期後，由變異數分析結果指出冷藏貯藏比室溫貯藏腐爛率低，在統計上具有顯著的差異(p<0.05)。冷藏貯藏中的甘藷容易產生鬚根，腐爛率也較高。而在冷藏貯藏中，各熱處理者皆比對照組腐爛率低，在統計上也具有顯著的差異(p<0.05)，且在蒸汽處理下的甘藷外觀顏色雖然較深但仍可以接受。本實驗結果顯示，甘藷於冷藏前進行熱處理在貯藏30天內是俱有商業應用的可行性，60天的貯藏因為甘藷樣本來源有些已經受到感染而較容易腐爛，所以必須更加嚴選無受損及感染的甘藷，達成貯藏60天的商業可行性。It is very general abroad that sweet potato are stored in cold storage. However, in Taiwan, cold storage of sweet potato is rarely seen because of highly decay loss. Therefore, the purpose of this study was concentrated on heating treatments to decrease decay of sweet potato during cold storage. The methods of this study were to use the heat treatments included hot air, hot water and steam to prevent decay. We measured the temperature in 5 mm depth of the surface on sweet potato in heating treatments and also used COMSOL Multiphysics to simulate the process and to predict surface temperature that was undetectable during heating process to insure the effeteness of heat treatments. After heating treatments, sweet potato were stored in cold rooms at 13~15℃ and 85~100%. After storage of 30 and 60 days, decay rates were compared by using statistical analysis program ANOVA. The results showed the decay rates in cold rooms were significantly lower (p<0.05) than that in room temperature. Sweet potato became more decayed and produced fibrous roots in non-treated control during cold storage. Control treatments had much more decay than heat treatments and were also significant (p<0.05) but difference between hot water and steam treatments were insignificant. Steam treatments caused sweet potato became more brownish but still acceptable. Our results indicate that 30 days storage of heat treated sweet potato in cold storage is commercially applicable and the storage life might extent to 60 days if healthy roots are selected.