(67(3):292-300)Influence of Storage Conditions of Camellia brevistyla Seeds on the Quality of Pressed Oils

本試驗將採收後立即乾燥至含水率6.5% 及12% 的台灣原生小果油茶 (短柱山茶，Camellia brevistyla) 種子，於-20、4、15℃環境下密封儲藏半年後榨油，將初榨油保存在密封的玻璃瓶中，於4℃儲放半年後開封，進行油脂的酸價、過氧化價、酚類化合物含量、還原力、維生素E 含量、油脂氧化安定性等分析。結果顯示，只要是無霉爛現象品質良好的油茶籽，經過半年儲藏後壓榨的油脂品質，其酸價、過氧化價等均可與鮮榨油相當，仍具有良好的食用品質。另仿效家庭使用習慣，將油脂放置於4℃冰箱，時常打開瓶蓋取用，再經過半年後檢測。結果顯示，含水率6.5% 的油茶籽，在4℃以下儲藏者的壓榨油品質較佳，而保存於-20℃的油茶籽壓榨油，不僅其內含酚類化合物及還原力的衰減最少，且具有最佳的氧化安定性，此時仍可達到壓榨苦茶油國家一級品質標準 (酸價 < 1.5、過氧化價 < 6)。 Camellia brevistyla is an indigenous Taiwanese camellia tree. After harvested, the seeds were dried immediately to a moisture content of 6.5% or 12%. Then, the seeds were stored at conditions of -20, 4, or 15℃ for 6 mo before pressed for oil. Following pressing, all the oils were sealed in glass bottles and preserved at 4℃ for 6 mo, and then subjected to analyses of acid value (AV), peroxide value (POV), phenolic content, reducing power, vitamin E content, and oxidative stability. Results indicated that all the oils were comparable to the freshly pressed ones, retaining good edible quality with the evaluation standards of AV < 1.0 and POV < 20 and the common food grade pressed oil standard. All these oil samples were continually kept at 4℃ for another 6 mo storage and then subjected to reanalyzing. During this period, occasionally opening of and withdrawing some oils from the bottles were conducted to imitate a common household habit. The results indicated that the oils from seeds with lower moisture content (6.5%) and stored at temperatures below 4℃ had a better quality. Besides, the oil from seeds stored at the lowest temperature -20℃ had the best oxidative stability, which still attained the first grade camellia tea oil quality as stipulated in the national standard (AV < 1.5, POV < 6). Its phenolic content and reducing power showed the least reduction from those at the moment when unsealing (6 mo ago)