- 期刊
加熱時間對苦茶油品質與氧化穩定性之影響
Effect of Heating Time on the Quality and Oxidation Stability of Camellia brevistyla Seed Oil
摘要
油茶為全球四大木本油料植物之一，其種子壓榨所得之油脂（亦稱苦茶油）含有豐富的單元不飽和脂肪酸，具減緩腸胃不適及心血管疾病等保健功效，廣受亞洲地區消費者之重視。坊間對苦茶油的烹調方式多建議短時間低溫使用，但亦有「苦茶油的冒煙點高達220℃，適用於高溫烹調」之說法，然而，有關高溫烹調對苦茶油品質影響之文獻甚少。本研究取短柱山茶（Camellia brevistyla，俗稱小果油茶）種仁以螺旋榨油機壓製苦茶油，苦茶油於180℃連續加熱24 h，每8 h取一次油樣，分析油脂之脂肪酸、顏色、總極性物質、酸價及氧化穩定性等性質之變化，並與市面常見之2種壓榨種子油－亞麻油與葵花油進行比較。試驗結果顯示，苦茶油經180℃加熱後，苦茶油呈脂肪酸含量下降、油脂顏色先變淡後轉深黃、總極性物質含量及酸價上升、油脂氧化穩定指數下降之趨勢。相較於亞麻油與葵花油，苦茶油因單元不飽和脂肪酸比例較高故較穩定，其油脂氧化穩定指數亦較高，且在高溫使用下，油脂劣化程度較低。由本試驗得知，苦茶油、亞麻油及葵花油三種螺旋壓榨之種子油的品質在180℃高溫下皆隨加熱時間增加而下降，唯苦茶油含油酸比例較高故具較佳之油脂氧化穩定性，使其在高溫下劣化程度較低。
並列摘要
The Camellia family is one of the four famous woody oil plants. The oil pressed from camellia seeds, known as camellia seed oil, is rich in monounsaturated fatty acids. It also provides various benefits to health, such as relieving stomachache and preventing cardiovascular diseases. As a result, its popularity has increased in East Asia. The most common way of using camellia oil is to cook at low temperatures. It is also suggested that camellia seed oil is suitable for high temperature cooking since its smoke point is around 220° C. However, there was little study on the effects of high-temperature cooking on the quality of camellia seed oil. In this study, Camellia brevistyla seeds were pressed with a screw press. Oil samples were continuously heated at 180 °C for 24 h and taken every 8 h of heating and evaluated for the change of fatty acids, oil color, total polar compounds, acid value and oxidative stability during heating. There is also a comparison between camellia seed oil and other common cold-pressed seed oil-flaxseed oil and sunflower oil. The experimental results showed that as the increase of heating time the amount of fatty acids decreased, especially the unsaturated fatty acids. In addition, the total polar compounds content and acid value increased, and the oxidation stability index decreased in camellia seed oil during heating time. Compared with flaxseed oil and sunflower oil, camellia seed oil is more stable because of higher monounsaturated fatty acids proportion and the higher oxidative stability index. In addition, camellia seed oil at high temperature has lower degree of oxidative degradation. Therefore, it can be concluded that the quality of camellia seed oil, flaxseed oil and sunflower oil decreased as the increase of the 180℃ cooking time. While among the three pressed seed oils, high oleic acid camellia seed oil is more suitable and has lower degree of oxidative degradation at high temperature.