|Abstract: ||氧化穩定性是油脂品質與保存期 (shelf-life) 的重要指標，氧化對於食用油脂的適口性、營養價值以及氧化毒性物質具有相當重要的影響性，目前油脂保存期的評估方法為加速保存試驗，此方法需要耗費大量人力與時間。本研究目的為開發以高溫通氧之方法使油脂在短時間內達到酸敗程度，藉以評估油脂氧化安定性與保存期限。本研究以大豆油探討不同溫度 (50℃、70℃、90℃) 下加熱並通以純氧對於油脂之影響，實驗分析過氧化價 (Peroxide value, POV)、茴香胺值 (p-Anisidine, p-AnV)、氣相層析質譜 (Gas chromatography–mass spectrometry, GC-MS)、傅里葉轉換紅外光譜 (Fourier transform infrared spectroscopy, FTIR)、極性化合物質 (Total polar compound, TPC)，以 POV = 30 meq/kg 作為酸敗指標，並以達酸敗時間點預測油脂保存期限，與 American Oil Chemists' Society (AOCS) 方法相比，以結果最相似之溫度作為高溫通氧之最適參數，再以此參數探討高溫通氧技術對於油脂 (大豆油、芝麻油、大豆芝麻調合油) 品質與安定性之相關性以及應用於調和油脂 (雞油調合油) 之開發。實驗結果顯示經不同溫度加熱後之油脂皆達酸敗程度時以GC-MS分析脂肪酸含量無顯著差異存在，在90℃，通氧量為1.5ml/min之條件下，大豆油可保存天數為266.7天，AOCS方法為255.67天，以90℃加熱與AOCS有最相之結果，因此以此做為高溫通氧之最適參數。在此參數下評估油脂安定性，由總體氧化程度結果顯示大豆油最差、調合油次之、芝麻油最佳，表示以此參數下對於評估油脂安定性具有一定的正確性。調合油脂開發應用之結果顯示，雞油經高溫通氧8小時 POV = 35.51 meq/kg，實驗以不同植物油增加雞油之安定性，在相同植物油以不同比例調和下，植物油比例愈高，其安定性愈佳，而芝麻油雖然具有良好的抗氧化能力，但基於芝麻油之價格較一般植物油高，因此將其作為添加劑添加於雞油-芥花調合油中，實驗結果以 50 % 雞油 + 45 % 芥花油 + 5 % 芝麻油為最佳安定性之調合油。本實驗開發高溫通氧技術不僅可以在短時間內評估油脂保存期限，亦可應用於油脂產品之開發以增加產品多樣性。|
Oxidation stability is an important indicator to determine the oil’s quality and shelf-life. Oxidation of oil is very important in terms of palatability, nutritional quality, and toxicity of edible oils. Generally, the current method of assessing the shelf-life of edible oil uses a stability test with the accelerated storage test. However, this method is time-wasting and labor-consuming. Therefore, the purpose of this thesis was to develop a rapid approach using high temperature (90℃) oxygen ventilation (HTOV) method to investigate the shelf-life of different edible oils in short term. In this study, soybean oil was the sample used to investigate the effects at different temperatures (50℃, 70℃, 90℃) against oil rancidity and oxygen ventilation. Moreover, the other parameters, such as peroxide value, fatty acid content, fourier transform infrared spectroscopy, p-Anisidine and polar compound were analyzed as well. The POV with 30 meq/kg was used as the rancidity index. Furthermore, the shelf-life evaluation of edible oil was based on the time conversion in combination with the American Oil Chemists' Society (AOCS) method as the optimum condition for the HTOV. The results showed that the shelf-life of soybean oil was 266.7 days according to the temperatures used. Moreover, by using AOCS method, the shelf-life of soybean oil was 255.67 days. The best temperature (90℃) and the oxygen ventilation (1.5 ml/min) were applied to measure the oil stability. It showed that the soybean oil showed the worse stability, whereas the sesame oil showed the best stability. This method was also used to analyze the chicken oil added with different ratio of vegetable oil as an innovative oil product. The chicken oil which was heated at high temperature for 8 hours and POV value at 35.51 meq/ kg was used as the control group. The treatment in this experiment was the addition of different kinds and proportion of vegetable oil into chicken oil to increase its oxidation stability. The result showed that the higher proportion of vegetable oil addition revealed better oxidation stability with 50% chicken oil + 45% canola oil + 5% sesame oil was the best treatment. The HTOV method was not only quick and better method to assess quality, stability and shelf-life of edible oils, but also it was used in the oil products development and application.