Aduol Kevin O, Onyango Arnold N, Mokua Beatrice N Kiage, Okoth Judith K, Ayua Emmanuel O
Department of Human Nutrition Sciences, School of Food and Nutrition Sciences, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya.
Department of Food Science and Nutrition, University of Eldoret (UoE), Eldoret, Kenya.
J Food Sci. 2025 Sep;90(9):e70555. doi: 10.1111/1750-3841.70555.
Repeated frying with recycled oil promotes lipid peroxidation and fatty acid (FA) profile changes that predispose consumers to increased health risks. The magnitude of such changes differs by oil type, temperature, and extent of recycling. This study aimed to determine changes in FA profiles and nutritional indices of French fries prepared at 150°C and 190°C using palm olein, canola, olive, and sunflower oils recycled up to 10 times, as well as the levels of lipid peroxidation in the oils. FA methyl esters were analyzed by gas chromatography. Nutritional indices were calculated from the FA profiles. Oxidative changes were monitored by peroxide, p-anisidine, and iodine values (IVs). Results showed progressive increases in lipid peroxidation and saturated and trans-fatty acids (TFAs) and decreases in unsaturated FAs, which were worse at 190°C. p-anisidine values (p-AVs) increased significantly at every frying cycle in all the oils, making it a better oxidation indicator than peroxide and IVs. Sunflower and canola oils had the highest, whereas olive oil had the least absolute decreases in unsaturated FAs. Palm olein had the highest increase in TFAs, which is postulated to be indirectly due to its higher content of saturated fatty acids (SFAs). This oil also had higher indices of atherogenicity (IA) and thrombogenicity (IT), and lower hypocholesterolemic:hypercholesterolemic (HH) ratio, which worsened with repeated frying. Thus, during repeated frying at 150°C or 190°C, palm olein, with a less favorable nutritional profile than olive, sunflower, and canola oils, also undergoes higher formation of TFAs.
使用回收油反复煎炸会促进脂质过氧化以及脂肪酸（FA）谱的变化，这会使消费者面临更高的健康风险。此类变化的程度因油的类型、温度和回收程度而异。本研究旨在确定使用回收多达10次的棕榈油精、菜籽油、橄榄油和葵花籽油在150°C和190°C下制备的薯条中FA谱和营养指标的变化，以及油中的脂质过氧化水平。通过气相色谱分析FA甲酯。根据FA谱计算营养指标。通过过氧化物、对茴香胺和碘值（IV）监测氧化变化。结果表明，脂质过氧化、饱和脂肪酸和反式脂肪酸（TFA）逐渐增加，不饱和脂肪酸减少，在190°C时情况更糟。在所有油类的每个煎炸周期中，对茴香胺值（p-AV）均显著增加，使其成为比过氧化物和IV更好的氧化指标。葵花籽油和菜籽油中不饱和脂肪酸的绝对减少量最高，而橄榄油最少。棕榈油精中TFA的增加量最高，据推测这是由于其饱和脂肪酸（SFA）含量较高间接导致的。这种油还具有较高的致动脉粥样硬化指数（IA）和血栓形成指数（IT），以及较低的降胆固醇：升胆固醇（HH）比率，随着反复煎炸情况会恶化。因此，在150°C或190°C下反复煎炸期间，棕榈油精的营养状况不如橄榄油、葵花籽油和菜籽油，其TFA的形成量也更高。
