Santos Carla S P, García Lucía Molina, Cruz Rebeca, Cunha Sara C, Fernandes José O, Casal Susana
1LAVQ/REQUIMTE, Laboratory of Bromatology and Hydrology, Faculty of Pharmacy, University of Porto, Rua Jorge de Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
2Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Campus las Lagunillas, 23071 Jaén, Spain.
J Food Sci Technol. 2019 Jan;56(1):290-301. doi: 10.1007/s13197-018-3489-z. Epub 2018 Nov 29.
Aiming to distinguish the nutritional and safety impacts on consumer's health of prolonged frying with vegetable oils rich in monounsaturated fatty acids (MUFA), namely peanut oil (PO), canola oil (CO) and extra virgin olive oil (EVOO), a domestic deep-frying assay using fresh potatoes was implemented (175 °C, 8 h per day, up to 28 h). Based on a total polar compounds (TPC) degradation limit of 25%, PO and CO enabled 18-20 h of frying, while EVOO allowed significantly higher frying hours (> 28 h). Despite the non-significant variations in oxidized triglycerides contents observed through time, and loss of all major antioxidants during the first 8 to 12 h of frying, PO showed statistically higher amounts of conjugated dienes (27 at 20 h; against 19 in CO and 17 in EVOO) and CO of anisidine value (252 at 20 h; against 209 in PO and 100 in EVOO), indicative of different oxidation patters. This was corroborated with the analysis of major volatiles, with PO and CO being statistically richer in alkenals and alkadienals, respectively. Therefore, despite the MUFA predominance, differences in their unsaturation profile impact on the type and amount of degradations products formed under prolonged frying and consequently on consumer's health. As to EVOO use for prolonged frying, despite its increased resistance to oxidation and lower risk of formation of unhealthy volatiles, it loses its pool of natural bioactive compounds in the first hours of frying.
为了区分富含单不饱和脂肪酸（MUFA）的植物油（即花生油（PO）、菜籽油（CO）和特级初榨橄榄油（EVOO））长时间油炸对消费者健康的营养和安全影响，进行了一项使用新鲜土豆的家庭油炸试验（175°C，每天8小时，最长28小时）。基于总极性化合物（TPC）降解限度为25%，PO和CO可进行18 - 20小时的油炸，而EVOO允许显著更长的油炸时间（>28小时）。尽管随着时间推移观察到氧化甘油三酯含量无显著变化，且在油炸的前8至12小时内所有主要抗氧化剂均损失，但PO的共轭二烯含量在统计学上更高（20小时时为27；而CO为19，EVOO为17），CO的茴香胺值更高（20小时时为252；而PO为209，EVOO为100），这表明氧化模式不同。这在主要挥发性成分的分析中得到了证实，PO和CO分别在烯醛和二烯醛方面在统计学上含量更高。因此，尽管以MUFA为主，但它们不饱和度分布的差异会影响长时间油炸过程中形成的降解产物的类型和数量，进而影响消费者健康。至于将EVOO用于长时间油炸，尽管其抗氧化性增强且形成不健康挥发性物质的风险较低，但在油炸的最初几个小时内它会失去其天然生物活性化合物库。
