Department of Food Science and Nutrition, University of Thessaly, Terma N. Temponera Street, 43100 Karditsa, Greece.
Int J Mol Sci. 2023 Jan 6;24(2):1113. doi: 10.3390/ijms24021113.
Tocopherols are natural bioactive compounds with several health benefits. This study evaluated the effect of different ratios of α- and δ- tocopherol homologs to protect sunflower oil (SO) and olive pomace oil (OPO) against oxidation. A synergistic effect was recorded when the two tocopherols were combined at a ratio of 7:1 (α-T/δ-T). The oil samples were exposed to accelerated oxidation conditions using a Rancimat (90 °C and airflow of 15 L/h for 24 h) and protection from tocopherols was compared with that from butylated hydroxytoluene (BHT). Assessment of oil stability was examined using well-known parameters such as peroxide value (PV), thiobarbituric acid reactive substances (TBARS), p-anisidine value (p-AV), conjugated dienes (CD) and trienes (CT), and total oxidation (Totox) value, which were all significantly reduced when tocopherols were added at a ratio of 7:1 α-T/δ-T. Primary oxidative compounds measured according to PV were only reduced in SO samples (6.11%). Off-flavor compounds measured via TBARS assay in SO samples were reduced by above 20%, while p-AV was also reduced. CDvalue was correlated with PV in SO samples, while the 7:1 mixture was more effective than BHT for CTvalue. Total oxidation values in SO samples and OPO samples were reduced by 6.02% and 12.62%, respectively. These values in SO samples also provided a remarkable correlation (R2 > 0.95) with incubation time. Moreover, the synergistic effect was not only effective in reducing the oxidation values of oil samples, but also in lowering the degradation rate of tocopherols. Protective effects from tocopherols were mainly observed in SO samples, as OPO samples were more resistant to oxidation processes. This effect was even observed in fatty acid analysis, where the 7:1 mixture provided better results than BHT-spiked samples. Thus, it is suggested that tocopherol mixtures might be used as a natural preservative in the food industry to restrain lipid oxidation processes.
生育酚是具有多种健康益处的天然生物活性化合物。本研究评估了不同比例的α-和δ-生育酚同系物对保护葵花籽油（SO）和橄榄渣油（OPO）免受氧化的影响。当两种生育酚以 7:1（α-T/δ-T）的比例组合时，记录到协同效应。使用 Rancimat（90°C 和 15 L/h 的空气流量 24 小时）使油样暴露于加速氧化条件下，并比较生育酚与丁基羟基甲苯（BHT）的保护作用。使用过氧化值（PV）、硫代巴比妥酸反应物质（TBARS）、对茴香胺值（p-AV）、共轭二烯（CD）和三烯（CT）以及总氧化值（Totox）等知名参数评估油的稳定性，当添加比例为 7:1α-T/δ-T 时，所有这些参数均显著降低。根据 PV 测量的初级氧化化合物仅在 SO 样品中降低（6.11%）。通过 TBARS 测定测量的异味化合物在 SO 样品中降低了 20%以上，而 p-AV 也降低了。SO 样品中 CD 值与 PV 相关，而 7:1 混合物对 CT 值的效果优于 BHT。SO 样品和 OPO 样品的总氧化值分别降低了 6.02%和 12.62%。SO 样品中的这些值也与孵育时间呈显著相关性（R2>0.95）。此外，协同效应不仅有效降低了油样的氧化值，而且降低了生育酚的降解率。在 SO 样品中观察到生育酚的保护作用，而 OPO 样品对氧化过程的抵抗力更强。在脂肪酸分析中甚至观察到了这种效果，其中 7:1 混合物比 BHT 加标样品提供了更好的结果。因此，建议将生育酚混合物用作食品工业中的天然防腐剂，以抑制脂质氧化过程。
