Some amino acids have strong antioxidant activity in frying oil. This study aimed to obtain further information including antioxidant activity at different concentrations and interactions with rosemary extract, green tea extract, and ascorbic acid. Antioxidant activity of arginine, cysteine, lysine, methionine, and tryptophan was examined by increasing the concentration in soybean oil (SBO) at 180 °C within the concentration range of 0 to 15 mM. These amino acids showed increased activity with increasing concentration without showing prooxidant activity at the given concentration range. Addition of 15 mM methionine did not inhibit the prooxidant activity of α-tocopherol at high concentrations in SBO while it significantly increased the activity at each concentration of α-tocopherol. Methionine showed an additive effect with a commercial rosemary extract while lysine had an antagonistic interaction in SBO at the total concentration of 5.5 mM. Mixtures of green tea extract and methionine did not show better activity than methionine alone in SBO and stripped SBO. (-)-Epigallocatechin gallate, the major active component in green tea, showed a synergistic effect with methionine in stripped SBO but there was no significant interaction effect in SBO. Although ascorbic acid had a synergistic effect with methionine in stripped SBO, it showed a significant antagonistic effect in SBO. Methionine had strong antioxidant activity in six other vegetable oils showing a moderate correlation (R2 = 0.45 to 0.52) with the ratio of unsaturated fatty acids to saturated fatty acids indicating the effectiveness may be related to the fatty acid composition of oil. PRACTICAL APPLICATION: Some amino acid such as methionine and lysine showed stronger antioxidant activity than the leading commercial natural antioxidant, rosemary extract. These amino acids showed great potential as a natural antioxidant in frying. The price of food-grade L-methionine is generally lower than rosemary extract and green tea extract. This paper provides information on the concentration effect and interactions with currently used antioxidants such as tocopherols, rosemary extract, green tea extract, and ascorbic acid.

中文翻译：

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氨基酸在油炸温度下的抗氧化活性及其与迷迭香提取物、绿茶提取物和抗坏血酸相互作用的研究

一些氨基酸在煎炸油中具有很强的抗氧化活性。本研究旨在获得更多信息，包括不同浓度的抗氧化活性以及与迷迭香提取物、绿茶提取物和抗坏血酸的相互作用。精氨酸、半胱氨酸、赖氨酸、蛋氨酸和色氨酸的抗氧化活性通过在 180°C 下在 0 至 15 mM 的浓度范围内增加大豆油 (SBO) 中的浓度来检测。这些氨基酸显示出随着浓度增加而增加的活性，而在给定浓度范围内不显示促氧化活性。添加 15 mM 甲硫氨酸不会抑制 SBO 中高浓度 α-生育酚的促氧化活性，而它显着增加了每个浓度的 α-生育酚的活性。蛋氨酸显示出与商业迷迭香提取物的相加作用，而赖氨酸在总浓度为 5.5 mM 的 SBO 中具有拮抗作用。绿茶提取物和甲硫氨酸的混合物在 SBO 和剥离的 SBO 中没有表现出比单独的甲硫氨酸更好的活性。(-)-表没食子儿茶素没食子酸酯是绿茶中的主要活性成分，与剥离的 SBO 中的蛋氨酸显示出协同作用，但在 SBO 中没有显着的交互作用。虽然抗坏血酸与甲硫氨酸在剥离的SBO中具有协同作用，但在SBO中显示出显着的拮抗作用。甲硫氨酸在其他六种植物油中具有很强的抗氧化活性，显示出中等相关性（R2 = 0.45 到 0. 52) 不饱和脂肪酸与饱和脂肪酸的比例表明其有效性可能与油脂的脂肪酸组成有关。实际应用：一些氨基酸如蛋氨酸和赖氨酸显示出比领先的商业天然抗氧化剂迷迭香提取物更强的抗氧化活性。这些氨基酸显示出作为油炸天然抗氧化剂的巨大潜力。食品级L-蛋氨酸的价格一般低于迷迭香提取物和绿茶提取物。本文提供了有关浓度效应以及与当前使用的抗氧化剂（如生育酚、迷迭香提取物、绿茶提取物和抗坏血酸）相互作用的信息。迷迭香提取物。这些氨基酸显示出作为油炸天然抗氧化剂的巨大潜力。食品级L-蛋氨酸的价格一般低于迷迭香提取物和绿茶提取物。本文提供了有关浓度效应以及与当前使用的抗氧化剂（如生育酚、迷迭香提取物、绿茶提取物和抗坏血酸）相互作用的信息。迷迭香提取物。这些氨基酸显示出作为油炸天然抗氧化剂的巨大潜力。食品级L-蛋氨酸的价格一般低于迷迭香提取物和绿茶提取物。本文提供了有关浓度效应以及与当前使用的抗氧化剂（如生育酚、迷迭香提取物、绿茶提取物和抗坏血酸）相互作用的信息。