Laboratory of Food Function Analysis, Graduate School of Agricultural Science, Tohoku University, Japan.
Department of Molecular Pathobiology, Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka 812-8582, Japan.
Food Res Int. 2024 Feb;178:113913. doi: 10.1016/j.foodres.2023.113913. Epub 2023 Dec 22.
Milk is a rich source of essential nutrients such as lipids. However, lipid oxidation can be considered a crucial factor in determining the initial stage of milk deterioration. Therefore, it is essential to identify the mechanisms of lipid oxidation, such as photo-oxidation or thermal oxidation, to efficiently prevent it by selecting proper antioxidants. In this study, the oxidation mechanisms of long-life (LL) milk were investigated, and triacylglycerol hydroperoxide isomers generated corresponding to the oxidation mechanisms were analyzed by LC-MS/MS. This study first prepared the standard of TG 4:0_16:0_18:1;OOH isomers, which are the appropriate target for evaluating LL milk's oxidation mechanism. The authentic standards provided the robust analysis of TG 4:0_16:0_18:1;OOH isomers and suggested that LL milk was susceptible to photo-oxidation rather than thermal-oxidation. Furthermore, it was discovered that radicals play a role in the oxidation of LL milk during photo-oxidation. This information could be valuable in effectively preventing photo-oxidation in LL milk. It is important to note that milk is contained in a variety of food products. Hence, these findings would be applicable not only to milk but also to various milk-containing food products.
牛奶是脂质等必需营养素的丰富来源。然而，脂质氧化被认为是决定牛奶变质初始阶段的关键因素。因此，通过选择合适的抗氧化剂，确定脂质氧化（如光氧化或热氧化）的机制，有效地防止脂质氧化至关重要。本研究调查了长保质期（LL）牛奶的氧化机制，并通过 LC-MS/MS 分析了与氧化机制相对应生成的三酰基甘油过氧化物异构体。本研究首次制备了 TG 4:0_16:0_18:1;OOH 异构体的标准品，这是评估 LL 牛奶氧化机制的合适目标。真实标准品为 TG 4:0_16:0_18:1;OOH 异构体的有力分析提供了依据，并表明 LL 牛奶易受光氧化而不是热氧化的影响。此外，还发现自由基在光氧化过程中在 LL 牛奶的氧化中起作用。这些信息对于有效防止 LL 牛奶的光氧化非常有用。需要注意的是，牛奶存在于各种食品中。因此，这些发现不仅适用于牛奶，也适用于各种含牛奶的食品。
