In the master's thesis, we investigated the oxidative stability of fatty acids in infant formulas after opening the packaging. In the master's thesis, we investigated the oxidative stability of fatty acids in infant formulas. The formulas were exposed to various storage conditions, and the fatty acid composition was monitored throughout the intended shelf life. Additionally, we measured color parameters (L*, a*, b*), calculated the color difference (ΔE), and determined the thiobarbituric acid (TBA) value. We established four experimental groups: Group 1 - samples analyzed immediately after opening the packaging (control). Group 2 - samples stored in closed 50 mL centrifuge tubes in a water bath at 50 °C until the end of the shelf life. Group 3 - samples stored in open 50 mL centrifuge tubes at room temperature until the end of the shelf life. Group 4 - samples stored in closed 50 mL centrifuge tubes at room temperature until the end of the shelf life. The results of the fatty acid composition indicated good stability of the infant formulas. Among monounsaturated fatty acids (MUFA), significant changes were observed in vaccenic acid, whereas among polyunsaturated fatty acids (PUFA), DHA, GLA, and DPA were the most sensitive, showing a significant decrease under certain storage conditions. In contrast, EPA demonstrated high stability, as its levels remained unchanged under different storage conditions. The lowest values of L* and a*, and the highest value of b*, were recorded in Group 2, which was exposed to elevated temperature. Similar findings were observed for ΔE and TBA values, which were also the highest in Group 2, confirming the negative effect of high temperatures on the oxidation process.
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