Oxidative and Hydrolytic Spoilage of Fatty Raw Materials in Dairy Products

Antioxidant additives can affect the processes of hydrolysis and oxidation in dairy products during storage. This study featured palm oil, sunflower high-oleic oil, and two milk fat substitutes with different compositions. The samples were stored in an open container at 32 ± 1°C and a relative humidity of 75% for 14 days. The intensity of hydrolysis and oxidation was assessed by their acid number and peroxide number. The palm oil sample with 46.91% saturated palmitic acid and Milk Fat Substitute 1 with 37.61% palmitic and 34.96% oleic acid proved to be the most stable mixes. Milk Fat Substitute 2 was rich in polyunsaturated linoleic acid (29.31%) and demonstrated faster hydrolysis and oxidation rates than the palm oil sample and Milk Fat Substitute 1. Lecithin E322 (0.4%) inhibited hydrolytic and oxidative processes. In Milk Fat Substitute 1 without lecithin, the acid number increased from 0.1 to 2.2 mg KOH/g on storage day 14. In Milk Fat Substitute 1 with lecithin, this indicator stopped growing at 1.4 mg KOH/g. Experiments in reducing the growth rate of the peroxide number gave similar results. In Milk Fat Substitute 1, the peroxide number rose from 1 to 5.7 mmol of active oxygen/kg. In the sample without lecithin, it reached 7 .2 mmol active oxygen/kg. Lecithin proved to be an effective antioxidant-emulating additive to composite fat bases in dairy products. On the one hand, it provided high-quality dispersion of water and fat. On the other hand, it was able to inhibit oxidation and hydrolysis.