Evaluating the Physicochemical Properties of Milk Enriched with Sesame Seeds

Abstract

Full-fat dairy products contain large amounts of saturated fatty acids and cholesterol, which can have a harmful impact on human health, especially in patients with cardiovascular diseases. Therefore, considerable efforts have been devoted to reducing the contents of these compounds in nutrients. In the ground sesame seeds, they were added to milk in 10%, 20%, 30%, and 40% proportions. The samples were stored in a refrigerator at 5°C. They were subjected to chemical tests (acid value (AV), peroxide value (PV), fatty acid analysis, and antioxidant compounds) and physical tests (color, syneresis, and apparent viscosity). The results indicated a significant increase in AV and PV (p<0.01) with an increased percentage of ground sesame seeds, which, in turn, led to increased amounts of unsaturated fatty acids and reduced amounts of saturated fatty acids according to the results of fatty acid profile analysis. Examining the total phenolic content of the treatments showed a significant increase (p<0.01) in phenolic compounds in milk on day 7 of storage, with an increase in the percentage of ground sesame seeds. According to the evaluation results of colorimetry components, the milk treatment containing 40% ground sesame seeds (p≥0.01) had the lowest value of lightness index (L*), the highest value of yellowness index (b*), and the lowest value of redness index (a*). Analyzing apparent viscosity on the first day after product manufacture indicated no significant difference (p>0.01) in the viscosity of milk samples with different percentages of ground sesame seeds, while it decreased on days 3 and 7 with an increase in sesame percentage. The results of this research generally indicated the feasibility of producing milk containing ground sesame seeds as a functional food with increased amounts of unsaturated fatty acids and antioxidant compounds as well as suitable physical properties.

Keywords: Functional, Unsaturated Fatty Acids, Phenolic Compounds, Black Sesame, Milk