Sterols, tocopherols, and bioactive fatty acids differences between conventional, high quality, and organic cow milk

Milk contains several components that are important for human nutrition and health. To date, studies on organic and conventional milk have focused on their gross composition and fatty acid content, but little attention has been paid to the differences between other minor components such as sterols and vitamins which may have functional actions. The aim of this study was to investigate the nutritional differences between three types of milk from a dairy plant: conventional, high quality (D.M. 185/1991), and organic (in compliance with European Regulations), focusing on minor components such as sterols of animal and plant origin (phytosterols), tocopherols, and bioactive fatty acids. Cholesterol ranged from 271.37 mg/100g of fat in conventional milk to 278.76 mg/100g of fat in organic milk. Lanosterol was the main minor animal sterol in cow's milk (ranging from 3.41 to 4.37 mg/100g of fat), followed by desmosterol. The amount of total plant sterols in the analyzed milk ranged from 4.43 mg/100 g of fat in organic to 4.71 mg/100g of fat in high quality milk. Brassicasterol was the main sterol of plant origin which varied from 2.6 mg/100 g of fat in conventional and organic milk, to 2.93 mg/100g of fat in high quality milk. The second most present phytosterol was beta-sitosterol, which ranged from 0.86 mg/100 g of fat in conventional to 0.97 mg/ 100 g of fat in high quality and organic milk. The results of the study showed that there were no significant differences in gross, and sterol composition between the three types of milk. However, the only significant difference found was in the fatty acid profile, with a higher omega-3 content found in high-quality milk than in conventional and organic milk. These findings suggest that the investigated product categories and labels have minimal effect on the sterol and fatty acid profile of commercial cow's milk.