Fatty Acid Profile, Conjugated Linoleic Acid Content, and Lipid Quality Indices in Selected Yogurts Available on the Polish Market

Simple Summary Yogurts constitute the most popular fermented milk product. They are usually produced from cow's milk through lactic acid fermentation using Streptococcus salivarius subs. thermophilus and Lactobacillus delbruecki subs. bulgaricus. Yoghurt's nutrient composition is based on the composition of the milk used for its production. There are many factors, including genetic and individual mammalian differences, feed, stage of lactation, age, and environmental factors such as season of the year, that have an impact on the final product composition and quality. Not only milk processing (temperature, exposure to light, time of heating, or storage conditions), but also the process of lactic acid fermentation and the resultant changes in milk constituents can have an effect on the nutritional value of the yoghurt. Various additives added to the yogurt can significantly improve the sensory and health related properties of milk fermented products. Finally, yogurt nutritional composition and quality is subject to changes due to the source and type of milk solids added before fermentation, species and strains of bacteria used in the process, as well as other factors, such as fermentation time and temperature. The fatty acid profile of milk and dairy products is an important factor affecting their nutritional value. The aim of this study was to determine the fatty acid composition, the content of cis9trans11 C18:2 (CLA), and lipid quality indices in yogurts available to consumers in retail sale. The aim of the present study was to determine the fatty acid composition, the content of cis9trans11 C18:2 acid (CLA), and lipid quality indices in yogurts made of cow's milk, available on the Polish market. The test material consisted of: natural yogurts, natural yogurts with additives (muesli, cereal grains), bio yogurts, bio yogurts with additives (millet groats, quinoa, chestnuts), probiotic yogurts, and eco yogurts. All the products were bought in the period from May to June 2021. The conducted research showed that the analyzed yoghurts were characterized by a varying content of fatty acid groups, different values of the calculated lipid quality indices, as well as a different content of conjugated linoleic acid cis9trans11 C18: 2 (CLA). Natural yogurts with additives had the highest content of polyunsaturated fatty acids (PUFAs) and n-3 PUFAs. Natural and bio yogurts with additives had a higher content of n-6 PUF than the other analyzed yogurts. The n-6/n-3 ratio was lower in bio yogurts and eco yogurts. Natural yogurts with additives featured the lowest index of atherogenicity (AI) and index of thrombogenicity (TI) and the highest hypocholesterolemic/hypercholesterolemic ratio (H/H). The fat extracted from the bio yogurts had the highest (0.90% of total fatty acids) mean content of cis9trans11 C18:2 (CLA). In fat of the other analyzed yogurts, mean CLA content in total content of fatty acids varied from 0.48% in natural yogurts with additives to 0.81% in bio yogurts with additives.

Automated summary

Yogurts are popular fermented milk products, and their nutrient composition and quality can be affected by various factors. This study aimed to examine the fatty acid composition, content of cis9trans11 C18:2 acid (CLA), and lipid quality indices in yogurts available on the Polish market. The results showed that different types of yogurts had varying fatty acid content and lipid quality indices, as well as different levels of CLA. Natural yogurts with additives had the highest content of polyunsaturated fatty acids and n-3 PUFAs, while bio yogurts had a lower n-6/n-3 ratio. The fat extracted from bio yogurts had the highest mean content of CLA.