The inclusion of fresh or processed fruit in yoghurt is a popular method of increasing the phenolic content of the product and improving its antioxidant capacity. This study shows that goji berries can be an alternative method of enriching dairy products with biologically active substances. Enriched dairy products with goji berries have a higher amount of polyphenol compounds and a higher antioxidant capacity compared to the control sample. Enriching dairy products (yoghurt) with natural antioxidants does not cause significant changes in the active acidity (pH) of yoghurt and its nutritional value. Enriched yoghurts with dried berries have a higher phenolic content and a higher antioxidant activity (63.30 ± 1.42 %) than the control (10.57 ± 0.13 %). The high antioxidant activity is due to the radical-absorbing effect of the bioactive compounds found in the enriched yoghurt. Hence, berry berries can be used to enrich dairy products (yoghurt) with biologically active substances and to improve their antioxidant properties. For the food industry, these conclusions may have an important role for yoghurt producers to develop an effective strategy for production of milk with high antioxidant capacity.
