During conventional fermentation of milk into yogurt and kefir, changes of antioxidant capacities (DPPH radical scavenging, ferrous chelating, reducing power, hydrogen peroxide/ H2O2 scavenging activity) and total phenolic content were investigated. Both products showed greater phenolic content, DPPH radical scavenging, and reducing power activities than was the case of their unfermented milk forms. But they were unable to scavenge H2O2. Chelating ability of milk increased by yogurt fermentation but decreased by kefir fermentation. In general, antioxidative capacity of milk improved throughout conventional yogurt and kefir fermentations and ripening periods (except chelating ability for kefir and H2O2 scavenging). This study is valuable since it evaluates the antioxidant power of yogurt and kefir produced by traditional fermentation with 5 different antioxidative approaches. In face of rapidly rising consumer demand for safe, healthy, functional but natural foods, revealed results might strengthen importance of conventional fermentation process and highlight the antioxidative contributions of mentioned products

Fermented milk is known as a major functional food that has proven health benefits, such as probiotic effects. The fermented milk, laban, is the foremost dairy product in Yemen. This study aimed to evaluate the nutritional and health-promoting properties and antioxidant activity of laban. Nutritional and health-promoting properties were estimated. Antioxidant activity was evaluated by measuring total polyphenol levels, 1.1-diphenyl-2-picrylhydrazyl scavenging activity, reducing power, and total antioxidant capacity. The antioxidant activity of a laban-Pulicaria jaubertii mixture was also determined. Results showed considerable quantities of nutrients, especially fats, in both milk and laban. The composition differences between milk and laban show several significant health-promoting properties for laban. Laban showed higher antioxidant activity than raw milk and the addition of P. jaubertii to the laban, increased antioxidant activity. The properties of laban suggested the potential use of laban as a promising functional food with excellent health benefits, especially when mixed with P. jaubertii.