Antioxidant properties and diet-related a-glucosidase and lipase inhibitory activities of yogurt supplemented with safflower petal extract

Recently, the ability to enhance the functions of yogurt using edible plant extracts has been extensively studied. This study was conducted to investigate whether safflower petal, as a natural food additive, can be used to develop functional yogurt with improved health benefits. Safflower petals were extracted with ethanol (SPE) and hot water (SPW), and then safflower yogurt was prepared by adding 0%–1.0% of those extracts to plain yogurt. With an increase in the fermentation duration, the pH of SPE and SPW yogurt samples decreased, whereas titratable acidity and microbial counts increased. The concentration of total polyphenols and total flavonoids, antioxidant activity, and inhibitory effects on reactive oxygen species (ROS) were higher in SPW than in SPE yogurt. Furthermore, the α-glucosidase and lipase activity inhibitory effects of SPW yogurt were higher than those of SPE yogurt. In particular, free radical-scavenging activities, ROS inhibitory effects, and α-glucosidase activity inhibitory effects significantly increased in SPW yogurt in a dose-dependent manner. Overall, these results suggest that safflower petal extract possesses antioxidant activities and can downregulate α-glucosidase and lipase activities. Safflower petal extract may have potential benefits as a natural food additive for the development of functional yogurt.