Physicochemical properties and antioxidant activity of curd yogurt fortified with carrot powder

This study evaluated the physicochemical properties, bioactive compound contents, and antioxidant capacity of yogurt supplemented with 0%, 3%, 6%, and 9% carrot powder, replacing skim milk powder. As fermentation progressed, pH decreased and titratable acidity increased across all groups, while viscosity increased over time, although no significant differences were observed among treatments. Lactic acid bacteria counts rose steadily during 24 h of fermentation, with slightly higher final counts (7.94-7.98 log CFU/mL) in yogurts containing 3-9% carrot powder, which may be associated with carrot powder concentration. Total polyphenol, flavonoid, and carotenoid levels increased with higher carrot powder addition, and antioxidant activity was enhanced in a concentration-dependent manner, with DPPH and ABTS scavenging rising from 36.7% to 54.7% and 33.1% to 46.0%, respectively. Increases in reducing power and bioactive compound levels further support the functional benefits of carrot powder enrichment. These results indicate that incorporating carrot powder can modestly improve the nutritional and functional quality of yogurt, highlighting its potential as a natural additive in dairy product development.