Physicochemical and antioxidant properties of Greek yoghurt fortified with carrots

Abstract

This study investigates the impact of carrots on the physicochemical and antioxidant properties of Greek yoghurt in 24-hour, 7-, 14- and 21-day storage periods. Greek yoghurt was produced by reconstituting 1500 g of powdered milk with 5 litres of water, homogenised, pasteurised at 45°C for 3 minutes, and cooled. 15000 g of sugar and blanched carrots were added at varying levels: 0 g (T1) control, 100 g (T2), 200 g (T3), 300 g (T4), and 400 g (T5). The mixture was incubated at 43°C for 14 hours, strained, packaged, and refrigerated at 4°C for 21 days. A completely randomised 5×4 factorial design was adopted. Results showed significant effects (p<0.05) of storage and carrot inclusion on all parameters. Water holding capacity ranged from 61.38 ± 0.03 to 68.06 ± 0.06% and viscosity from 521.03 ± 0.01 to 544.67 ± 0.02 Pa.s. The pH values increased with storage from 4.40 ± 0.00 to 5.11 ± 0.00 and decreased with carrot inclusion, from 5.23 ± 0.01 to 4.67 ± 0.00. Moisture content increased with storage from 53.84 ± 0.02 to 62.60 ± 0.03%, while fat (7.69 ± 0.01 to 6.50 ± 0.00%), protein (12.75 ± 0.01 to 9.72 ± 0.01%) and carbohydrate (23.74 ± 0.03 to 19.72 ± 0.03%) contents decreased over time. Antioxidant activity (DPPH) decreased over time, with T3 having the highest (43.41 ± 0.03%) and T5 having the lowest (34.43 ± 0.01%) values. In conclusion, adding 200 g/L of Greek yoghurt provides the best functional Greek yoghurt product.