Abstract:
In this experiment, 1.50% of berry pomace (red raspberry, blueberry, and black currants) was added to the yoghurt product and stored at 4 ℃ for 21 days. The purpose is to study the changes of composition, quality and antioxidant capacity of yoghurt enriched with three kinds of berry pomace during storage. The results showed that the contents of total dietary fiber in red berries, blueberry and black currants were 45.24%, 50.43% and 55.21%, respectively, and the contents of polyphenol were 18.40 mg/g, 18.70 mg/g, 30.00 mg/g, respectively. The contents of flavonoids were 3.00 mg/g, 2.00 mg/g, and 2.90 mg/g, respectively. The contents of anthocyanins were 14.30 mg/g, 14.10 mg/gand 10.50 mg/g, respectively. The DPPH? scavenging capacity (the concentrations of extracts were 10.00 mg/mL) were 92.20%, 84.10%, 61.00%, respectively. Within 21 days of storage, the enrichment of berry pomace did not change the tendency of yoghurt whey precipitation rate and water holding capacity during storage, titration acidity was higher than 88.78, pH was at 4.17~4.51.The enrichment of berry pomace elevated the concentration of total dietary fiber, and yoghurt's hardness, viscosity, cohesiveness and viscosity index were also higher than control. The antioxidant properties of yoghurt were significantly increased. During the storage period, the DPPH? scavenging capacity, total reducing power, and hydroxyl radical scavenging rate were significantly increased to 3.93, 13.11 and 4.28 times, respectively, compared to the control. The addition of berry pomace could be used in yoghurt as functional ingredients.
