Anti-oxidant activity of functional yoghurt incorporated with Hibiscus rosasinensis flower extract

Abstract

Functional herbal yoghurt was developed by incorporating Hibiscus rosa sinensis flower extract at one and two per cent levels. The developed yoghurt was evaluated for physico - chemical parameters, anti-oxidant activity and sensory qualities. Incorporation of hibiscus has significantly increased the anti-oxidant activity. The antioxidant activity of control yoghurt and yoghurt incorporated with one and two per centhibiscus flower extract were 14.4±0.66, 19.78±0.66 and 36.32±0.66per cent respectively. The titratable acidity increased with respect to the increase in concentration of hibiscus extract and period of storage. There was a significant increase in total solids content in yoghurt incorporated with two per cent hibiscus extract. Hibiscus incorporation had also increased the syneresis percentage of yoghurt. Calcium and Iron content of yoghurt increased significantly in hibiscus incorporated yoghurt. Control yoghurt had 88.97±1.56 and 1.14 ±0.01 mg/100 g of calcium and of iron respectively. Yoghurt incorporated with one and two percent hibiscus extract had 124.88±1.67 and 224.8±1.93 mg/100 g of calcium and 1.43 ±0.01 and 1.92 ±0.01mg/100 g of iron respectively. No significant difference was observed in the fat percentage of yoghurt incorporated with hibiscus. Sensory quality of yoghurt was not altered significantly due to the incorporation of hibiscus flower extract. The study revealed that hibiscus flower extract can be incorporated into yoghurt to improve the anti- oxidant property, calcium and iron content of yoghurt without affecting the sensory qualities.