Extended Storage of Yoghurt by Using Water Extract of Coriander Seeds

Abstract

The objective of this study was to evaluate the effects of coriander seed extract on the chemical and sensory properties of yoghurt during storage. Coriander seed extract was incorporated in yoghurt at different concentrations, 18 mg/ml (T1C1), 36 mg/ml (T2C2), and 54 mg/ml (T3C3), while a sample without extract (T0C0) was used as a control. Samples were stored at 4°C and were assessed every seven days. The values of lactose, fat, pH, protein, tyrosine, acid degree value, acid value, free fatty acid, and sensory properties for all samples containing extract give higher scores than those of yoghurt without extract. Chemical and sensory evaluations of the yoghurt without plant extract revealed a significant degradation beyond days 28 of storage due to high acidity, and an unpleasant flavour. By contrast, the concentrations of 18, 36 and 54 mg/ml, were shown to have remarkable preservation activity in yoghurt at 42 days. The formulation T3C3, fortified with coriander seed extract at 54 mg/ml, had the highest value in preserving the chemical properties of yoghurt after 42 days, compared with formulas T1C1 and T2C2, which contained 18 mg/ml and 36 mg/ml respectively. Results suggest that coriander extract can be added to dairy products as a natural food preservative, to improve stability during storage.