Stability study of water-in-oil emulsion containing anthocyanins from red cabbage

Abstract

One of the main factors in the formulation and control of water-in-oil emulsion is the development of desirable solid-to-liquid ratios, achieved by hydrogenation and blending. Formulation of water-in-oil emulsion with bioactive compound could provide additional value and stability to the emulsion for food application for example in margarine. The objectives of this study were to formulate water-in-oil emulsions i.e. margarine containing bioactive compound (anthocyanins) extracted from red cabbage (Brassica oleracea L.) and to study the storage and stability characteristics of the emulsions. The anthocyanins were extracted using hot water extraction method at 60°C with three replications, and encapsulation of anthocyanins was performed using microwave technique to study the dispersion and stability of anthocyanins in the emulsions. In this study, water-in-oil emulsions were formulated with three different oil-to-aqueous ratios (75:25, 80:20 and 85:15) at 60°C for 15 minutes during blending and at 0°C for 30 minutes during crystallization process. The stability of the formulated emulsion was determined by using Solid Fat Content analysis, thermal and phase stability analysis. Total concentration of anthocyanin extracted from red cabbage was 152.33±2.0 mg/L. After 14 days of storage, the emulsion stability was achieved at oil-to-aqueous ratio of 85:15 and with addition of encapsulated anthocyanins. This formulation produced stable emulsion with high melting completion temperature and low onset crystallization temperature.