Abstract

• Roselle calyces have the intense red colour due to the accumulation of anthocyanins. They could be extracted using distilled water and 2 % citric acid solution. Total anthocyanins content expressed as cyanidin – 3- glycoside in each extract was determined by pH differential method. Total anthocyanins content of 2 % citric acid extract was higher than that of watery extract. Some quantitative tests for anthocyanins extract were carried out by using ferric chloride, dilute hydrochloric acid and dilute sulphuric acid. Powders of anthocyanins were prepared using different wall materials : maltodextrin (MD), gum arabic (GA) and a combination of maltodextrin and gum arabic (MD + GA) with 1 : 1 ratio. Tween – 80 was used as emulsifier. Each of the wall materials was homogenized to the core material with the ratio of 1 : 1 and were micro encapsulated by microwave –assisted drying at 1100 W. The encapsulated powders were analysed for moisture, hygroscopicity, colour density and morphology. The stability of anthocyanins powder was evaluated under different temperature conditions (Refrigerator, room temperature, sunlight). The results indicated that encapsulated powder with the GA and MD combination gave the better quality of powder and it could be applied in colouring of jelly.