Study of the Physicochemical and Functional Properties of Gum Extracted from Roselle Petals

Abstract

The study aimed to extract gum from Hibiscus sabdariffa petals and investigate its physicochemical and functional properties. The extracted gum is classified as a natural gum composed of polysaccharides. The chemical composition analysis revealed that Hibiscus sabdariffa gum contained 6.76% moisture, 3.95% protein, 0.7% fat, 10.5% ash, and 78.2% carbohydrates. The extraction yield of Hibiscus sabdariffa gum using aqueous extraction at pH 7, a temperature of 25°C, a plant-to-water ratio of 10:1 (w/v), and a soaking time of 15 minutes was 10%. The gum was precipitated using ethanol at a gum-to-ethanol ratio of 2:1 (w/w) based on the obtained gum yield. The results of the functional properties assessment demonstrated that the extracted gum exhibited good functional characteristics, including a viscosity of 259.5 cP, water-binding capacity of 4.76 g/g, and fat-binding capacity of 15.67 g/g gum powder. The minimum gelation concentration was 3%, and the gum showed an emulsifying capacity of 74.39%. The foam capacity was 81% at the highest concentration (0.7%), and foam stability increased with gum concentration, reaching a maximum stability of 137% at 0.7% gum concentration.