Characteristics of Anthocyanin pigments extracted from rosella [Hibiscus sabdariffa, L.] and its potential uses as antioxidant and natural food colorants

ABSTRACT

Extraction of anthocyanin from rosella [Hibiscus sabdariffa, L.] was optimized for identification of the major constituents of the extract by HPLC to be used as alternative natural red colorants in some processed foods, i.e. hard candy, as well as to find out its effect as natural antioxidant on corn oil. Rosella anthocyanin contained 620 mg anthocyanin/100g rosella The major constituents were cyaniding 3, 5 diglucoside delphinidin 3 glocoside and cyaniding 3 arabinoside by analyzing with HPLC. The best carrier for rosella anthocyanin was dextrin followed by soluble starch, lactose and glucose, respectively, On the other hand, color and higher pigment stability of anthocyanin extracted from rosella were in acidic conditions at pH value ranging between 1.0 to 3.0 and temperature between 40.0 to 60.0°C. Meanwhile, the degradation of anthocyanin was 58.0% of the total pigments after 180 mm at 100°C. Antioxidant activity of rosella extracts was assessed by measuring the peroxide value in corn oil during 7 days at 60°C, where, corn oil containing 200, 500, 1000 ppm lowered the peroxide value compared using 200 ppm synthetic antioxidant [200 ppm]. Analysis of variance for sensory evaluation of prepared hard candy indicated that, hard candy containing 0.20% rosella anthocyanin pigments had the highest score of color, taste and overall acceptability similar to the synthetic color carmine