Foaming Characteristics of Saponins of Leaves of Hibiscus Sabdariffa Linn (Red Variety)

Abstract

 The aim of this study was to determine the foaming characteristics (foam power and foam stability) of saponins of the leaves of Hibiscus sabdariffa Linn. The preliminary screening for saponins and phytochemical screening were carried out to determine the probable presence of saponins and other secondary metabolites. The results showed the probable presence of saponins in the leaves of Hibiscus sabdariffa Linn. Cold maceration extraction method was conducted and yields were obtained from the extracts i.e. aqueous, methanol, and n-butanol. The methanol extract possessed the highest yield of 46.53 % compared to aqueous and n-butanol extracts with 8.15 % and 0.69 % respectively. The foam heights and foaming times of aqueous, methanol and n-butanol extract and that of synthetic detergents (Tween 80 and Triton X-100) when subjected to statistical analysis (ANOVA) showed significant decreases (at p<0.05) between the foam heights (H_0, H_1, and H₅) and foaming times (Tc) at varying concentrations. The foam power of n-butanol extract at 0.5 % was the highest with values of 40.47 % indicating that it was not stable when compared with the values of 87.28 % and 73.57 % for Triton X-100 and Tween 80 respectively. Therefore, saponins of the leaves of Hibiscus sabdariffa Linn. may be of limited use in the detergent industries but relevant in related industries. It is recommended that the foaming properties of the crude saponins would be more enhanced when subjected to further purification processes to meet the standards of Triton X-100 and Tween 80.