Abstract

Effect of boiling on the physicochemical composition of Roselle seeds (Hibiscus sabdariffa) grown in Mali was shown. Proximate analysis indicated that boiled whole Roselle seeds (BWRS) are potential high protein source. Moreover, the results of lipid analysis indicated that the seeds were good source of unsaturated fatty acid (74.33%) with that of linoleic (35.55%), oleic (36.64%), palmitic (19.34%) and stearic acid (4.86%) being the major fatty acid constituents. The most predominant inorganic elements were found to be potassium, followed by magnesium and calcium. Aluminum and phosphorus were relatively low in both BWRS and un-boiled whole Roselle seeds (WRS). Roselle seeds exhibited various molecular weight distributions as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Scanning electron microscopic (SEM) analysis revealed that boiling had little influence on the physical particles size. In addition, Roselle seed powder meals maintained excellent protein, lipid and minerals compositions, following boiling with protein quality of powders prepared from whole and boiled seeds being similar.

Key words: Roselle seeds, boiling, physiochemical analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, fatty acid.

Abbreviation

Abbreviations: WRS, Whole Roselle seeds; BWRS, boiled whole Roselle seeds;DWRS, defatted whole Roselle seeds; DBWRS, defatted boiled whole Roselle seeds; MW, standard molecular weight; Bikalga, food condiment obtained by traditional uncontrolled fermentation of Hibiscus sabdariffa seeds in African countries; Dawadawa botso (Niger), another name for Bikalga; Datou (Mali),another name for Bikalga; Furundu (Sudan), another name for Bikalga; Mbuja (Cameroon), another name for Bikalga; DHL^®, posting company; SEM, scanning electron microscopic; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis.