Nutrient Composition and Phytochemical Screening of Crushed, Toasted and Fermented Roselle (Hibiscus sabdariffa L) Seeds

Abstract

Aims: To examine the effects of crushing (CRRS), Toasting (TRS) and fermentation (FRS) on the nutrient composition and phytochemical constituents of Roselle seeds (Hibiscus sabdariffa). Study Design: Rosselle (Hibiscus sabdariffa L) seeds were divided into three (3) and subjected to crushing, toasting and fermentation processing methods. Duplicate samples of 100 grams each of the processed Roselle seeds were subjected to proximate analysis, amino acid evaluation, mineral determination and phytochemical screening while data collected were analysed using one-way ANOVA Place and Duration of Study: Livestock Unit of Faculty of Agriculture, Nasarawa State University Keffi, Shabu- Lafia Campus and the Nutrition Laboratory of the university between October 2014 and November 2014. Methodology: Raw Roselle seeds were subjected to three (3) processing methods viz: crushing (T1), toasting (T2) and fermentation (T3).Duplicate samples of each of the processed Roselle seeds were subjected to proximate analysis, amino acid evaluation, mineral determination and phytochemical screening. Results: Crude Protein (CP), Crude Fat (EE), Crude Fibre (CF), Total Ash, Dry matter (DM), Nitrogen Free Extract (NFE), Methionine, Lysine and Tryptophan values showed significant (P=0.05) increase with fermentation. Na, K, Ca and P were significantly (P=0.05) affected by processing. Phytochemicals screening indicates the presence of alkaloids, saponin, and phenols in an appreciable amount in the crushed and fermented while tannin, flavonoids and glycosides are present in moderate amounts; phlobatannin was found to be moderately present only in fermented Roselle seeds. Conclusion: Nutrient improvement and the preservation of most phytochemical constituents of Roselle seeds was best achieved through fermentation process.