Chemical composition of roselle (Hibiscus sabdariffa l.) seeds fermented at varying durations
A study was carried out to determine the chemical composition of roselle seeds fermented at varying durations. One kg cleaned Roselle seeds were soaked in 3L of water for 8 hours. The soaked seeds were drained and fermented for 0, 24, 48, 72 and 96 hours as treatments. Samples of fermented roselle seeds at different duration of fermentations were analyzed for chemical composition including anti-nutritional factors. The results showed that there was significant (P<0.05) effect of fermentation duration on chemical composition and antinutritional factors of roselle seeds. Dry matter and crude protein content increased as fermentation duration increased from 0 to 96 hours. The highest dry matter (91.87%) and crude protein (35.05%) were obtained at 96 hours while crude fibre and ether extract decreased with increased fermentation duration. Crude fibre (6.55%) and ether extract (26.79%) were highest at 0 hours. Ash and nitrogen free extract content ranged from 5.41 – 5.78 % and 30.62 – 39.19 %, respectively. Anti-nutritional factor contents declined with increased fermentation duration. The lowest values for saponin (2.02%), tannin (0.15%), phytic acid (5.44%) and trypsin inhibitor (8.93%) were obtained at 96 hours fermentation. It can be concluded that roselle seeds fermented for 96 hours enhanced nutrient availability and significantly reduced tannin, phytate, saponin and trypsin inhibitor anti-nutritional factors.
Keywords: Anti-nutritional factor, chemical composition and fermentation.