Effect of processing on the proximate composition of sunflower (Helianthus annuus) seeds
Over-exploitation of conventional protein-rich plant resources such as soybean and groundnut for human and livestock consumption has necessitated a search for other suitable and under-utilized alternatives such as sunflower (Helianthus annuus) seeds. This study was undertaken to investigate the effect of processing on the proximate composition of sunflower seeds. The processing methods employed were boiling, roasting, solvent extraction and mechanical extraction. There was a substantial recovery of crude protein after processing from 27.02% (in the raw undehulled sunflower seed sample) to values ranging from 32.21% to 45.31% in the dehulled and differently processed samples. Crude lipid ranged from 6.45 to 21.60%, nitrogenfree extract from 11.32 to 19.52%, moisture content from 6.44to 10.29%, crude fibre from 14.19 to 26.35% and ash content from 4.61 to 5.46%. Values of the above proximate parameters were observed to be statistically different (p < 0.05) between the raw and differently processed sunflower seed samples. The results showed that the processing methods employed had improved the nutritional value of sunflower seed. Therefore, in view of its considerably high crude protein content, the study recommends sunflower seed meal as a viable alternative to expensive and over-utilized soybean meal and groundnut cake in feed formulation for fish and livestock.
Keywords: sunflower seeds, processing methods, chemical composition, nutritional potential