Pathways for Reducing Anti-Nutritional Factors: Prospects for Vigna unguiculata

Abstract

Cereals, pulses and legumes are the most consumed foods in Sub-Saharan Africa. Cowpea, Vigna unguiculata (L.) walp is one known of these legumes as a good source of proteins, some minerals, and fibers. However, the presence of anti-nutritional factors (ANFs) including phytates, alpha-galactosides such as raffinose and stachyose, and tannins reduce significantly the micronutrients and also create some problems of acceptability in using cowpea and other legumes. This review article rep the current knowledges on key aspects of technologies used to reduce ANFs. Some of them proposed one either pathway or combining many techniques such as soaking, sprouting, fermentation, extrusion cooking and steam pre-cooking in order to reduce these ANFs. In fact, steam pre-cooking seems to be the most promising among established processes because of its potential to reduce ANFs up to 96%. Nevertheless, soaking can reduce ANFs up to 45% with higher reductions by adding sodium bicarbonate. Sprouting however can record more significant reductions of 33 to 72% of tannins, 96% of phytates, 92% of stachyose and 67% of raffinose. With regard to fermentation, a reduction rate in ANFs exceeding 50% was found. The extrusion technic reduces up to 55.83% at 140 ° C and 20% humidity while the steam pre-cooking resulted reductions of up to 52.60% at 110 ° C for 25 minutes. In this regard, it is critical to investigate mechanisms that would improve these reductions and furthermore, investigate all strategies used to increase bioavailability of nutrients under specific technological condition.