Effect of processing methods on nutrient retention and contribution of cassava (manihot spp) to nutrient intake of Nigerian consumers

摘要

There is a global drive for promotion of indigenous foods and feedstuffs as a means of dietary diversification in meeting dietary needs of the people living the traditional lifestyle. Cassava diets constitute a staple source of energy for most Nigerians. However, there is little or no documentation on the nutrient composition, effect of processing methods on nutrient retention and contribution of these diets to nutrient intake of consumers. Nutrition information on contribution of a particular food or diet to nutrient intake of consumers is of paramount importance in food labeling and consumer acceptability. This study, therefore, aimed at providing information on nutrient composition and effect of processing methods on nutrient retention and contribution of some diets prepared from cassava. Fresh cassava roots were obtained from a farm in Alegongo area, Akobo, Ibadan, Oyo State, Nigeria. Proximate and mineral composition of prepared samples was determined alongside the market samples using standard methods of Association of Official Analytical Chemists (AOAC) and atomic absorption spectrophotometry, respectively. The crude protein, lipid, fibre and ash contents of fresh cassava roots were low (0.9, 0.3, 0.5 and 0.4g/100g, respectively). Its mineral profile was: potassium 166.6, sodium 222.1, calcium 25.0, magnesium12.5, phosphorus 57.3, iron 1.7, and zinc 2.1 mg/100g sample. Processing cassava roots into various products improved availability of nutrients such as protein (1.3g in gari to 2.6g in fufu and amala), ash (0.5g in abacha to 2.6g in eba), potassium (234.5mg in three days fermented garri to 473.2mg in two days fermented lafun), calcium (22.7mg in eba to 67.3mg in two days fermented lafun), iron (1.0 – 4.3mg), zinc (2.5 – 6.7mg), as well as their calories (p<0.05). A 100g portion of raw and processed cassava into amala, eba, fufu and abacha yielded 140.5, 289, 284, 312, and 358 kilocalories of energy, respectively. Soaking fresh cassava for more than two days resulted in significant reduction in mineral content of prepared diets due to leaching. 100g portion of various diets can contribute between 12.3 to 16.1% energy, 6 to 14% iron, and up to 28% zinc to % RDAs of consumers.