Development of iron fortified cassava mahewu (2015)

In Mozambique 97% of the small scale farmers grow cassava in 43% of the total\ncultivated land. In 2012 cassava production was estimated at 10.05 million tons.\nCassava is the second most important staple food after maize. Consumption of\ncassava is estimated at 85 kg per person per year. In Mozambique the diet is\npoor in micronutrients and the prevalence of under-nutrition is estimated at 38%.\nAnaemia is a serious public health concern, affecting more than 40% of young\nchildren, pregnant and nursing mothers. Cassava mahewu a fermented nonalcoholic\nbeverage prepared using indigenous traditional technology.\nFermentation is known to reduce the toxicity of cyanogenic glycosides in both\nleaves and cassava roots. It also results in higher levels of vitamins, especially\nthe B group, essential amino acids, improves the digestibility of protein and\nincreases the bioavailability of minerals. The aim of the present study was to\ninvestigate whether cassava, in the form of mahewu, can be fortified with iron.\nBitter and sweet cassava roots and soil samples, were collected from small\nscale farmers in four Districts of Mozambique. The four Districts are located in\nintermediate and high production areas of cassava. The concentrations of iron\nand other minerals such as aluminum, calcium, copper, manganese,\nphosphorus, lead and zinc in cassava roots and soil, were determined using an\ninductively coupled-plasma optical emission spectrometer (ICP-OES), after\nmicrowave digestion.\nSweet and bitter varieties of cassava from four Districts in Mozambique were\nfermented in a food laboratory, under controlled conditions (45°C for 24 hours)\nand the optimal stage for iron fortification was determined. Samples were\ncollected at hour 0 and hour 24 for microbial analysis, acid concentration and\ntotal solids determination. Fortification with ferrous sulfate (FeSO4.7H2O) and\nferrous fumarate (C4H2FeO4) were investigated. The total iron content of the\nfortified cassava mahewu was determined using Microwave Digestion\nAccelerated Reaction System (MARS) and ICP-OES, while the bioaccessibility of iron in fortified cassava mahewu was assessed using the in vitro dialysability\nprocedure.\nResults showed that the mineral content of soil from the four districts differed\nsignificantly (p ˂ 0.05). There was also a significant difference (p ˂ 0.05) in the\nmineral concentration of the cassava roots from the four varieties, but no\ndifference between sweet or bitter types. The concentration of minerals was\nfound to be significantly higher in soil, than in roots. This difference was greatest\nfor iron concentration, which was not detectable in the root samples, although\nsoil concentration was up to 24.78 mg/kg. Although the reason for this was not\ndetermined, this lack of iron in the roots supported iron fortification of mahewu.\nA significant difference (p ˂ 0.05) in pH was observed between mahewu fortified\nwith ferrous sulfate (4.5) and ferrous fumarate (4.3), with the latter being similar\nto the control. At the beginning of fermentation the acidity was 0.06% and at the\nend 0.30%. The total solids of fermented mahewu were 9.6%. The\nmicroorganisms responsible for fermentation were predominantly lactic acid\nbacteria (LAB) and yeast. The pH and acidity was different to that reported in the\nfermentation of maize mahewu. The fermenting microorganisms and total solids\nwere similar to previous findings for maize mahewu.\nThe total iron content of mahewu fortified with ferrous sulfate was significantly\nhigher (p ˂ 0.05) than mahewu fortified with ferrous fumarate. Both the amount\nand percentage of bioaccessible iron were higher in mahewu fortified with\nferrous sulfate compared to mahewu fortified with ferrous fumarate. It was found\nthat mahewu made using the bitter variety of cassava and fortified with ferrous\nsulfate provided a more bioaccessible source of iron. The stage of fortification\nwas not found to affect the total iron content nor the iron bioaccessibility.\nIt was concluded that cassava roots do not take up iron, even when soils are\nhigh in this metal. Thus the selection of varieties with better uptake of minerals\nand fertilization of soils is recommended, but may not increase concentration of\nessential minerals sufficiently to maintain health in vulnerable communities\nwhere cassava is the main staple. This was the first study in which fermentation\nof traditional cassava mahewu was carried out under repeatable, controlled conditions. It is recommended that fortification occurs at the end of the\nfermentation when done at household level. However, when flour is being milled\nin larger villages, it could be fortified prior to sale in informal markets. There is\nalso the possibility of large scale commercial applications.\nIt is concluded that bitter varieties of cassava will deliver more bioaccessible iron\nto the consumer. Ferrous sulfate is more suitable as iron fortification source for\ncassava mahewu than ferrous fumarate and also is more stable in mahewu.\nFortification of cassava mahewu could contribute to the iron intake of vulnerable\npopulation.\nIn addition, although fortification at the end of fermentation would probably be\nideal for rural communities, as it could be made available in sugar sprinkled into\nthe traditional product, it was shown that fortification of flour used to make\nmahewu would result in significantly higher availability. It is recommended that\niron fortification of mahewu is implemented both at subsistence and commercial\nlevel. This should form part of a communication strategy at community level by\nthe state, in order to improve public health in vulnerable communities in\nMozambique.