Traditional retting of cassava roots in the ponds or the rivers

Abstract

The traditional retting of cassava roots occurs in ponds or in backwaters. The medium pH is slightly acidic (pH 5.54) and the pressure of dissolved oxygen is very low (pO2 1.96). The fermentation of cassava roots lasts for three days in the rainy season (October to April) with an average temperature of 26 °C, but it is longer, 5-6 days, in the dry season (May to September) with an average temperature of 23 °C. The fermentation with peeled roots is preferred because it favours the rapid softening of cassava roots and it allows to shorten at least one day the fermentation duration. In addition, the peeled roots after retting contain less tannin than the unpeeled roots and allow to obtain the alimentary products, fufu and kwanga which have a higher whiteness. The bitter variety of cassava roots is more used in fermentation than the sweet variety. Retted cassava dough is well preserved one to two months in account of anti-microbial compounds produced by lactic acid bacteria. The variability of characteristics of the products obtained from retted cassava roots is the reflection of several factors, including the cassava variety, the environmental conditions and the retting method.