Studies on the microbiology of cassava retting for foo‐foo production

Abstract

Okafor N. Ijioma B. Oyolu, C. 1984. Studies on the microbiology of cassava retting for foo‐foo production. Journal of Applied Bacteriology56, 1–13. Five bacteria (Bacillus, Lactobacillus, Klebsiella, Leuconostoc, and Corynebacterium) and a yeast (Candida spp.) were isolated from cassava being fermented for foo‐foo production. Retting of cassava was assessed by determining the weight required to crush cylindrical cassava pieces. A weight in excess of 2.5 kg was required to crush an unfermented peeled cassava cylinder 4 mm diameter and 4 cm long whereas a weight as small as 20 g could crush the same piece after retting. The organisms were studied for their ability to cause retting of sterile cassava pieces, alone or in various combinations. Retting did not occur unless either the Bacillus sp. or the Corynebacterium sp. was present. Only these two organisms hydrolysed starch. The lactic acid bacteria lowered the pH of the fermenting medium although they did not bring about retting. The typical aroma of foo‐foo was produced, however, only when the lactic acid bacteria were present in the mixture. Only the Corynebacterium sp., was, however, shown to produce pectinolytic enzymes and it is possible that the Bacillus sp. caused retting by disintegrating other cell components. The typical aroma of foo‐foo is disliked by some individuals and it seems possible that foo‐foo with a bland aroma, which will presumably be more acceptable to this group, can be produced by using organisms causing retting while excluding those forming lactic acid.

Nigerian Indigenous Fermented Foods: Processes and Prospects

“…Cassava tubers are rich in starch [20-30%] and with possible exception of sugar cane; cassava is considered the highest producer of carbohydrates among crop plants. Despite its vast potentials, the presence of the two gynogenic glycosides, lineman calculating for 93% of total content (Okafor et al, 1984) and lotaustralin or methyl linamarin, hydrolysis by the enzymes linamarase to release toxic HCN, is the most important problem limiting cassava utilization. Generally cassava contains 10-500 mg HCN/KG of root depending on the variety, although much higher levels, exceeding 1000 mg HCN/kg, may be present in unusual cases.…”

“…Fermentation is by far the most common method of processing the cassava crop in Africa (Okafor et al, 1984). The rate of detoxification of cyanide by traditional fermentation is shown in figure 13.…”

Towards the development of a common starter culture for fufu and usi (edible starch): Screening for potential starters

“…Fufu was described by Sanni et al (1998) as a fermented wet-paste from cassava and it is ranked next to gari as an indigenous food of most Nigerians. It is widely consumed almost across the country, with different preparation methods and ethnic names (Okafor, Ijioma, & Oyolu, 1984;Oyewole & Odunfa, 1989;Longe, 1980;Ayankunbi, Keshinro, & Egele, 1991). Traditionally, peeled and washed cassava roots are manually cut into chunks of different sizes and soaked in earthen pots or drums of water for 3 to 5 days to undergo lactic acid fermentation.…”

“…The fine, clean starch is then dewatered by putting in raffia or cotton bags, then, pressed with heavy stones overnight (Oyewole & Odunfa, 1989). Fermentation still remains the best and widely used means of processing cassava into different products (Oyewole, 1992;Nweke, Dunstan, Spencer, & Lyman, 2002) but chance inoculation (Oyewole & Sanni, 1995), little or no control over the process (Oyewole, 1997), roots cut size (Okafor et al, 1984), difference in dry matter content (Hahn, 1989) and invasion by undesireable organisms characterizes the spontaneous process, thus, resulting in longer fermentation times as well as inconsistent final products (Kimaryo, Massawe, Olasupo, & Holzapfel, 2000). The controlled fermentation of some cassava products has been attributed to the use of microbial starter culture which is a preparation containing large number of viable microorganisms, mostly lactic acid bacteria (LAB) which often resulted in products of consistent properties (Holzapfel, 1997;Holzapfel, 2002).…”

Efeito da fermentação na qualidade de "chips" de mandioca (Manihot esculenta Crantz)

“…OKAFOR, IJIOMA & OYOLU [21] verificaram que, para o mesmo tipo de fermentação submersa, somente os microrganismos dos gêneros Corynebacterium sp. e Bacillus sp.…”