tailieunhanh - Fermentation of cassava

The fermentation of cassava which normally takes 3-4 days during village processing can be shortened to 24h by seeding a fresh pulp with cassava juice 4 days old. In the work described here, a further attempt has been made to elucidate the nature of biochemical reactions taking place during fermentation, and to establish the optimum conditions which could be utilised in a modern industry based on this process. | FERMENTATION OF CASSAVA By I. A. AKINRELE Cassava Manihot utiỉissima Pohl is usually fermented during preparation when it becomes detoxified and develops a characteristic flavour. This fermentation was found to be self-sterilising exothermic and anaerobic and to proceed in two stages at an optimum temperature of about 35 . Lactic and formic acids are produced with a trace of gallic acid. The process could be made continuous. Introduction The fermentation of cassava Manihot utilissimà is a very important step during the preparation of gari a popular food among the low income group in the southern regions of Nigeria which is also eaten extensively along the coast of West Africa. Its significance has already been reported1 that it brings about the detoxification of cassava by the liberation of hydrocyanic acid at low pH through the combined activities of Corynebacterium manihot and Geotricum Candida and the development of the characteristic flavour of gari. This fermentation which normally takes 3-4 days during village processing can be shortened to 24 h. by seeding a fresh pulp with cassava juice 4 days old. In the work described here a further attempt has been made to elucidate the nature of biochemical reactions taking place during fermentation and to establish the optimum conditions which could be utilised in a modern industry based on this process. Experimental 1 Effects of temperature on fermentation Weighed quantities of grated cassava pulp were put into labelled vacuum flasks and the progress of fermentation followed by the measurement of the temperature with mercury thermometers. Also samples of about 5 lb. of the grated pulp were placed in beakers half of which were seeded by treatment with I pint of 3-days-old cassava juice added to I cwt. of mash. The beakers in pairs each consisting of seeded and untreated mash were covered and incubated at room temperature about 26 35 40 45 and 500 respectively in thermostats and the progress of fermentation followed by