Fermentation of cassava is an important processing technique followed in different parts of the world. Although fermentation is known to bring about vast changes in the physicochemical and functional properties of the tubers, attempts have seldom been made to consolidate and critically analyze the available information. Glaring inconsistencies and contradictions noticeable in some of the results reflect the differences and variations in the artisanal processes followed in the preparation of these products. It also stresses the need for a systematic study of not only the quoted products, but also a number of other fermented cassava products that have not been well documented.
Abstract:The functional properties of the starchy flour extracted from six varieties of cassava subjected to fermentation by a mixed culture inoculum comprised of lactobacilli, streptococci, corynebacteria and yeast cells are examined. Apparent reduction in total and soluble amylose contents is observed. Differential scanning calorimetry of the samples indicated that the enthalpy of gelatinisation was reduced, while the gelatinisation temperature was enhanced. A marked reduction in Brabender viscosity values of starch from fermented tuber was observed, but the X-ray diffraction pattern was unaffected. All these changes were attributed to the presence of fibrous material and consequent reduction of starch in unit volume rather than any change in the starch granule structure.
The biochemical changes brought about in cassava tubers during fermentation (72 h) with a mixed culture inoculum are delineated. The initial starch content of the four cultivars studied ranged from 216 to 331.3 g kg-* and only
Abstract:The efficacy of a mixed culture inoculum in detoxifying intact cassava tuber and peel pieces was investigated. Fermented cassava tuber and peel pieces had more linamarase activity than the non-fermented control samples and this might have resulted partly from the release of endogenous linamarase from the retted tuber/peel pieces and partly due to the microbial linamarase. Approximately 24-26 % of the total cyanide remained in the bound form in the fermented tuber while 67-79% existed as bound cyanide in the non-fermented controls. In cassava peels, only 15-33% of total cyanide remained in bound form after 72 h fermentation while 58-59% cyanide existed in bound form in the parallel nonfermented control peels. Free cyanide which could be easily eliminated through sun-drying was present a t higher concentrations in the fermented tuber and peel compared with the non-fermented samples. The study showed that cassava tuber and peel could be extensively detoxified through fermentation with a mixed culture inoculum.
The efficiency of starch extraction from sweet potato tubers was improved by lactic acid fermentation using a mixed culture inoculum. Study of the properties of the starchy flour showed that there was a significant reduction in the starch content and consequently the soluble and apparent amylose contents of fermented samples from all six varieties used. A fall in peak viscosity and viscosity breakdown was observed for fermented samples, while the pasting temperature was enhanced significantly. The fermented flour showed greater solubility and reduced swelling. Differential scanning calorimetry studies indicated a delay in gelatinisation and a fall in enthalpy of gelatinisation of the starch on fermentation. Unlike cassava, all the properties of the starch from sweet potato tubers, ie viscosity, swelling, solubility, gelatinisation temperature, amylose content and starch content, were affected by fermentation, and variation was also observed among cultivars.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.