Cyanide detoxification in cassava for food and feed uses
01 Jul 1995-Critical Reviews in Food Science and Nutrition (Taylor & Francis Group)-Vol. 35, Iss: 4, pp 299-339
TL;DR: Fermentation, boiling, and ensiling are efficient techniques for removing cyanide from cassava peels.
Abstract: Cassava (Manihot esculenta Crantz) is an important tropical root crop providing energy to about 500 million people. The presence of the two cyanogenic glycosides, linamarin and lotaustralin, in cassava is a major factor limiting its use as food or feed. Traditional processing techniques practiced in cassava production are known to reduce cyanide in tubers and leaves. Drying is the most ubiquitous processing operation in many tropical countries. Sun drying eliminates more cyanide than oven drying because of the prolonged contact time between linamarase and the glucosides in sun drying. Soaking followed by boiling is better than soaking or boiling alone in removing cyanide. Traditional African food products such as gari and fufu are made by a series of operations such as grating, dewatering, fermenting, and roasting. During the various stages of gari manufacture, 80 to 95% cyanide loss occurs. The best processing method for the use of cassava leaves as human food is pounding the leaves and cooking the mash in water. Fermentation, boiling, and ensiling are efficient techniques for removing cyanide from cassava peels.
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TL;DR: New techniques make it possible to precisely edit plant genomic DNA, providing opportunities to create crop varieties that will help meet the challenges facing agriculture, including an expanding world population and environmental change.
Abstract: Plant agriculture is poised at a technological inflection point. Recent advances in genome engineering make it possible to precisely alter DNA sequences in living cells, providing unprecedented control over a plant's genetic material. Potential future crops derived through genome engineering include those that better withstand pests, that have enhanced nutritional value, and that are able to grow on marginal lands. In many instances, crops with such traits will be created by altering only a few nucleotides among the billions that comprise plant genomes. As such, and with the appropriate regulatory structures in place, crops created through genome engineering might prove to be more acceptable to the public than plants that carry foreign DNA in their genomes. Public perception and the performance of the engineered crop varieties will determine the extent to which this powerful technology contributes towards securing the world's food supply.
365 citations
Cites background from "Cyanide detoxification in cassava f..."
...Cassava produces cyanide, which must be removed before human consumption [38]....
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TL;DR: A simple equation is developed between the total cyanide contents of cassava root parenchyma and the processed product with the % retention of cyanide on processing as discussed by the authors, which is applied to different methods of processing used worldwide.
301 citations
Cites methods from "Cyanide detoxification in cassava f..."
...processing, we note that many different methods have been developed over hundreds of years (Padmaja, 1995)....
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...Focussing attention on the second point of the strategy, viz. processing, we note that many different methods have been developed over hundreds of years (Padmaja, 1995)....
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TL;DR: Several different isolates of S. cerevisiae have been shown to be involved in the fermentations and some of the isolates show pheno- and genotypic characteristics that deviate from those normally recognised for S. Cerevisiae.
Abstract: Indigenous fermented foods and beverages play a major role in the diet of African people. The predominant yeast species seen is Saccharomyces cerevisiae, involved in basically three groups of indigenous fermented products: non-alcoholic starchy foods, alcoholic beverages and fermented milk. These products are to a great extent made by spontaneous fermentation and consequently S. cerevisiae often coexists with other microorganisms even though a microbiological succession usually takes place both between and within species. The functions of S. cerevisiae are mainly related to formation of alcohols and other aroma compounds, but stimulation of e.g. lactic acid bacteria, improvement of nutritional value, probiotic effects, inhibition of undesired microorganisms and production of tissue-degrading enzymes may also be observed. Several different isolates of S. cerevisiae have been shown to be involved in the fermentations and some of the isolates show pheno- and genotypic characteristics that deviate from those normally recognised for S. cerevisiae.
226 citations
TL;DR: In this article, the authors undertake a global tour of urban agriculture throughout the developing world in an attempt to elucidate the various benefits, costs, and hindrances associated with the practice.
Abstract: Urban agriculture is receiving increasing attention throughout the developing world, but debate rages as to whether it is a blessing or a curse. Some see it as savior for the poor, providing food, and livelihoods, yet to others it is responsible for harboring and vectoring pathogenic diseases and is an archaic practice that has no place along the path toward development. Consequently, the activity receives a mixed reception, and despite much support in many instances, it certainly does not enjoy universal unimpeded progress. Here, we undertake a global tour of urban agriculture throughout the developing world in an attempt to elucidate the various benefits, costs, and hindrances associated with the practice. Through this analysis we identify the need for better understanding of the following six aspects if urban agriculture is to make a meaningful contribution to food security and sustenance of livelihoods in the future: (1) the global and regional extent of urban agriculture; (2) the contribution of urban agriculture to communicable diseases, especially malaria but also diarrheal disease; (3) the role that urban agriculture does and/or could play in abating both malnutrition and obesity; (4) the impacts of urban agriculture on women; (5) appropriate methods of achieving governance and institutional support; and (6) the risks posed by chemical pollutants, particularly as Africa becomes increasingly industrialized. Overlaying these, we suggest that the time is ripe to extend the debate about urban agriculture’s positive and negative environmental impacts—especially in relation to carbon emissions—from primarily a developed world concern to the developing world, particularly since it is the developing world where population growth and consequent resource use is increasing most rapidly.
162 citations
Cites background from "Cyanide detoxification in cassava f..."
...Cassava is well-known for its cyanogenic glycoside content (McMahon et al. 1995), but traditional preparation methods such as sun drying, soaking, and boiling remove most of the toxins (Padmaja 1995)....
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...1995), but traditional preparation methods such as sun drying, soaking, and boiling remove most of the toxins (Padmaja 1995)....
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TL;DR: The present findings indicate the suitability of these Lb.
147 citations
References
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TL;DR: An enzymatic assay for the cyanide contents of cassava parenchymal tissue (peeled root, cassava peel or cassava leaves) indicated longitudinal and radial cyanide gradients in the roots, and the problem of sampling bulky roots is discussed.
Abstract: An enzymatic assay for the cyanide contents of cassava parenchymal tissue (peeled root), cassava peel or cassava leaves is described. The material is homogenised in orthophosphoric acid; filtered through glass-fibre paper and aliquots of the filtrate are neutralised and incubated with exogenous linamarase for 15 min. The cyanogenic glucosides present are hydrolysed to free cyanide which is estimated spectrophotometrically. The acid extraction solution inactivates endogenous linamarase, and assay of aliquots without enzyme treatment gives the free (non-glycosidic) cyanide contents of the extracts. The acid extracts are stable for at least 4 days at 4°C, and the steam-distillation/aspiration of earlier methods is unnecessary. The detection limit is < 0.01 mg (0.1 parts 10−6) cyanide per 100 g fresh weight and peeled root, and 40-50 samples per day can be handled easily. Analyses of eight cultivars indicated longitudinal and radial cyanide gradients in the roots, and the problem of sampling bulky roots is discussed.
294 citations
TL;DR: Findings indicate a causal role in konzo of sustained high blood cyanide concentrations maintained by a deficient sulphur intake impairing cyanide to thiocyanate conversion, but a minor improvement of food processing may, as in beri-beri, be preventive.
270 citations