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Cassava Roots (cassava + root)
Selected AbstractsThe retail market for fresh cassava root tubers in the European Union (EU): the case of Copenhagen, Denmark , a chemical food safety issue?JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 2 2010Lotte Kolind-Hansen Abstract BACKGROUND: A number of retail shops in Copenhagen sell fresh cassava roots. Cassava roots contain the toxic cyanogenic glucoside linamarin. A survey was made of the shop characteristics, origin of the roots, buyers, shop owner's knowledge of toxicity levels, and actual toxicity levels. RESULTS: Shops selling fresh cassava were shown mostly to be owned by persons originating in the Middle East or Afghanistan, buyers were found to predominantly be of African origin, and sellers' knowledge concerning the potential toxicity was found to be very restricted. Seventy-six per cent of the roots purchased had a total cyanogenic potentials (CNp) above the 50 mg HCN equivalents kg,1 dry weight (d.w.) proposed as acceptable by an EU working group. Two of 25 roots purchased had CNp higher than 340 mg HCN eq. kg,1 d.w. CONCLUSION: The EU has previously made risk assessments concerning cassava and cyanogenic compounds. In the light of the conclusions drawn, the EU needs to make decisions about how to deal with the regulation and control of fresh cassava roots imported to the European food market. Also cassava root products and cassava leaves should be considered. Copyright © 2009 Society of Chemical Industry [source] Nutritional Value of Cassava for Use as a Staple Food and Recent Advances for ImprovementCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 3 2009Julie A. Montagnac ABSTRACT:, Cassava is a drought-tolerant, staple food crop grown in tropical and subtropical areas where many people are afflicted with undernutrition, making it a potentially valuable food source for developing countries. Cassava roots are a good source of energy while the leaves provide protein, vitamins, and minerals. However, cassava roots and leaves are deficient in sulfur-containing amino acids (methionine and cysteine) and some nutrients are not optimally distributed within the plant. Cassava also contains antinutrients that can have either positive or adverse effects on health depending upon the amount ingested. Although some of these compounds act as antioxidants and anticarcinogens, they can interfere with nutrient absorption and utilization and may have toxic side effects. Efforts to add nutritional value to cassava (biofortification) by increasing the contents of protein, minerals, starch, and ,-carotene are underway. The transfer of a 284 bp synthetic gene coding for a storage protein rich in essential amino acids and the crossbreeding of wild-type cassava varieties with Manihot dichotoma or Manihot oligantha have shown promising results regarding cassava protein content. Enhancing ADP glucose pyrophosphorylase activity in cassava roots or adding amylase to cassava gruels increases cassava energy density. Moreover, carotenoid-rich yellow and orange cassava may be a foodstuff for delivering provitamin A to vitamin A,depleted populations. Researchers are currently investigating the effects of cassava processing techniques on carotenoid stability and isomerization, as well as the vitamin A value of different varieties of cassava. Biofortified cassava could alleviate some aspects of food insecurity in developing countries if widely adopted. [source] Changes in total carotenoid content at different stages of traditional processing of yellow-fleshed cassava genotypesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 12 2009Busie Maziya-Dixon Abstract The changes in content of total carotenoid at each stage of processing cassava storage roots were investigated with three improved yellow-fleshed cassava varieties (TMS 94/0006, TMS 01/1235 and TMS 01/1371) grown in 2005/2006 in a randomised complete block design with two replications at Ibadan, Nigeria. When the cassava roots were grated to a mash, results obtained indicate that there was a significant reduction in total carotenoid content for all the genotypes. The reduction was highest for TMS 01/1235 (1.20 ,g g,1), intermediate for TMS 01/1371 (0.78 ,g g,1) and least for TMS 94/0006 (0.35 ,g g,1). In most cases, we observed higher total carotenoid concentration, especially when the intermediate step involved pressing to remove excess water, and during roasting compared with the initial concentration in the raw cassava storage roots. In conclusion, grating, drying and cooking to a paste resulted in reduction of total carotenoid content, while roasting and pressing resulted in higher carotenoid concentration. A change in total carotenoid content during processing depends on variety, processing method, especially unit operation and the initial total carotenoid content of the variety. [source] Initial evaluation of a field-friendly extraction procedure for the enzymatic assay of cassava cyanogensINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 8 2007Gerard M. O'Brien Summary A novel ,field friendly' extraction procedure has been developed for the enzymatic colorimetric determination of cyanogenic potential (CNP) in fresh cassava root parenchyma. The novel procedure does not require electrical power or vacuum, and employs inexpensive lightweight equipment, making it suitable for remote field sites. Testing of the procedure involved ten fresh roots (24,80 mg kg,1 total CNP, as HCN, fresh basis). From the parenchyma of each root, one extract was made using the novel procedure, and a ,control' extract was made using a traditional laboratory-based procedure. Total CNP assay of the extracts indicated strong (y = mx) or very strong (y = mx + c) correlation of results obtained using the two procedures, while a very strong correlation (y = mx) was obtained for free HCN. Based on this preliminary evidence, the novel procedure is satisfactory at least for total CNP assay of fresh low-CNP cassava roots. [source] Identification of Three Strains of a Virus Associated with Cassava Plants Affected by Frogskin DiseaseJOURNAL OF PHYTOPATHOLOGY, Issue 11-12 2008L. A. Calvert Abstract Cassava Frogskin Disease (CFSD) can cause severe damage to cassava roots and is one of the most important diseases of cassava in Latin America. The principal objective of this study was to identify the causal agent of CFSD. Electron microscopy, viral purifications, double-stranded RNA (dsRNA) analysis, cloning, sequencing, rtPCR and hybridizations were carried out to characterize and associate a novel virus with the disease. Virus-like particles of 70 and 45 nm in diameter were found in affected cassava plants and partially purified preparations respectively. Nine species of dsRNA were associated with this disease and cDNA clones to six genomic segments were synthesized from the purified dsRNAs. The putative proteins predicted from the sequence of the cassava virus cDNA clones have similarity with the P1, P2, P3, P4, P5 and P10 proteins of Rice ragged stunt virus (RRSV). Phylogenic analysis confirmed that this virus is a member of the family Reoviridae and is most closed related to RRSV. Hybridization analyses of dsRNA identified S1, S2, S3, S4, S5 and S10 genomic segments in the CFSD-affected plants, but not in healthy controls. Additionally, 26 isolates were compared using a portion of the putative polymerase gene. The virus was detected in all 26 isolates, and they were classified into three distinct races. The association of this virus with CFSD was strengthened by the detection of this virus in diseased plants collected from different locations throughout Colombia. [source] The retail market for fresh cassava root tubers in the European Union (EU): the case of Copenhagen, Denmark , a chemical food safety issue?JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 2 2010Lotte Kolind-Hansen Abstract BACKGROUND: A number of retail shops in Copenhagen sell fresh cassava roots. Cassava roots contain the toxic cyanogenic glucoside linamarin. A survey was made of the shop characteristics, origin of the roots, buyers, shop owner's knowledge of toxicity levels, and actual toxicity levels. RESULTS: Shops selling fresh cassava were shown mostly to be owned by persons originating in the Middle East or Afghanistan, buyers were found to predominantly be of African origin, and sellers' knowledge concerning the potential toxicity was found to be very restricted. Seventy-six per cent of the roots purchased had a total cyanogenic potentials (CNp) above the 50 mg HCN equivalents kg,1 dry weight (d.w.) proposed as acceptable by an EU working group. Two of 25 roots purchased had CNp higher than 340 mg HCN eq. kg,1 d.w. CONCLUSION: The EU has previously made risk assessments concerning cassava and cyanogenic compounds. In the light of the conclusions drawn, the EU needs to make decisions about how to deal with the regulation and control of fresh cassava roots imported to the European food market. Also cassava root products and cassava leaves should be considered. Copyright © 2009 Society of Chemical Industry [source] Nutritional Value of Cassava for Use as a Staple Food and Recent Advances for ImprovementCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 3 2009Julie A. Montagnac ABSTRACT:, Cassava is a drought-tolerant, staple food crop grown in tropical and subtropical areas where many people are afflicted with undernutrition, making it a potentially valuable food source for developing countries. Cassava roots are a good source of energy while the leaves provide protein, vitamins, and minerals. However, cassava roots and leaves are deficient in sulfur-containing amino acids (methionine and cysteine) and some nutrients are not optimally distributed within the plant. Cassava also contains antinutrients that can have either positive or adverse effects on health depending upon the amount ingested. Although some of these compounds act as antioxidants and anticarcinogens, they can interfere with nutrient absorption and utilization and may have toxic side effects. Efforts to add nutritional value to cassava (biofortification) by increasing the contents of protein, minerals, starch, and ,-carotene are underway. The transfer of a 284 bp synthetic gene coding for a storage protein rich in essential amino acids and the crossbreeding of wild-type cassava varieties with Manihot dichotoma or Manihot oligantha have shown promising results regarding cassava protein content. Enhancing ADP glucose pyrophosphorylase activity in cassava roots or adding amylase to cassava gruels increases cassava energy density. Moreover, carotenoid-rich yellow and orange cassava may be a foodstuff for delivering provitamin A to vitamin A,depleted populations. Researchers are currently investigating the effects of cassava processing techniques on carotenoid stability and isomerization, as well as the vitamin A value of different varieties of cassava. Biofortified cassava could alleviate some aspects of food insecurity in developing countries if widely adopted. [source] | ||||||||||