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Cassava
Terms modified by Cassava Selected AbstractsEFFECT OF LACTIC ACID FERMENTATION OF CASSAVA ON FUNCTIONAL AND SENSORY CHARACTERISTICS OF FUFU FLOURJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2008A.O. SOBOWALE ABSTRACT The effects of lactic acid fermentation of cassava on the functional and sensory characteristic of fufu flour were investigated. Two strains of Lactobacillus plantarum were used as starter cultures for the fermentation of cassava to fufu for 96 h. The resultant wet fufu samples were dried at 65C in a cabinet dryer for 48 h, and were analyzed for functional and sensory characteristics. Fermentation reduced the water-binding capacity of the fufu flour from 176.6% to between 118 and 125%. The pasting characteristics of the traditional and starter culture-fermented fufu flour samples were not significantly different from that of the unfermented cassava flour. When subjected to sensory evaluation, the traditional and starter culture-fermented cassava fufu flour were not significantly different in terms of color, odor and texture, but the cassava fufu flour produced, using starter culture SL19, had the highest overall acceptability (P < 0.05). PRACTICAL APPLICATIONS Traditionally, processing of cassava to fufu is usually carried out by using the old stock from a previous fermentation to initiate the fermentation of a new batch. This old method usually results in fufu that has a strong odor that may not be acceptable to some consumers. The use of starter culture like Lactobacillus plantarum will reduce the strong odor of fufu; this will increase its acceptability by consumers and ensure the overall quality. Also, the functional properties of fufu are not affected. The development of lactobacilli strains could help in optimizing the traditional processes, therefore increasing the economic returns. [source] EFFECT OF NaCl AND WATER CONTENT ON EXPANSION AND COLOR OF CASSAVA AND POTATO STARCHES ON BAKINGJOURNAL OF TEXTURE STUDIES, Issue 6 2009A. FARAHNAKY ABSTRACT Due to the importance of the role of NaCl in starch-based systems, the effect of NaCl and water content on specific volume, color parameters and moisture loss of cassava and potato starches was studied and response surface methodology was used to find and estimate any nonlinearity between the parameters under study. Glass transition (Tg) is one of the main factors determining the quality parameters of toasted and baked samples. Therefore, Tg of two starch systems (cassava and potato) at low water levels (<20%) as affected by NaCl and water content was investigated. Using experimental modeling, equations were obtained to relate expansion, color change and moisture loss of baked samples to salt level and water content. Differential scanning calorimetry-measured Tg showed that NaCl had negative impact on glass/rubber transition temperature of starch,salt mixtures compared with the samples without NaCl. This could have practical implications in baking, toasting and extrusion processing of starch-based systems. PRACTICAL APPLICATION Due to concerns over health-related issues of high intake of salt by the consumers, recently, the reduction of salt in different food products has become the focus of many industrial projects, conferences and workshops. In breakfast cereals, other than starch type, other added ingredients such as sugar and salt can have profound effects on the physical characteristics of final products. The inclusion of salt in breakfast cereals has some important technological roles, e.g., structure formation and flavor and color generation. Salt plays a key role in the expansion of low-moisture extruded starch-based products. Using the findings of this paper, one may quantify the effects of salt level on expansion and color of baked, toasted or extruded starch-based cereal products and relate the changes to the glass rubber transition of the system. [source] Soils Utilized for Gardens by Tukanoans in Northwestern Amazonia and their Impact on Cassava (Manihot esculenta Crantz) Cultivar SelectionCULTURE, AGRICULTURE, FOOD & ENVIRONMENT, Issue 2 2002Assistant Professor Warren Wilson First page of article [source] Cause and effect relationship of malnutrition with idiopathic chronic pancreatitis: Prospective case,control studyJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2008Shallu Midha Abstract Background and Aim:, Patients with chronic pancreatitis are often malnourished. The role of malnutrition in the pathogenesis of chronic pancreatitis is unclear. The aim of the present article was to study prospectively the cause and effect relationship of malnutrition with idiopathic chronic pancreatitis in a case,control study. Methods:, Consecutive patients with chronic pancreatitis underwent anthropometry, nutritional and dietary assessments. For dietary assessment, food frequency questionnaire and 24-hour dietary recall methods were used. Primary outcome measure was cause and effect relationship of malnutrition with idiopathic chronic pancreatitis. Results:, Of 201 patients with chronic pancreatitis, 120 had idiopathic chronic pancreatitis (mean age 29.60 years, 74 males) who formed the study group. None of the patients consumed cassava. The nutritional status and dietary intake of the patients before the onset of chronic pancreatitis were comparable with those of controls with 20.6% of patients and 22.5% of controls being malnourished (body mass index [BMI] < 18.5). After the onset of chronic pancreatitis, 56.5% of patients lost weight and significantly more patients became malnourished compared with controls (45.8% vs 22.5%; P < 0.001). The causes of weight loss were diabetes, higher calories from proteins, and pseudocyst. Conclusion:, Malnutrition was not a cause of idiopathic chronic pancreatitis and weight loss occurred as an effect of chronic pancreatitis. Cassava was not found to be a cause of idiopathic chronic pancreatitis. [source] Effects of Brown Streak Virus Disease on Yield and Quality of Cassava in TanzaniaJOURNAL OF PHYTOPATHOLOGY, Issue 7-8 2001R. J. Hillocks Abstract Brown streak virus disease is the most important biotic constraint to cassava production in the coastal areas of southern Tanzania. Symptoms include foliar chlorosis and sometimes stem lesions. The disease also affects the tuberous roots which develop a yellow/brown, dry, corky necrosis within the starch-bearing tissues, sometimes accompanied by pitting and distortion, that is visible externally. The foliar symptoms of the disease often do not greatly affect plant growth, although the most sensitive cultivars may be stunted and defoliated. The main impact of the disease on the crop is by causing root necrosis. Field experiments were conducted at two sites in Tanzania to determine the effect of the disease on yield and quality of the roots. Cassava brown streak disease (CBSD) decreased root weight and patches of root necrosis made roots unmarketable, although the unaffected parts might still have been suitable for home consumption. The disease therefore has two effects, one on total root yield and one on root quality, which affects marketability. The field trials showed that CBSD can decrease root weight in the most sensitive cultivars by up to 70%. The length of time between the appearance of foliar symptoms and the development of root necrosis is a varietal characteristic. In the most susceptible cultivars, root necrosis may appear within 6 months of planting cuttings derived from symptomatic mother plants. A local cultivar known as cv. Nachinyaya exhibited a form of tolerance to CBSD in which foliar symptoms appeared but the development of root necrosis was delayed allowing the full yield potential to be realized. [source] Rising African cassava production, diseases due to high cyanide intake and control measuresJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2008Dulce Nhassico Abstract Cassava is the staple food of tropical Africa and its production, averaged over 24 countries, has increased more than threefold from 1980 to 2005, and the population has more than doubled over that time compared with a 1.5 times increase worldwide. Agriculturally, cassava performs very well but the roots and leaves contain cyanogenic glucosides that are dangerous to human health. These cyanogens sometimes produce acute intoxication leading to death, they exacerbate goitre and cretinism in iodine-deficient regions, cause konzo and are implicated in the occurrence of tropical ataxic neuropathy and stunting of children. Konzo is an irreversible paralysis of the legs with many thousands of cases, mainly amongst children, in Mozambique, Tanzania, Democratic Republic of Congo, Cameroon, Central African Republic and probably other tropical African countries. Attempts to alleviate cassava cyanide toxicity have included the development of an information network and distribution in developing countries of picrate kits, which measure total cyanide in cassava and urinary thiocyanate. A simple wetting method that reduces total cyanide in cassava flour three- to sixfold has been successfully field tested and is being introduced in Mozambique. Transgenic technology shows promise in increasing the rate of loss of cyanide from roots during processing. World health and agricultural bodies should pay more attention to emerging health problems associated with toxicity of cyanogens in cassava. Copyright © 2008 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] Microevolution in agricultural environments: how a traditional Amerindian farming practice favours heterozygosity in cassava (Manihot esculenta Crantz, Euphorbiaceae)ECOLOGY LETTERS, Issue 2 2005Benoît Pujol Abstract We demonstrate a novel case of selection for heterozygosity in nature, involving inadvertent human selection on a population of domesticated plants. Amerindian farmers propagate cassava (Manihot esculenta) clonally by cuttings. Seedlings also appear spontaneously in fields, and farmers allow them to grow, later using some for cuttings. These ,volunteers' contribute new genotypes. However, many are inbred, whereas multiplied clones are highly heterozygous. We demonstrate the selective retention of heterozygous volunteers. When farmers weeded fields, they killed small volunteers, but retained large ones. Plant size and heterozygosity were correlated, and both increased after weeding. The process we document allows maintenance of genotypically diverse and heterozygous clonal stocks. Demonstrating heterosis in nature usually requires large sample sizes, but novel features of our system allowed escape of this constraint. Traditional agroecosystems offer unusual opportunities for the microevolutionary studies required to give on-farm conservation of genetic resources a solid scientific basis. [source] Mating compatibility, life-history traits, and RAPD-PCR variation in Bemisia tabaci associated with the cassava mosaic disease pandemic in East AfricaENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2001M.N. Maruthi Abstract The pandemic of a severe form of cassava mosaic virus disease (CMVD) in East Africa is associated with abnormally high numbers of its whitefly vector, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). To determine whether a novel B. tabaci biotype was associated with the CMVD pandemic, reproductive compatibility, fecundity, nymphal development, and random amplified polymorphic DNA (RAPD) variability were examined in, and between, B. tabaci colonies collected from within the CMVD pandemic and non-pandemic zone in Uganda. In a series of reciprocal crosses carried out over two generations among the six CMVD pandemic and four non-pandemic zone cassava B. tabaci colonies, there was no evidence of mating incompatibility. All the crosses produced both female and male progeny in the F1 and F2 generations, which in a haplo-diploid species such as B. tabaci indicates successful mating. There also were no significant differences between the sex ratios for the pooled data of experimental crosses, between individuals from two different colonies and control crosses between individuals from the same colony. Only one instance of mating incompatibility occurred in a control cross between cassava B. tabaci from Uganda and cotton B. tabaci from India. Measures of fecundity of the pandemic and non-pandemic zone B. tabaci on four cassava varieties showed no significant differences in their fecundity, nymphal development or numbers surviving to adult eclosion. Cluster analysis of 26 RAPD bands using six 10-mer primers was concordant with the mating results, grouping the pandemic and non-pandemic zone colonies into a single large group, also including a B. tabaci colony collected from cassava in Tanzania. These results suggest that it is unlikely that the severe CMVD pandemic in East Africa is associated with a novel and reproductively isolated B. tabaci biotype. [source] Influence of parasitism by encyrtid parasitoids on the feeding behaviour of the cassava mealybug Phenacoccus herreniENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2001P.-A. Calatayud Abstract Three encyrtid parasitoids Apoanagyrus (Epidinocarsis) diversicornis, Aenasius vexans, and Acerophagus coccois (Hymenoptera: Encyrtidae) are used to control the cassava mealybug Phenacoccus herreni Cox & Williams (Sternorrhyncha: Pseudococcidae), an important pest of cassava in South America. The influence of parasitism on the feeding behaviour of mealybugs was studied by observing honeydew secretion and by the electrical penetration graph technique (EPG, DC-system). Honeydew secretions were observed after parasitism until mummy transformation. No strong EPG parameter differences were found between parasitised and control insects. All results indicated that parasitised mealybugs keep feeding on the phloem sap after parasitism until mummy transformation. The main influence of parasitism on EPG parameters is the appearance of a new pattern resembling the E2 pattern at the extracellular level and labelled H. This pattern was also produced with control insects located on an unfavourable feeding site and could be associated with a stress response. It might be related to the still unclear E(c) pattern of aphids. The relationship of H to stylet activities is discussed. [source] Erosion and Nutrient Loss on Sloping Land under Intense Cultivation in Southern VietnamGEOGRAPHICAL RESEARCH, Issue 1 2008NGUYEN VAN DE Abstract To help improve the well-being of the local people, a joint Vietnamese-UK team set out to establish a way of estimating soil and nutrient losses under different land management scenarios, using field data extrapolated through remote sensing and GIS, to obtain catchment-wide estimates of the impact of land cover change. Immigration from remote provinces to the Dong Phu District of Binh Phuóc Province, about 120 km north of Ho Chi Minh City, has led to disruption of soil surface stability on easily eroded clayey sandstones, creating rapid nutrient depletion that affects crop yields and siltation in the channel of the Rach Rat river downstream. The poor farmers of the areas see crop yields drop dramatically after two or three years of cultivation due to the fertility decline. Soil loss varies dramatically between wet season and dry season and with ground cover. Erosion bridge measurements showed a mean loss of 85.2 t ha,1 y,1 under cassava saplings with cashew nuts, 43.3 t ha,1 y,1 on uncultivated land and 41.7 t ha,1 y,1 under mature cassava. The rates of erosion were higher than those reported in many other parts of Vietnam, reflecting the high erodibility of the friable sandy soils on the steep side-slopes of the Rach Rat catchment. However, although the actual measurements provide better soil loss data than estimates based on the parameters of soil loss equations, a large number of measurement sites is needed to provide adequate coverage of the crop and slope combinations in this dissected terrain for good prediction using GIS and remote sensing. [source] Thermo-physical properties of composite bread dough with maize and cassava floursINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2010Olufunmilola Olaitan Oladunmoye Summary Composite wheat,cassava and wheat,maize flours were produced in ratio 100:0. 60:40, 50:50, 40:60 and 0:100 respectively. Thermo-physical properties of bread dough were determined. For wheat ,cassava composite bread dough, moisture content ranged between 44.02 ± 2.04 to 51.31 ± 2.99% dry basis (db), density (1035.2 ± 20.4 to 975.6 ± 12.6 kg m,3), specific heat capacity (2.51 ± 0.61 to 3.01 ± 0.42 kJ kg,1 K) and thermal conductivity (0.362 ± 0.13 to 0.473 ± 0.12 W mK,1). While wheat,maize mixture gave 44.14 ± 1.94 to 45.09 ± 1.26%(db) of moisture content, 981.4 ± 16.3,960.4 ± 22.5 kg m,3 density, 1.77 ± 0.17,2.61 ± 0.63 kJ kg,1 K specific heat capacity and 0.36 ± 0.07,0.39 ± 0.02 W mK,1 thermal conductivity. Effects of substitutions was significant on moisture content and thermal conductivity of dough while non significant influence was recorded on density and specific heat capacity at P < 0.05. [source] The influence of pH and digestion with commercial enzymes on calcium adsorption in casabeINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2006Petra Beatriz Navas Summary The Ca2+ binding capacity of a sample of casabe made from cassava (Manihot esculenta) was evaluated by using adsorption isotherms after a digestion process with commercial enzymes. It was found that enzymatic treatment increased the ability of vegetable material to retain calcium and to release endogenous mineral ions as a consequence of possible modifications to the carbohydrate matrix. Untreated casabe did not release mineral ions. pH also influenced the retention of Ca2+: at pH 4.5 release was the main process but adsorption increases with alkalinity up to pH 8.5. The Ca concentrations at which neither adsorption nor release occurred [Ca2+]e were as follows: 5.2 mm (pH 4.5), 3.5 mm (pH 7.1), and 0.63 mm (pH 8.5). The pH effect was explained by an increase in the density of negatively charged functional groups produced by ionization reactions at pH below the point of zero net charge (pHo) which was evaluated by using the Gouy,Chapman double layer model. Values of pHo were 6.4 for raw material and 4.1 after digestion with enzymes. In both cases, the density of positively charged sites below pHo was much higher that the density of negatively charged sites above pHo. [source] Cassava starch functional properties by etherification , hydroxypropylationINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 6 2006Cláudio S. Schmitz Summary Starches are important food biopolymers with gelling properties that are well explored by the food industry for texture and physical food characteristic control. Brazil contributes to a large part of the starches produced world wide, but the modified starches used are imported and expensive. The objective of this work was to develop a hydroxypropylated starch from cassava starch, at a lower price and in conditions in accordance with Brazilian reality. Dihydroxypropylstarch (DHPS) was produced with a less expensive and less harmful substituting molecule, chloropropylene glycol. DHPS physical chemistry properties, retrogradation and micro structural characteristics were studied and compared with native corn, cassava starches and a commercial hydroxypropylated (HPS) cassava starch, with an extensive use in the food industry. DHPS showed the highest values for swelling power and viscosity, low retrogradation and higher freezing,thawing stability, compared with HPS, cassava and native corn starches. The microstructure of DHPS remained unmodified when compared with commercial HPS. Retrogradation and physical chemistry properties are superior to DHPS, which would indicate its use in industrial food production. [source] Construction of Recombinant Escherichia coli Catalysts which Simultaneously Express an (S)-Oxynitrilase and Different Nitrilase Variants for the Synthesis of (S)-Mandelic Acid and (S)-Mandelic Amide from Benzaldehyde and CyanideADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2009Olga Sosedov Abstract Recombinant Escherichia coli strains were constructed which simultaneously expressed the genes encoding the (S)-oxynitrilase from cassava (Manihot esculenta) together with the wild-type or a mutant variant of the arylacetonitrilase from Pseudomonas fluorescens EBC191 in a single organism under the control of a rhamnose-inducible promoter. The whole cell catalysts obtained converted benzaldehyde and potassium cyanide in aqueous media at pH,5.2 mainly to (S)-mandelic acid and/or (S)-mandelic amide and synthesized only low amounts of the corresponding (R)-enantiomers. The conversion of benzaldehyde and potassium cyanide (KCN) by a whole-cell catalyst simultaneously expressing the (S)-oxynitrilase and the wild-type nitrilase resulted in a ratio of (S)-mandelic acid to (S)-mandelic amide of about 4:3. This could be explained by the strong nitrile hydratase activity of the wild-type nitrilase with (S)-mandelonitrile as substrate. The relative proportion of (S)-mandelic amide formed in this system was significantly increased by coexpressing the (S)-oxynitrilase with a carboxy-terminally truncated variant of the nitrilase. This whole-cell catalyst converted benzaldehyde and KCN to mandelic amide and mandelic acid in a ratio of about 9:1. The ee of the (S)-mandelic amide formed was calculated to be >95%. [source] Evaluation of Serangium n. sp. (Col., Coccinellidae), a predator of Bemisia tabaci (Hom., Aleyrodidae) on cassavaJOURNAL OF APPLIED ENTOMOLOGY, Issue 2 2007P. Asiimwe Abstract, The potential of a new, previously unidentified Serangium species (Col., Coccinellidae) to control the high Bemisia tabaci (Gennadius) (Hom., Aleyrodidae) populations on cassava was evaluated. Field and laboratory studies were carried out to determine the abundance and feeding capacity of this Serangium species feeding on B. tabaci on cassava. Serangium nymphs and adults were most abundant in cassava fields late in the season, rising sharply from 5 months after planting (MAP) to a peak at 7,8 MAP. Pre-imaginal development averaged 21.2 days and was longest in eggs and shortest in the L1 instar. Mean total prey consumption of immature Serangium increased with the stage of development with the lowest consumption in the L1 instar and highest in the L4 instar. Mean daily consumption was lowest on the first day after hatching in the L1 instar and rose to a peak on the 13th day after hatching in the L4 instar. Each Serangium larva consumed a mean of over 1000 nymphs during its entire development. These results have demonstrated the potential of this Serangium species to control B. tabaci populations on cassava. [source] Nutritional evaluation of various plant protein sources in diets for Asian sea bass Lates calcariferJOURNAL OF APPLIED ICHTHYOLOGY, Issue 2 2000By P. S. Eusebio A biological assay was conducted to evaluate the suitability of various leguminous seed meals and leaf meals as dietary protein sources for Asian sea bass, Lates calcarifer. In the growth experiment, fish (initial mean weight ±,standard error (SE) of 3.8 ± 0.5 g) were fed isonitrogenous and isocaloric diets containing test ingredients to replace 13,18% of the diet. The same diet formulations were used in a digestibility experiment, except that 1% Cr2O3 was added as an external indicator. The growth of the control fish was comparable to fish fed leguminous seed meal-based diets, and better than those given leaf meal-based diets. The control diet had the highest apparent protein digestibility (APD) value. No significant differences were observed between the APD of white cowpea (Vigna unguiculata), green mungbean (V. radiata) and papaya (Carica papaya) leaf meal-based diets. However, the cassava (Manihot esculenta) leaf meal-based diet had the lowest APD value. The present findings suggest that white cowpea and green mungbean meals can be used as protein sources in practical diets to replace 18% of the sea bass diet without affecting their growth. [source] Size asymmetry in intraspecific competition and the density-dependence of inbreeding depression in a natural plant population: a case study in cassava (Manihot esculenta Crantz, Euphorbiaceae)JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2006B. PUJOL Abstract The effects of competition on the genetic composition of natural populations are not well understood. We combined demography and molecular genetics to study how intraspecific competition affects microevolution in cohorts of volunteer plants of cassava (Manihot esculenta) originating from seeds in slash-and-burn fields of Palikur Amerindians in French Guiana. In this clonally propagated crop, genotypic diversity is enhanced by the incorporation of volunteer plants into farmers' stocks of clonal propagules. Mortality of volunteer plants was density-dependent. Furthermore, the size asymmetry of intraspecific competition increased with local clustering of plants. Size of plants was correlated with their multilocus heterozygosity, and stronger size-dependence of survival in clusters of plants, compared with solitary plants, increased the magnitude of inbreeding depression when competition was severe. The density-dependence of inbreeding depression of volunteer plants helps explain the high heterozygosity of volunteers that survive to harvest time and thus become candidates for clonal propagation. This effect could help favour the maintenance of sex in this ,vegetatively' propagated crop plant. [source] EFFECT OF LACTIC ACID FERMENTATION OF CASSAVA ON FUNCTIONAL AND SENSORY CHARACTERISTICS OF FUFU FLOURJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 4 2008A.O. SOBOWALE ABSTRACT The effects of lactic acid fermentation of cassava on the functional and sensory characteristic of fufu flour were investigated. Two strains of Lactobacillus plantarum were used as starter cultures for the fermentation of cassava to fufu for 96 h. The resultant wet fufu samples were dried at 65C in a cabinet dryer for 48 h, and were analyzed for functional and sensory characteristics. Fermentation reduced the water-binding capacity of the fufu flour from 176.6% to between 118 and 125%. The pasting characteristics of the traditional and starter culture-fermented fufu flour samples were not significantly different from that of the unfermented cassava flour. When subjected to sensory evaluation, the traditional and starter culture-fermented cassava fufu flour were not significantly different in terms of color, odor and texture, but the cassava fufu flour produced, using starter culture SL19, had the highest overall acceptability (P < 0.05). PRACTICAL APPLICATIONS Traditionally, processing of cassava to fufu is usually carried out by using the old stock from a previous fermentation to initiate the fermentation of a new batch. This old method usually results in fufu that has a strong odor that may not be acceptable to some consumers. The use of starter culture like Lactobacillus plantarum will reduce the strong odor of fufu; this will increase its acceptability by consumers and ensure the overall quality. Also, the functional properties of fufu are not affected. The development of lactobacilli strains could help in optimizing the traditional processes, therefore increasing the economic returns. [source] PROCESSING AND ACCEPTABILITY OF FRIED CASSAVA BALLS ("AKARA-AKPU") SUPPLEMENTED WITH MELON AND SOYBEAN FLOURSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2007CHIEMELA ENYINNAYA CHINMA ABSTRACT The processing and acceptability of fried cassava balls ("Akara-akpu") supplemented with melon and soybean flours were studied. Cassava flour, defatted soybean flour and cassava mash were produced. Some functional and chemical properties of the flours were determined. Akara-akpu prepared from 100% cassava mash served as control; 100% cassava flour, 80% cassava flour + 20% defatted soybean and 70% cassava flour + 30% defatted melon flour were prepared. Akara-akpu balls were subjected to chemical and physical analyses. Akara-akpu prepared from composite flour blends had higher protein, fat, ash and energy value than Akara-akpu from 100% cassava mash. The cyanide content and degree of starch gelatinization of Akara-akpu prepared from 100% cassava mash (control) were higher than Akara-akpu prepared from cassava mash plus composite flour blends. There was a significant difference (P , 0.05) in weight and yield between Akara-akpu prepared from 100% cassava mash (control) and cassava mash plus composite flour blends. There was no significant difference (P , 0.05) in volume between Akara-akpu made from control sample and those cassava plus composite flour blends. [source] Environment and host-plant genotype effects on the seasonal dynamics of a predatory mite on cassava in sub-humid tropical AfricaAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2009Christine Zundel Abstract 1,In tropical dry seasons, survival of small arthropods such as predatory mites is often negatively affected by low relative humidity (RH). For species that do not diapause or migrate to refuges, the ability of the habitat to mitigate climatic conditions becomes crucial. 2,The relative effect of macro-habitat (dry grassland hill, humid multiple cropping area, humid riparian forest) and microhabitat (host-plant genotypes with hairy, semi-hairy and glabrous apices) on the seasonal dynamics of the phytoseiid mite Typhlodromalus aripo, a predator of Mononychellus tanajoa on cassava, was examined in a field experiment during a dry season. The effect of RH and plant genotype on T. aripo egg survival was determined in an environment control chamber. 3,Predator abundance was higher in humid multiple cropping areas and on hairy cassava compared with the other habitat types and cassava genotypes. 4,Discriminant and regression analyses showed that the predator's dry season persistence was related to high RH, high plant vigour and hairy apices, but not to prey abundance. 5,In the controlled climate experiment, the effect of host-plant morphology was evident only at the intermediate RH level of 55%. An effect of apex hairiness was not found. 6,It is concluded that the effect of genotype on T. aripo persistence diminishes under low RH conditions, and that supportive effects of apex hairs become effective only in the field, probably through protection from wind and/or intraguild predation. Humid multiple cropping areas planted with hairy and vigorous cassava genotypes are suitable dry season reservoirs for T. aripo. [source] Cause and effect relationship of malnutrition with idiopathic chronic pancreatitis: Prospective case,control studyJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2008Shallu Midha Abstract Background and Aim:, Patients with chronic pancreatitis are often malnourished. The role of malnutrition in the pathogenesis of chronic pancreatitis is unclear. The aim of the present article was to study prospectively the cause and effect relationship of malnutrition with idiopathic chronic pancreatitis in a case,control study. Methods:, Consecutive patients with chronic pancreatitis underwent anthropometry, nutritional and dietary assessments. For dietary assessment, food frequency questionnaire and 24-hour dietary recall methods were used. Primary outcome measure was cause and effect relationship of malnutrition with idiopathic chronic pancreatitis. Results:, Of 201 patients with chronic pancreatitis, 120 had idiopathic chronic pancreatitis (mean age 29.60 years, 74 males) who formed the study group. None of the patients consumed cassava. The nutritional status and dietary intake of the patients before the onset of chronic pancreatitis were comparable with those of controls with 20.6% of patients and 22.5% of controls being malnourished (body mass index [BMI] < 18.5). After the onset of chronic pancreatitis, 56.5% of patients lost weight and significantly more patients became malnourished compared with controls (45.8% vs 22.5%; P < 0.001). The causes of weight loss were diabetes, higher calories from proteins, and pseudocyst. Conclusion:, Malnutrition was not a cause of idiopathic chronic pancreatitis and weight loss occurred as an effect of chronic pancreatitis. Cassava was not found to be a cause of idiopathic chronic pancreatitis. [source] Diffusion and spillover of new technology: a heterogeneous-agent model for cassava in West AfricaAGRICULTURAL ECONOMICS, Issue 2 2006Michael E. Johnson Positive mathematical programming; Technology adoption; Technical change Abstract Understanding what determines the geographic spread of innovations can help guide the funding and implementation of research and extension programs. Our approach uses household survey data as model parameters, to simulate behavior across the entire surveyed population and avoid the aggregation bias associated with representative-farm models. Such a "heterogeneous agent" approach allows us to infer the distribution of a technology's impacts across one set of households, and predict the potential for spreading to another set that shares similar characteristics with respect to natural resource endowments and farming systems. We apply the technique to new cassava varieties in West Africa, finding a strongly poverty-alleviating impact, with substantial spillover potential from Nigeria to neighboring countries. [source] A livelihood from the forest: gendered visions of social, economic and environmental change in Southern CameroonJOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 8 2001Katrina Brown This paper explores divergent perceptions and experiences of social, economic and environmental change of villagers in Southern Cameroon arguing that the economic crisis has impacted very differently on men and women within the same community and within households. The analysis highlights shifts in cropping patterns towards increased food crops, especially cassava and plantain, for cash. Sources of livelihood for men have diversified in the face of economic crisis, whereas women have reduced room to manoeuvre. This results in women becoming increasingly dependent on utilizing non-timber forest products for cash in order to meet their livelihood needs. However pressures on forest are increasing for a number of reasons and access to land and trees is becoming constrained, so future benefits from forest products will be contingent on clear, well defined and enforced community property rights. Copyright © 2001 John Wiley & Sons, Ltd. [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] Rapid Screening Method of Cassava Cultivars for Resistance to Colletotrichum gloeosporioides f.sp. manihotisJOURNAL OF PHYTOPATHOLOGY, Issue 1 2002C. N. FOKUNANG An in vitro method for assessing cassava anthracnose disease (CAD) resistance was developed as a preliminary screen to a CAD-resistant breeding programme. Potato dextrose agar (PDA) media was amended by extracts from the stem cortex of 10 cassava cultivars (30001; 30572, 30211, 88/02549, 88/00695, 88/01336, 91/00344, 91/00313, 91/00684 and 91/00475), and assayed for efficacy of inhibition of the growth of Colletotrichum gloeosporioides f. sp. manihotis isolates (05FCN, 10FCN, 12FCN, and 18FCN). Morphological and physiological data indicated that there was a significant difference (P , 0.05), in mycelial growth, spore germination and sporulation among the four isolates on PDA amended with cassava stem extracts. Extracts from cassava cultivars 30211, 91/00684 and 91/00313 showed higher inhibition of germ tube development, mycelial growth and sporulation of the fungal isolates, whereas cultivars 88/02549 and 88/01336 showed the least inhibition. The 10 cultivars were further tested in both greenhouse and field conditions, under disease pressure for two planting seasons, to corroborate resistance to the fungus as observed in vitro. Greenhouse and field trials with the 10 cassava cultivars showed a significant difference (P , 0.05) in CAD resistance. Cultivars 88/02549 and 88/01336 were highly CAD-susceptible, as shown in the in vitro assays and confirmed in the greenhouse and field tests. The other eight cultivars were either resistant (30211, 91/00684), or moderately resistant (30572, 88/00695, 91/00475, 91/00344, 30001 and 91/00313) to CAD. The study shows that an in vitro screening assay of cassava for resistance to CAD could serve as a convenient preliminary screening technique to discriminate CAD-resistant from CAD-susceptible cassava cultivars. The in vitro screening method considerably reduces time and labour in comparison with the current screening techniques of cassava, which involve field planting, inoculation and evaluation. [source] EFFECT OF NaCl AND WATER CONTENT ON EXPANSION AND COLOR OF CASSAVA AND POTATO STARCHES ON BAKINGJOURNAL OF TEXTURE STUDIES, Issue 6 2009A. FARAHNAKY ABSTRACT Due to the importance of the role of NaCl in starch-based systems, the effect of NaCl and water content on specific volume, color parameters and moisture loss of cassava and potato starches was studied and response surface methodology was used to find and estimate any nonlinearity between the parameters under study. Glass transition (Tg) is one of the main factors determining the quality parameters of toasted and baked samples. Therefore, Tg of two starch systems (cassava and potato) at low water levels (<20%) as affected by NaCl and water content was investigated. Using experimental modeling, equations were obtained to relate expansion, color change and moisture loss of baked samples to salt level and water content. Differential scanning calorimetry-measured Tg showed that NaCl had negative impact on glass/rubber transition temperature of starch,salt mixtures compared with the samples without NaCl. This could have practical implications in baking, toasting and extrusion processing of starch-based systems. PRACTICAL APPLICATION Due to concerns over health-related issues of high intake of salt by the consumers, recently, the reduction of salt in different food products has become the focus of many industrial projects, conferences and workshops. In breakfast cereals, other than starch type, other added ingredients such as sugar and salt can have profound effects on the physical characteristics of final products. The inclusion of salt in breakfast cereals has some important technological roles, e.g., structure formation and flavor and color generation. Salt plays a key role in the expansion of low-moisture extruded starch-based products. Using the findings of this paper, one may quantify the effects of salt level on expansion and color of baked, toasted or extruded starch-based cereal products and relate the changes to the glass rubber transition of the system. [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] Rising African cassava production, diseases due to high cyanide intake and control measuresJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2008Dulce Nhassico Abstract Cassava is the staple food of tropical Africa and its production, averaged over 24 countries, has increased more than threefold from 1980 to 2005, and the population has more than doubled over that time compared with a 1.5 times increase worldwide. Agriculturally, cassava performs very well but the roots and leaves contain cyanogenic glucosides that are dangerous to human health. These cyanogens sometimes produce acute intoxication leading to death, they exacerbate goitre and cretinism in iodine-deficient regions, cause konzo and are implicated in the occurrence of tropical ataxic neuropathy and stunting of children. Konzo is an irreversible paralysis of the legs with many thousands of cases, mainly amongst children, in Mozambique, Tanzania, Democratic Republic of Congo, Cameroon, Central African Republic and probably other tropical African countries. Attempts to alleviate cassava cyanide toxicity have included the development of an information network and distribution in developing countries of picrate kits, which measure total cyanide in cassava and urinary thiocyanate. A simple wetting method that reduces total cyanide in cassava flour three- to sixfold has been successfully field tested and is being introduced in Mozambique. Transgenic technology shows promise in increasing the rate of loss of cyanide from roots during processing. World health and agricultural bodies should pay more attention to emerging health problems associated with toxicity of cyanogens in cassava. Copyright © 2008 Society of Chemical Industry [source] Effects of cassava processing methods on antinutritional components and health status of children,JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2002Omorogieva Ojo Abstract This study was conducted to evaluate cassava processing methods in Nigeria, its antinutritional components and the possible impact on the health status of children. The traditional method of cassava processing involved peeling of cassava tubers with a knife, manual grating, dewatering with logs of wood and/or stones, sieving with a cane-woven sieve and frying in a local metal fryer on a wood fire. In contrast, the modern method involved the use of knives for peeling, a mechanical grater, a hydraulic press for dewatering, iron sieves for sieving and an improved metal fryer for frying on a coal fire. The products of both methods included gari (accounting for 70% of Nigeria's total cassava consumption) and lafun. The intake of gari and other foods in 129 3,5-year-old children in Benin City, Nigeria was also assessed based on a food frequency questionnaire. The children were classified into normal and protein-deficient groups using lower/middle/upper-arm circumference and clinical features of malnutrition. Based on the number of households in villages around Benin City who were involved in cassava processing, 90% used the traditional processing method compared with 10% using the modern method, although the latter controlled the commercial production and sale of gari. There were significantly (P,<,0.05) higher intakes of protein and energy in normal compared with protein-deficient children, but the latter group obtained higher percentages of protein and energy from gari. In addition, the correlation between the amount of gari consumed and clinical scores of malnutrition was low (R2,<,0.2). This may be due to the children consuming gari from both methods and also from different sources. The average gari intake for these children was 320,g,day,1 and HCN levels may be as high as 10.24,mg,day,1. Some children who are exposed to these levels with poor nutritional status and lack of access to food varieties may develop sublethal effects in the short term. The higher protein intake by the normal children may also reduce the toxicity of HCN. We conclude that methods of processing cassava have profound effects on HCN retention and chemical composition of cassava products. In addition, the modern processing method is more efficient than the traditional method, with significantly reduced processing losses, labour input and levels of HCN. The HCN content in combination with the quantity and quality of protein in the diet has significant impact on the health status of children. Therefore, in susceptible children with poor nutritional status who consume inadequately processed cassava products with limited food choice, these may predispose them to the effects of HCN and thiocyanate. © 2002 Society of Chemical Industry [source] | |||||||||||||||||||||||||||||||||||||