When knowledge is not enough: barriers to recommended cassava processing in resource-constrained Kwango, Democratic Republic of Congo.

Background: Despite interventions to provide knowledge and improve bitter cassava processing in the Democratic Republic of Congo (DRC), cassava processing is sub-optimal. Consumption of insufficiently processed bitter cassava is associated with konzo, a neurological paralytic disease. Objective: This study aimed to explore barriers to appropriate cassava processing carried out by women in one deep rural, economically deprived area of DRC. Methods: A qualitative design used focus group discussions (FGDs) and participant observation to collect data among purposively selected women aged 15-61 years in Kwango, DRC. Data were analyzed using thematic analysis. Results: 15 FGDs with 131 women and 12 observations of cassava processing were undertaken. Observations indicated women did not follow recommended cassava processing methods. Although women were knowledgeable about cassava processing, two main barriers emerged: access to water and lack of money. Accessing water from the river to process cassava was burdensome, and the cassava was at risk of being stolen by soaking it in the river; therefore, women shortened the processing time. Cassava was not only used as a staple food but also as a cash crop, which led to households shortening the processing time to reach the market quickly. Conclusion: Knowledge about the risks of insufficient cassava processing and about safe processing methods alone is insufficient to change practices in a context of severe resource constraints. When planning nutrition interventions, it is critical to view the intervention in light of the socio-economic context in which the intervention will take place to improve its outcomes.

Protective efficacy of various carbonyl compounds and their metabolites, and nutrients against acute toxicity of some cyanogens in rats: biochemical and physiological studies.

Cyanogens are widely used in industries and their toxicity is mainly due to cyanogenesis. The antidotes for cyanide are usually instituted for the management of cyanogen poisoning. The present study reports the protective efficacy of 14 carbonyl compounds and their metabolites, and nutrients (1.0 g/kg; oral; +5 min) against acute oral toxicity of acetonitrile (ATCN), acrylonitrile (ACN), malononitrile (MCN), propionitrile (PCN), sodium nitroprusside (SNP), succinonitrile (SCN), and potassium ferricyanide (PFCN) in rats. Maximum protection index was observed for alpha-ketoglutarate (A-KG) against MCN and PCN (5.60), followed by dihydroxyacetone (DHA) against MCN (2.79). Further, MCN (0.75 LD50) caused significant increase in cyanide concentration in brain, liver and kidney and inhibition of cytochrome c oxidase activity in brain and liver, which favorably responded to A-KG and DHA treatment. Up-regulation of inducible nitric oxide synthase by MCN, PCN and SNP, and uncoupling protein by PCN and SNP observed in the brain was abolished by A-KG administration. However, no DNA damage was detected in the brain. MCN and SNP significantly decreased the mean arterial pressure, heart rate, respiratory rate and neuromuscular transmission, which were resolved by A-KG. The study suggests a beneficial effect of A-KG in the treatment of acute cyanogen poisoning.

Effect of genotype and genotype by environment interaction on total cyanide content, fresh root, and starch yield in farmer-preferred cassava landraces in Tanzania.

High starch yield is the most important trait for commercialized cassava starch production. Furthermore, cyanide present in cassava roots poses a health challenge in the use of cassava for food. Cassava genotypes have varying maturity periods that are also environmental dependent. This study aimed at identifying suitable cultivars and optimum time of harvest to maximize starch production across three environments. The study found significant difference between genotypes, locations, harvest period, and all the interactions (P ≤ 0.001) for all traits analyzed. Kiroba recorded high starch yields of 17.4, 12.7, and 8.2 t ha-1 at Chambezi, Amani, and Magadu, respectively. Kilusungu recorded highest cyanide content of 300-400 ppm across all locations but Kiroba recorded highest values of 800 ppm, 15 months after planting at Chambezi. Genotype by environment (GGE) biplot analysis revealed that Kiroba was a superior cultivar in terms of starch yield. Kilusungu recorded highest cyanide content and average starch yield, therefore suitable for use in starch production. The study confirmed effect of genotype and genotype by environment interaction, Kiroba cultivar was superior in terms of starch yield and maximum starch yield was obtained at 9 months after planting. Nyamkagile and Kibandameno had the lowest cyanide content across all environments.

Immunoglobulin isotype isolated from human placental extract does not interfere in complement-mediated bacterial opsonization within the wound milieu.

The wound healing potency of an aqueous extract of placenta can be evaluated through the presence of numerous regulatory components. The presence of glycans was detected by thin layer chromatography and fluorophore-assisted carbohydrate electrophoresis. Mass spectrometric analysis revealed the existence of multiple fragments of immunoglobulin G (IgG). IgG was present in the extract at a concentration of 25.2 ± 3.97 µg/ml. IgG possesses anti-complementary activity by diverting the complement activation from target surface. Thus, effect of placental IgG on complement-bacteria interaction was investigated through classical and alternative pathway and the preparation was ascertained to be safe with respect to their interference in the process of bacterial opsonization.

Mild method for removal of cyanogens from cassava leaves with retention of vitamins and protein.

A mild method was developed to remove cyanogens from cassava leaves that involved three consecutive steps (1) pounding, (2) standing for 2h in the sun or 5h in the shade in the tropics and (3) washing three times in water. Four cassava cultivars were used and the mean residual total cyanide content after steps 1, 2 and 3 was 28%, 12% and 1%, respectively. The pounded cassava leaves retained their bright green colour and texture. The traditional method for removing cyanogens from pounded cassava leaves is by boiling in water which removed all cyanogens in 10 min. However this method caused the pounded leaves to become dull green in colour and would cause considerable losses of vitamins, protein and methionine, which are already in short supply in the diet of poor village people in tropical Africa.

Biochemical, oxidative and histological changes caused by sub-acute oral exposure of some synthetic cyanogens in rats: ameliorative effect of α-ketoglutarate.

Time-dependent cyanide generation and acute toxicity of six different cyanogens were reported earlier, out of which malononitrile (MCN), propionitrile (PCN), and sodium nitroprusside (SNP) were found to be very toxic. We report here 14 d sub-acute toxicity of MCN, PCN, and SNP (oral; 1/10 LD50 daily) in female rats, and its amelioration by α-ketoglutarate (α-KG; oral; 5.26 mmol/kg; +5 min), a potential cyanide antidote. Significant decrease in white blood cells (PCN, SNP), platelets count (PCN), and blood glucose levels (MCN, PCN, SNP) was accompanied by elevated levels of alanine aminotransferase, lactate dehydrogenase (MCN, PCN, SNP), and aspartate aminotransferase (PCN, SNP). Oxidative damage was evidenced by diminished total antioxidant status in plasma and enhanced malondialdehyde levels in liver and kidney. This was accompanied by diminished levels of reduced glutathione, glutathione peroxidase, glutathione reductase, superoxide dismutase, and catalase in the brain, liver and kidney. We also observed increased levels of blood cyanide and thiocyanate, together with inhibition of cytochrome c oxidase and thiosulfate-sulfur transferase activities in total brain and liver homogenate, respectively. Cyanogens also produced several histological changes in all the organs studied. Post-treatment with α-KG significantly abrogated the toxicity of cyanogens, indicating its utility as an antidote for long-term cyanogen exposure.

Determinación d compuestos cianogénicos amigdaina y prunasina en semillas de almendras (prunus dulcis l) utilizando cromatografía liquida de alta resolución / Determination of cyanogenic compound amygdalin and prunasin in alond kernels (prrunus dulcis l) by using liquid chromatography / Detrminação de ccompostos cianogênicos amigdalina eprunasina em seementes e amêndoa (prunus dulcis miller) cromatografia líquida de alta resolução

El objetivo del presente trabajo fue aplicar un técnica para determinar y cuantificar por separado los compuestos cianogénicos que pueden estar presentes en la semilla de almendra madura (Prunus dulcis). Entre los métodos encontrados, se seleccionó la cromatografía de líquidos de alta resolución (HPLC), que permite la cuantificación de los glucósidos cianogénicos amigdalina y prunasina por separado, adecuando diferentes procedimientos de extracción como el tamaño de partículas que influye en el proceso de liofilización, donde a menor superficie mayor área de contacto para la sublimación. Se ensayaron muestras sin grasa y con grasa, utilizando los resultados con muestras con grasa, dados los resultados obtenidos. Se utilizó metanol 100% como extractante de los glucósidos cianogénicos, resultando una concentración de amigdalina máxima a partir un tiempo de extracción de 12 horas y como fase móvil acetonitrilo/agua (20:80), se obtiene amigdalina, con una concentración de 9,8 mg/100g de muestra seca. Los cromatogramas obtenidos presentan tiempo de retención (Tr), Amigdalina: 3,4 y Prunasina, 5,7, dos picos con excelente resolución, por lo tanto las condiciones anteriores se pueden utilizar para la identificación y cuantificación de amigdalina y prunasina.

The aim of this study was to apply a technique to identify and quantify separately also cyanogenic compounds that may be present in the mature seed almond (Prunus dulcis). Among the methods selected the chromatography of liquids of high resolution (HPLC), that permit the quantification of the glycosides for the separation process of Freeze Dry where there is less surface there is more contact to sublimation without fat samples, looking at the obtain results and supported by other investigations, the use of 100 % methanol extract as a mobile phase acetonitrile-water (80:20) the results obtained of the glycosides cyanogenics resulting in a concentration of maximum amygdalin from the time of extraction of twelve hours, amygdalin is obtained, with a concentration of 9,8 mg / 100 g of dry sample. The chromatograms obtained a time of retention (Tr), amygdalin 3,4 and prunasin 5,7 two peaks with excellent resolution, to the above conditions can be used for analysis by HPLC, identification and quantification of amygdalin and prunasina.

Neste trabalho, a técnica é aplicada para determinar e também para quantificar separadamente compostos cianogénicos que podem estar presentes na semente madura amêndoa (Prunus dulcis). Métodos encontrados é seleccionado de cromatografia líquida de alta eficiência (HPLC), que permite a quantificação dos glicosídeos separar adaptar diferentes técnicas de extracção, tais como o tamanho de partícula influencia o processo de liofilização, onde a área de superfície maior menor sublimação contacto com desengradas amostras de gordura e usando os resultados com amostras desengorduradas, Tendo em vista os resultados obtidos, e suportados por outras pesquisas metanol a 100 % foi usado como o agente de extracção e como fase móvel acetonitrilo/água (80:20) de glicósidos cianogénicos, resultando numa concentração elevada de amigdalina a partir de um tempo de extracção de 12 horas. Amigdalina é obtido, com uma concentração de 9,8 mg / 100 g de amostra seca. Os cromatogramas apresentados tempo de retenção (Tr), Amygdalin: 3,4 e prunasina 5,7 dois picos com excelente resolução, com as condições acima podem ser utilizados para a análise por HPLC. identificação e quantificação de amigdalina e prunasina.

Determinación de compuestos cianogénicos amigdalina y prunasina en semillas de almendras (prunus dulcis l) utilizando cromatografía liquida de alta resolución / Determination of cyanogenic compound amygdalin and prunasin in almond kernels (prunus dulcis l) by using liquid chromatography / Determinação de compostos cianogênicos amigdalina e prunasina em sementes e amêndoa (prunus dulcis miller) cromatografia líquida de alta resolução

El objetivo del presente trabajo fue aplicar un técnica para determinar y cuantificar por separado los compuestos cianogénicos que pueden estar presentes en la semilla de almendra madura (Prunus dulcis). Entre los métodos encontrados, se seleccionó la cromatografía de líquidos de alta resolución (HPLC), que permite la cuantificación de los glucósidos cianogénicos amigdalina y prunasina por separado, adecuando diferentes procedimientos de extracción como el tamaño de partículas que influye en el proceso de liofilización, donde a menor superficie mayor área de contacto para la sublimación. Se ensayaron muestras sin grasa y con grasa, utilizando los resultados con muestras con grasa, dados los resultados obtenidos. Se utilizó metanol 100% como extractante de los glucósidos cianogénicos, resultando una concentración de amigdalina máxima a partir un tiempo de extracción de 12 horas y como fase móvil acetonitrilo/agua (20:80), se obtiene amigdalina, con una concentración de 9,8 mg/100g de muestra seca. Los cromatogramas obtenidos presentan tiempo de retención (Tr), Amigdalina: 3,4 y Prunasina, 5,7, dos picos con excelente resolución, por lo tanto las condiciones anteriores se pueden utilizar para la identificación y cuantificación de amigdalina y prunasina.

The aim of this study was to apply a technique to identify and quantify separately also cyanogenic compounds that may be present in the mature seed almond (Prunus dulcis). Among the methods selected the chromatography of liquids of high resolution (HPLC), that permit the quantification of the glycosides for the separation process of Freeze Dry where there is less surface there is more contact to sublimation without fat samples, looking at the obtain results and supported by other investigations, the use of 100 % methanol extract as a mobile phase acetonitrile-water (80:20) the results obtained of the glycosides cyanogenics resulting in a concentration of maximum amygdalin from the time of extraction of twelve hours, amygdalin is obtained, with a concentration of 9,8 mg / 100 g of dry sample. The chromatograms obtained a time of retention (Tr), amygdalin 3,4 and prunasin 5,7 two peaks with excellent resolution, to the above conditions can be used for analysis by HPLC, identification and quantification of amygdalin and prunasina.

Neste trabalho, a técnica é aplicada para determinar e também para quantificar separadamente compostos cianogénicos que podem estar presentes na semente madura amêndoa (Prunus dulcis). Métodos encontrados é seleccionado de cromatografia líquida de alta eficiência (HPLC), que permite a quantificação dos glicosídeos separar adaptar diferentes técnicas de extracção, tais como o tamanho de partícula influencia o processo de liofilização, onde a área de superfície maior menor sublimação contacto com desengradas amostras de gordura e usando os resultados com amostras desengorduradas, Tendo em vista os resultados obtidos, e suportados por outras pesquisas metanol a 100 % foi usado como o agente de extracção e como fase móvel acetonitrilo/água (80:20) de glicósidos cianogénicos, resultando numa concentração elevada de amigdalina a partir de um tempo de extracção de 12 horas. Amigdalina é obtido, com uma concentração de 9,8 mg / 100 g de amostra seca. Os cromatogramas apresentados tempo de retenção (Tr), Amygdalin: 3,4 e prunasina 5,7 dois picos com excelente resolução, com as condições acima podem ser utilizados para a análise por HPLC. identificação e quantificação de amigdalina e prunasina.

Acute toxicity of some synthetic cyanogens in rats: time-dependent cyanide generation and cytochrome oxidase inhibition in soft tissues after sub-lethal oral intoxication.

Cyanogens include complex nitrile-containing compounds that can generate free cyanide of toxicological significance. Acute toxicity, time-dependent cyanide generation and cytochrome oxidase (CYTOX) inhibition in soft tissues, and urinary thiocyanate levels were measured after acute cyanogen intoxication in rats. Order of cyanogens in terms of LD50 was: malononitrile (MCN)>propionitrile (PCN)≈sodium nitroprusside (SNP)>acrylonitrile (ACN)>succinonitrile (SCN)>acetonitrile (ATCN) for oral, and SNP>MCN>ACN>PCN>SCN>ATCN for intraperitoneal and subcutaneous routes. MCN was most toxic by oral (LD50=66.4 mg/kg) and SNP by intraperitoneal (LD50=16.7 mg/kg) and subcutaneous (LD50=11.9 mg/kg) routes. Minimum survival time (25 min) was recorded after 4.0 LD50 ATCN. Order of cyanogens (0.75 LD50; oral) on the basis of maximum blood cyanide and time of peak cyanide generation were: ATCN>SNP>SCN>PCN>MCN>ACN, and MCN (30 min)

A modified ninhydrin micro-assay for determination of total cyanogens in plants.

Indirect quantification of total cyanogenic compounds (cyanogens) in plants was studied using a novel ninhydrin-based spectrophotometric micromethod. The ninhydrin-cyanide system obeys Beer's law in the range from 20 µg L(-1) to 800 µg L(-1) CN(-) with molar absorptivity ε=1.4×10(5) L mol(-1)cm(-1). Recovery at 100 µg L(-1) CN(-) was 100.5±0.1% and LOD and LOQ were 8 and 22 µg L(-1), respectively. The conditions for ninhydrin reagent preparation were discussed. The extraction and separation solutions, extraction and incubation time, and solvent volume were also investigated for maximum recovery of total cyanogens. 0.1% NaHCO3 was used as an extraction solvent for cyanide formed after enzymatic hydrolysis of cyanogens. The procedure was suitable for samples containing more than 90 mg CN(-)/100 g sample. When cyanogen concentrations were lower, the resulted cyanide was separated by microdiffusion in a Conway cell. Water was used as a hydrolysis medium and a donor solvent, while 2% Na2CO3 as an absorbing solution. Total cyanogen content in plum and almond kernels, as well as apple and flax seeds was determined.