Vitamin C stability in pineapple, guava and baobab juices under different storage conditions using different levels of sodium benzoate and metabisulphite

Vitamin C is one of the most important vitamins in fruit based products and its stability is very critical to guarantee its availability. Stability of vitamin C in baobab, guava and pineapple juices stored at room (22.4°C ± 1.3), chilling (-1.2°C ± 0.1) and freezing (-17.3°C ± 0.2) temperatures and using 0.05% sodium benzoate, 0.005% sodium metabisulphite and combined use of sodium benzoate and metabisulphite at 0.04 and 0.005% respectively was investigated. Results from the study revealed that both storage conditions and levels of the preservatives used significantly affected vitamin C stability in all the three types of juices used. Vitamin C contents were 74.4, 52.4 and 34.7 mg/100 mL for baobab, guava and pineapple juices on the first day of processing. Furthermore, vitamin C was found to be more stable in freezing storage conditions and the combined use of sodium benzoate and sodium metabisulphite at 0.04 and 0.005%, respectively was more effective in stabilizing vitamin C in the fruit juices than the other preservative levels used. It can be concluded that vitamin C stability in the three types of juices was influenced by storage temperature conditions, storage time and levels and types of preservatives used.Keywords: Stability, baobab, guava, pineapple, vitamin C, sodium benzoateAfrican Journal of Biotechnology Vol. 12(2), pp. 186-19

Effect of Cassava Flour Processing Methods and Substitution Level on Proximate Composition, Sensory Characteristics and Overall Acceptability of Bread Made from Wheat- Cassava Flour Blends

The consumption of bread is globally increasing. However, due to increased costs associated with production of bread from 100% wheat flour especially in developing countries, other cereal based flours are now being blended with wheat flour to produce bread. This study was carried out to assess the effect of using two differently processed cassava flour (fermented and unfermented) and substitution level on proximate composition, sensory characteristics and overall acceptability of bread made from wheat-cassava flour blends. Bread was made using wheat flour incorporated in fermented and unfermented cassava flour at the ratios of 100:0, 90:10 and 80:20 for wheat: cassava flour, respectively and baked using a Morphy Richards (serial number 20076019) bread maker. The results showed that both the cassava flour and cassava flour substitution levels significantly affected (p<0.05) proximate composition, sensory characteristics and overall acceptability of the bread. Regardless of flour type, increased cassava flour substitution progressively decreased the crude protein and fat contents while the ash content was increased. The trend in significant differences as a reflection of the effect of cassava flour type and substitution level for the bread sensory characteristics was not consistent. Bread made from the 100% wheat flour was not significantly different from breads made from the following cassava flour type and substitution levels: 10% fermented cassava flour, 10% unfermented flour and 20% unfermented cassava flour in colour, texture, aroma and taste. Significant differences were observed between bread made from the 100% wheat flour and breads from the following cassava type and substitution levels: 20% fermented cassava flour, 10% and 20% unfermented cassava flour in colour, texture, aroma and taste. Overall acceptability and index to volume were both significantly affected by the cassava flour type and substitution levels. In conclusion, cassava flour substitution levels in wheat-cassava flour blends for bread making should not exceed 10% regardless of how the cassava flour has been processed to ensure bread with improved proximate composition and acceptable sensory attributes.Keywords: bread, acceptability, proximate, sensory, cassav

Case Report: Treatment of metastatic germ cell tumor in a newly diagnised HIV infected man: use of BEP chemotherapy.

No Abstrac

Exposure of school children to aflatoxins and fumonisins through maize-based diets in school meals programme in Salima District, Malawi

Exposure to aflatoxins and fumonisins contaminated food poses threats to human health, including causation of cancer,  immunosuppression, impaired growth, respiratory problems, diarrhea, among others. This study was carried out to evaluate the levels of aflatoxins and fumonisins in maize-based porridge and the estimated intake levels of the contaminants among school going children in selected primary schools in Salima District, Malawi. A total of 496 children and 124 food handlers from 31 primary schools within three Extension Planning Areas(EPAs) under the School Meals Programmes were involved. Consumption and meal preparation data were collected from the respondents using pre-tested questionnaires. Reveal Q+ Kits were used to quantify aflatoxins and fumonisins in sampled meals. Monte Carlo risk simulation using @RiskPalisade software (UK) was used to generate exposure data. All porridge samples had varying detectable levels of mycotoxins. However, there were no significant (P < 0.05) differences in the aflatoxins and fumonisins levels for samples from different EPAs indicating the endemic presence of mycotoxins within the district. Over 95% of the schools used maize as the main ingredient in preparing the porridge with relatively high quantities consumed 610 grams/child/day equivalent to 0.019 kg/kg bodyweight/day regardless of the gender (χ2 = 5.624, P = 0.286) or the age (r = 0.033, P = 0.459) of the respondents. The levels of aflatoxins and fumonisins in the samples ranged from 2.13 to 33.37 µg/kg and < 0.3 to 1.0 ng/kg,  respectively. The mean and the 95th percentile intake levels for aflatoxins ranged from 0.2 - 0.60 ng/kg bodyweight/day and 6 – 9.2 µg/kg bodyweight/day for fumonisins, which exceeded the recommended safety levels for children according to standards of European Food Safety Authority (2007) and Joint Food and Agriculture Organization/World Health Organization Committee on Food Additives (2008), respectively. The consumption of maize-based porridge was found to expose school-going children to unacceptable levels of mycotoxins whose effects on their health, education and well-being remain unknown. There is a need to educate food handlers on mycotoxins intoxication and proper postharvest handling practices of maizebased foods to prevent exposure. Furthermore,  diversification to reduce overreliance on maize-based diets should be promoted. Key words: Aflatoxins, Fumonisins, Exposure, School children, School Meals, Maizebased-porridg

Biopsy case mix and diagnostic yield at a Malawian central hospital

Cancer is a major disease burden worldwide resulting in high morbidity and mortality. It is the leading cause of mortality in developed countries and is one of the three leading causes of death for adults in developing countries. Pathological examination of tissue biopsies with histological confirmation of a correct cancer diagnosis is central to cancer care. Without an accurate and specific pathologic diagnosis, effective treatment cannot be planned or delivered. In addition, there are marked geographical variations in incidence of cancer overall, and of the specific cancers seen. Much of the published literature on cancer incidence in developing countries reflects gross estimates and may not reflect reality. Performing baseline studies to understand these distributions lays the groundwork for further research in this area of cancer epidemiology. Our current study surveys and ranks cancer diagnoses by individual anatomical site at Queen Elizabeth Central Hospital (QECH) which is the largest teaching and referral hospital in Malawi. A retrospective study was conducted reviewing available pathology reports over a period of one full year from January 2010 to December 2010 for biopsies from patients suspected clinically of having cancer. There were 544 biopsies of suspected cancer, taken from 96 anatomical sites. The oesophagus was the most common biopsied site followed by breast, bladder, bone, prostate, bowel, and cervical lymph node. Malignancies were found in biopsies of the oesophagus biopsies (squamous cell carcinoma, 65.1%; adenocarcinoma, 11.6%), breast (57.5%), bladder (squamous cell carcinoma, 53.1%) and stomach (37.6%). Our study demonstrates that the yield of biopsy for clinically suspected malignancy was greater than 50% for the 11 most common sites and provides a current survey of cancer types by site present in the population reporting to our hospital

Exploring assumptions in crop breeding for climate resilience: opportunities and principles for integrating climate model projections

Crop breeding for resilience to changing climates is a key area of investment in African agricultural development, but proactively breeding for uncertain future climates is challenging. In this paper, we characterise efforts to breed new varieties of crops for climate resilience in southern Africa and evaluate the extent to which climate model projections currently inform crop breeding activity. Based on a survey of seed system actors, we find that the prioritisation of crops and traits is only informed to a limited extent by modelled projections. We use an ensemble of CORDEX models for mid and end of century for southern Africa to test some of the assumptions that underpin current breeding activity, particularly associated with breeding for reduced durations and drought tolerance in maize, and demonstrate some of the ways in which such projections can help to inform breeding priorities and agenda setting (e.g. through the case of assessing cassava toxicity risk). Based on these examples, we propose five potential applications of climate models in informing breeding priorities. Furthermore, after unpacking the sources of uncertainty within the presented model projections, we discuss general principles for the appropriate use of climate model information in crop breeding

Manual for sweetpotato pre‐basic seed production using the sandponics system.

This manual explains the procedures involved in setting up the sandponics system and managing it to multiply sweetpotato pre‐basic seed to ensure a dependable supply of high‐quality planting materials

Determination and comparison of vitamin C, calcium and potassium in four selected conventionally and organically grown fruits and vegetables

It is evident that the growing interest in organically grown produce has correspondingly necessitated the debate on the nutritional supremacy between organically and conventionally grown produce. A study was carried out to determine and compare vitamin C, calcium and potassium in organically and conventionally grown cabbage, carrots, Cos lettuce and Valencia oranges. Samples were purchased from local supermarkets within Central Coast, New South Wales in Australia from late March to early April 2007. Vitamin C content was determined by 2,6-dichloroindophenol titrimetric method while calcium and potassium were determined by atomic absorption spectroscopy. Results from the study showed inconsistent pattern with respect to vitamin C, calcium and potassium contents in the conventionally and organically grown samples. No significant differences were observed in vitamin C content in conventionally and organically grown cabbage, carrots and Cos lettuce while significant differences were observed in Valencia oranges which showed higher vitamin C content in organic Valencia oranges as compared to conventional ones (51.8 to 43.4 mg/100 g fresh weight). Results on calcium and potassium contents showed significant differences in all the samples with the trend of higher values for organically grown cabbage, carrots and Cos lettuce as opposed to their conventionally grown counterparts. However, for Valencia oranges, results showed that the calcium and potassium contents were significantly higher in conventional Valencia oranges compared to the organic Valencia orange (54.5 and192.0 mg to 51.8 and 189.5 mg/100 g, respectively)

Exploring Farmers' Knowledge and Approaches for Reducing Post-Harvest Physiological Deterioration of Cassava Roots in Malawi

Cassava utilisation in Malawi is negatively affected by rapid deterioration of fresh roots, primarily caused by postharvest physiological deterioration (PPD). A study was conducted to assess farmers' knowledge and approaches used to minimize losses from PPD. Multi-stage sampling was used to identify districts, Extension Planning Areas (EPA's) and farmers. Data were collected from 519 farmers using a structured questionnaire. Results revealed that PPD (74.0%) was the major post-harvest constraint followed by pests and diseases (62.1%). Farmers had varying knowledge levels on signs and causes of PPD. They were knowledgeable on PPD signs with 91.5% ably identifying PPD through change of pulp colour. The farmers also had moderate knowledge on causes of PPD, citing high temperature (57.6%) and over-staying of roots (56.2%) as main causes of PPD. Key methods for preventing PPD are: storage (43.0%) and piece-meal harvesting (40.4%). Only 2.6% of the farmers exploited varietal difference in dealing with PPD as some varieties (Sauti, Mpuma, Ching'amba, and Kalasa) take three to five days before showing PPD signs. Farmers' knowledge levels and PPD preventive methods could be strengthened through: provision of training on post-harvest handling, improvement in storage and processing technologies; and application of advanced breeding techniques to exploit genetic variation in cassava germplasm