Physical and chemical characteristics of off vine ripened mango (Mangifera indica L.) fruit (Dodo)

The need to develop the best off vine mango ripening technique for both consumption and processing was investigated. Some physical and chemical measurements were performed on mature Green Dodomangoes before and during a 3-day and 6-day ripening period by smoked pit ripening (SPR), ethylene (fruit generated) pit ripening (EPR), untreated pit ripening (UPR) and room temperature ripening (RTR) as a control method. The post harvest ripening changes in the quality characteristic of ripe mangoes were correlated among treatments and compared with similar changes in other mango varieties. Changes such as formation of sugars, decreased acidity, and increased carotene reflected the mostsignificant chemical changes in ripeness stage

Similarities in functional attributes and nutritional effects of magadi soda and bean debris-ash used in cooking African traditional dishes

Magadi soda and bean debris-ash have been used as condiments for a long time by various ethnic groups in East and Central Africa in cooking traditional dishes. The aim of the study was to investigate whether magadi soda and bean debris-ash had similar effects and functional attributes when added to traditional dishes during cooking. Reason for the addition of the two condiments has not been revealed by researchers. Mineral content, in-vitro bioavailability studies and pH of non-ashed and ashed magadi soda and bean debris were evaluated. The results indicated that high concentrations of sodium ions (30.2%) and potassium ions (64.2%) were observed in magadi soda and bean debris-ash, respectively. In-vitro iron and zinc bioavailability decreased significantly with the addition of magadi soda and bean debris-ash in maize, beans and sorghum. Equally, the cooking time was significantly reduced. The mean pH for both magadi soda (9.66) and bean debris-ash (9.75) were not significantly different indicating that both aqueous solutions had alkaline properties. The similarity in properties especially in mineral profile, alkalinity, decreased cooking time and lowered mineral uptake by magadi soda and bean  debris-ash explain similar functionality in foods they are added to during cooking. Despite the similarities  observed, communities should be informed of the negative nutritional effects of these condiments so as to diversify their meal patterns accordingly.Key words: Magadi soda, bean ash, traditional dishes, minerals, in-vitro bioavailabilit

Copper and Lead levels in two popular leafy vegetables grown around Morogoro Municipality, Tanzania

Tanzania Health Research Bulletin, 2006; 8 (1): 37-40A study was carried out to determine the levels of two heavy metals, Lead (Pb) and Copper (Cu), in two popular leafy vegetables grown around Morogoro Municipality in Tanzania. Vegetable samples of Pumpkin leaves (Cucurbita moschata) and Chinese cabbage (Brassica chinensis) were collected from three sites and analysed for their concentrations of the two metals using an Atomic Absorption Spectrophotometer. The three sites, namely Mazimbu, Kihonda and Towelo are located within a 10 km perimeter. The site selection was based on the anticipated levels of contamination of the water used for irrigation. The results showed that the levels (mg/100g dry weight) ranged from 0.885 to1.39 for Copper and 0.05 to 0.315 for Lead. The levels of Lead and Copper varied between the vegetable varieties and from site to site. Vegetables from Mazimbu showed higher concentration levels of the two metals compared to the other sites in both varieties. Towelo vegetables had relatively low concentrations. There was a significant difference (P0.05) in the levels of Copper between the two vegetable varieties from all the three sites. There was a significant difference (P<0.05) in the levels of Lead between the vegetable varieties. The levels of both Lead and Copper in the two vegetables were found to be below the maximum permissible levels recommended by FAO/WHO for the two metals in vegetables

Copper and Lead levels in two popular leafy vegetables grown around Morogoro Municipality, Tanzania

Tanzania Health Research Bulletin, 2006; 8 (1): 37-40A study was carried out to determine the levels of two heavy metals, Lead (Pb) and Copper (Cu), in two popular leafy vegetables grown around Morogoro Municipality in Tanzania. Vegetable samples of Pumpkin leaves (Cucurbita moschata) and Chinese cabbage (Brassica chinensis) were collected from three sites and analysed for their concentrations of the two metals using an Atomic Absorption Spectrophotometer. The three sites, namely Mazimbu, Kihonda and Towelo are located within a 10 km perimeter. The site selection was based on the anticipated levels of contamination of the water used for irrigation. The results showed that the levels (mg/100g dry weight) ranged from 0.885 to1.39 for Copper and 0.05 to 0.315 for Lead. The levels of Lead and Copper varied between the vegetable varieties and from site to site. Vegetables from Mazimbu showed higher concentration levels of the two metals compared to the other sites in both varieties. Towelo vegetables had relatively low concentrations. There was a significant difference (P0.05) in the levels of Copper between the two vegetable varieties from all the three sites. There was a significant difference (P<0.05) in the levels of Lead between the vegetable varieties. The levels of both Lead and Copper in the two vegetables were found to be below the maximum permissible levels recommended by FAO/WHO for the two metals in vegetables

Assessment of harvesting and post-harvest handling practices on organically grown cloves and black pepper in Tawa Ward, Morogoro

Post-harvest management of spices is crucial in minimizing losses and upholding quality and safety along the value chain. This study assessed harvesting and post-harvest handling practices of clove and black pepper organically grown in Tawa Ward, Morogoro; to establish the quality compromising stages. A total of 107 clove and black pepper farmers were interviewed using a semi-structured questionnaire to assess harvesting, drying and storage practices. Thirty-four spice samples from 34-randomly selected farmers were collected in airtight bags for moisture content determination. Data were statistically analyzed using IBM SPSS Statistics, version 20. Farmers in this study practice mixed farming, and handpicking harvesting to manageable amounts of spices (&lt;100 kg/year). Spice drying is done on the ground by 80% of the farmers. Poor storage methods, mixing spice batches and attempts to treat spoiled spices were noticed as critical points that could compromise final quality. More than 46% of black pepper farmers acknowledged post-storage treatment of spoiled and contaminated spices including rubbing spices with cooking-oil and blanching. Such treatments along with higher moisture contents were related to farmers’ unawareness on post-harvest management. Moisture content of the final dried spices ranged from 23.9-14.8 (clove) and 13.8-10.1 (black pepper) indicating that farmers are struggling to achieve the recommended moisture content of 12% as per TZS 357:2012 and TZS 30:2013. This study calls for interventions of improving farmer’s knowledge and making use of simple but effective methods; like drying of spices on raised platforms and use moisture meter to determine the final level of dryness

Effect of germination and autoclaving of sprouted finger millet and kidney beans on cyanide content

Tanzania Journal of Health Research, 2010; 12 (4)Cyanide contents of locally purchased brown finger millet (Eleusine corocana L. Gaertner) and brown speckled kidney bean seeds (Phaseolus vulgaries var. Rose Coco) were determined using raw, germinated and autoclaved samples. The aim was to establish the extent of cyanide content increase resulting from the germination process and the effectiveness of the autoclaving process on the reduction of cyanide levels in the samples, for safety considerations. Autoclaving was carried out at 121°C for 20 minutes. It was found that germination increased the cyanide content by 2.11 to 2.14 fold in finger millet for laboratory processed samples. In the case of kidney beans the increment was 1.76 to 1.77 fold for laboratory samples. The increments for field processed samples were in the same range as those for laboratory samples. Autoclaving reduced the cyanide content to between 61.8 and 65.9 % of the original raw contents for finger millet and between 56.6 to 57.8% in the case of kidney beans. The corresponding reductions for field samples were also found to be within the same ranges as the laboratory processed samples. It was concluded that autoclaving significantly reduced the cyanide levels in germinated finger millet and kidney beans

Understanding postharvest practices, knowledge, and actual mycotoxin levels in maize in three agro-ecological zones in Tanzania

Maize is a major cereal crop in Tanzania and it is grown in diverse agro-ecological zones. Like other sub-Saharan countries, postharvest losses of maize during storage in Tanzania remain significantly high, especially for smallholder farmers. Unpredictable weather and poor postharvest practice contribute to rapid deterioration of grain and mold contamination, and subsequent production of mycotoxins. The purpose of this study was to assess awareness and knowledge regarding mycotoxin contamination in maize grain in three agro-ecological zones (Eastern, Central, and Northern) of Tanzania between November 2015 and February 2016. A survey using questionnaires was administered to farmers, traders, and consumers of maize. A total of 90 people (30 from each zone) were surveyed with a response rate of was 96% (87/90). In addition, several samples of maize were collected and analyzed for aflatoxin, fumonisin, and zearalenone contamination to validate the awareness and knowledge of mycotoxin contamination of maize. The result shows a high level of postharvest losses of maize mainly through insect infestation. Moreover, over 80% of the farmers, traders, and consumers of maize were unaware of mycotoxins contamination. All maize samples collected contained detected levels of mycotoxins. The maximum concentration of aflatoxins, fumonisin, and zearalenone in maize samples was 19.20 ppb,, 7.60 ppm, and 189.90 ppb respectively. Education intervention is necessary to decrease the disconnect observed between actual mycotoxin contamination and the awareness and knowledge of farmers, traders, and consumers of maize in Tanzania. Enhancing awareness and knowledge provide the opportunity to educate on post-harvest practices that reduce postharvest losses and mycotoxin of maize in Tanzania.This article is from the Journal of Stored Products and Postharvest Research, 8, no. 7 (2017), doi:10.5897/JSPPR2017.0243. Posted with permission.</p

Physio-chemical, mineral composition and antioxidant properties of roselle (hibiscus sabdariffa l.) Extract blended with tropical fruit juice

African journal of food, agriculture, nutrition and development, 2014; 14 (3): 8963-8978.Different varieties of fruit juices and beverages are available globally and there has been an increased consumption of fruit juices and beverages due to consumer awareness of nutritional and health benefits. Juice extracts are produced from various parts of plants including leaves, fruits and flowers. Hibiscus sabdiriffa (Roselle) is one such plant whose flowers are used to prepare juices. The roselle extract has a unique red colour, good flavour, low sugar and high acidic content. The acidity makes the juice sour hence the need for addition of sweetening products. A study was conducted on the formulation of roselle extract-tropical fruit blends aimed at establishing its physiochemical, mineral and antioxidant composition. Dried roselle calyces at a ratio of 1:10 (dried roselle calyces: water) were extracted at 50oC for 30 minutes. The roselle extracts were blended at various proportions of fruit (mango, papaya and guava) juices. Physiochemical, mineral composition and antioxidant properties were evaluated in all the roselle fruit juice blends The results for all rosellefruit blends (80% roselle to 20% roselle) showed that pH ranged between (2.35-3.32), total soluble solids (5.6-10.6o Brix), titratable acidity (1.28-1.92 %), reducing sugars (2.95-5.55) mg/100g,. Calcium (555.3-23.4 mg/100g DM), Magnesium (213.8-11.5 mg/100g DM), Phosphorus (39.8-9.0 mg/100g DM), Sodium (2.3-5.47 mg/100g DM), Zinc (5.85-0.69 mg/100g DM), Iron (29.5-1.36 mg/100g DM), monomeric anthocyanin (493.5-118.2 mg cyanidin-3-glucoside/100g), vitamin C (40.0-86.5 mg/100g), total phenol (54.6-10.8 mg gallic acid/ 100 g) and antioxidant activity (1.80-1.37 mmol/L). Blending of tropical fruit juices with roselle extract have improved mineral composition and antioxidant properties of fruit juices as roselle is a good source of calcium, magnesium and iron. Antioxidants acts as free radical scavengers inhibit lipid peroxidation and other free radical mediated process, therefore, consumption of roselle-fruit juices with high anthocyanin will protect human body from several diseases attributed to the reactions of free radicals