Department of Food Science and Agro-processing

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Acceptability of soup powders made from selected traditional leafy vegetables grown in Lindi, Tanzania
(2021) Abdallah, A.; Chove, L. M.
A study was conducted to assess the acceptability of soup formulated from traditional leafy vegetables (TLVs) grown in Lindi, Tanzania. Three TLVs, Amaranth hybrids known as amaranthus leaves (AML), Manihortesculenta known as cassava leaves (CAL) and Ipomeabatatas known as sweet potatoes leaves (SPL) which had been optimized for Iron content, were used to prepare 4 vegetable soup formulations (F1– 60.0:7.5:22.5); (F2 –70.0:5.0:15.0); (F3 –80.0:2.5:7.5) and (F4 –40.0:10.0:40.0) respectively. Descriptive sensory analysis was performed by10 trained panelists who used 5 descriptors to quantitatively describe the sensory characteristics of four soup formulations. Thirty consumers assessed the degree of liking of products’ sensory attributes using a 7-point hedonic scale. External preference mapping was performed by relating sensory data with hedonic responses. Mean intensity ratings of descriptive attributes of the soup showed that F1, F2 and F3had significantly higher(p<0.05) mean intensity scores in colour, aroma, and mouth feel than F4. The consumer study showed that, with exception of mouth feel, consumers showed significant differences (p<0.05) between samples in colour, aroma, taste and overall acceptability. It was thus concluded thatF1 was the most liked by consumers due to colour, aroma and mouth feel followed by F2 and then F3 and finally F4. Furthermore, the preference mapping results showed that colour, aroma and mouth feel attributes were the main drivers for positive consumer preference for vegetable soup. Thus, selection and processing of vegetables, which retain these attributes, is of greater importance for consumer acceptability and hence increased utilization for consumer’s health and well-being.
Application of slightly acidic electrolyzed water as a potential sanitizer in the food industry
(Hindawi, 2024-02-29) Issa-Zacharia,Abdulsudi
Te food industry has extensively explored postharvest microbial control, seeking viable technologies to ensure food safety. Although numerous chlorine-based commercial sanitizers serve this purpose, many are plagued by constraints such as instability and diminished disinfectant efcacy. Tese issues arise from exposure to organic matter in wash water, light, or air. As an innovative and promising alternative, slightly acidic electrolyzed water (SAEW) has emerged, captivating attention for its robust sterilization potential and eco-friendliness in agricultural and food sectors. SAEW generated via electrolysis of a diluted hydrochloric acid (HCl) solution with concentrations ranging from 2 to 6% or aqueous solution of sodium chloride (NaCl) in a nonmembrane electrolytic chamber is reported to possess equivalent antimicrobial properties as strong acidic electrolyzed water (StAEW). In contrast to traditional chlorine sanitizers, SAEW leaves less chlorine residue on sanitized foods such fresh-cut fruit and vegetables, meat, poultry, and aquatic products due to its low available chlorine concentration (ACC). Its near neutral pH of 5 to 6.5 not only renders it environmentally benign but also mitigates the production of chlorine gas, a contrast to low pH conditions seen in StAEW generation. Te bactericidal efect of SAEW against various strains of foodborne pathogens is widely believed and accepted to be due to the combined action of high oxidation-reduction-potential (ORP) reactions and undissociated hypochlorite/ hypochlorous acid (HOCl). Consequently, a burgeoning interest surrounds the potential of SAEW for sanitation in the food industry, ofering an alternative to address shortcomings in sodium hypochlorite solutions and even StAEW. It has been hy- pothesized from a number of studies that SAEW treatment can increase the quality and nutritional value of harvested fruits, which in turn may enhance their ability to be stored. Terefore, SAEW is not only a promising sanitizer in the food industry but also has the potential to be an efcient strategy for encouraging the accumulation of bioactive chemicals in plants, especially if it is used extensively. Tis review encapsulates the latest insights concerning SAEW, encompassing its antimicrobial efectiveness, san- itization mechanism, advantages vis-à-vis other sanitizers, and plausible applications across the food industry
Assessment of bacterial contamination and associated risk factors in pork slaughtered and marketed in urban Tanzania
(Tanzania Journal of Health Research, 2023-10) Nonga Cosmas; Zacharia Issa; Mkupasi Ernatus; Ngowi Helena
Introduction: In Tanzania, pork consumption is increasing and become popular in urban areas creating a good market for pigs raised in rural areas. However, little is known regarding the microbial safety of the marketed pork in the country. This study assessed the level of bacterial contamination and contributing factors in pork slaughtered and sold in Arusha, Dar es Salaam and Dodoma Tanzania through Total Viable count, Coliform count, Escherichia coli and Staphylococcus aureus count. Methods: A cross-section study was conducted and a total of 90 pork samples were collected from pig slaughter facilities, pork centres and butcheries. Standard methods for microbial analysis in food products (ISO 7218:2007(E)) were used. Results: It was revealed that all (100%) pork samples had bacteria contamination with an overall mean for total viable count of 5.93±1.50 log CFU/g, and coliform forming unit of 4.30±1.14 log CFU/g. Over 92.2% of the pork samples were contaminated by E.coli with a mean count of 3.12±1.33 and S. aureus was isolated in more than 84.4% with a mean count of 2.71±1.34 log CFU/g. The mean values were higher than the limit set by Tanzania Standard (TBS/AFDC 22 (5266) P3). In addition, 79.4% of the pork slaughter facilities and selling points surveyed had poor hygiene and lacked safety and quality control measures. Conclusion: Thus, it may be deduced that the pork carcasses assessed were of poor microbiological quality posing a health risk to pork consumers. To minimize public health risks, food control authorities should ensure effective enforcement of policies and regulations in controlling pig slaughtering and pork marketing in the country. Also, education on hygienic practices for all stakeholders along the pork value chain should be provided.
Assessment of compliance with good agricultural practices in pig farming in Mpwapwa and Mbulu districts, Tanzania
(Taylor & Francis Group, 2023-07-14) Nonga, Cosmas; Zacharia, Issa; Mkupasi, Ernatus; Ngowi, Helena
A cross-sectional study was conducted between February and May 2022 to explore the pig farming practices and assess their compliance with Good Agricultural Practices (GAPs) and their associated constraints in Mpwapwa and Mbulu districts. A total of 136 pig farmers were randomly chosen from purposively selected wards for interview using a structured questionnaire. The study revealed that 71.3% of all pig farmers were aware of GAPs on pig farming, but only 19.8% of the pig farmers complied with the stipulated GAPs. About 81.6% of the respondents had poor piggery hygiene and 76.5% had poor piggery conditions. Pig farmers reported the cost of feeds (83.8%) and veterinary services (81.6%) to be the hindrance to compliance with GAPs. It was concluded that pig farmers are aware of GAPs but not all implement them. Limited availability and high costs of pig feeds and veterinary services are among the factors limiting the full implemantation of GAP in pig farming in the Mpwapwa and Mbulu districts. Therefore, there is a need for the Ministry of Livestock and Fisheries Development and private investors to collaborate to ensure accessibility to Agro-vet services in rural areas with minimal cost. A positive effect could also result from encouraging pig farmers to use locally available ingredients to compose pig feeds.
Assessment of indoor storage technology on white colour sweet potato tubers (Ipomoea batatas L.Lam) in Morogoro, Tanzania
(Sokoine University of Agriculture, 2024-04) Kimako, Joseph R.
Sweet potato (Ipomoea batatas L.Lam.) is a dicotyledonous plant grown as a tuber crop. Sweet potatoes originated from tropical America (Coop, 2010). Sweet potatoes are widely cultivated mainly around the lake zone, eastern zones, southern highlands, and northern parts of Tanzania (URT, 2016). It is grown by 771,257 households during short rainy and long rainy seasons, with an estimated annual production of 504,346 tonnes (NBS 2012). Sweet potato tubers contribute to food security and income generation (Ahmad et al., 2014). Sweet potatoes' high perishability after harvesting is one of the major factors limiting their potential. Insufficient information concerning efficient storage technology limits farmers and traders from choosing the best technology to reduce losses. The research by Teye et al. (2011) compared two storage technologies: the Purpose-Built Evaporative Cooling Barn and Modified Pit Storage under Ghana conditions, neglecting other sweet potato storage technologies. Further research by Mpagalile et al. (2007) used the traditional pit, improved open pit, improved housed pit (mjinge) and raised woven structure (Kihenge) to evaluate the storability of sweet potato under Tanzania conditions neglecting other sweet potato storage technologies. Purpose Evaporative Cooling Barn and housed pit storage are still techniques used to attain optimum temperature and relative humidity for sweet potato storage with temperatures between 12.5°C and 15°C and relative humidity from 85% to 90%. Nevertheless, their adaptability to small-scale farmers and traders in developing countries like Tanzania is limited due to their high initial capital and high running costs for White-coloured sweet potato tubers. Small-scale farmers and traders are in high demand for storage technology, which is low in capital and running costs. Indoor storage technologies are a better choice as they maintain proper storage temperature and relative humidity through ventilation and are used in hot and arid areas (Baimey et al., 2017). In this technology, White coloured sweet potato tubers can be stored with minimum changes in colour, weight, rotting and firmness (Gopala, 2015).This study aimed to assess indoor storage technology on white colour sweet potato tubers (ipomoea batatas l.lam) in Morogoro, Tanzania, that will help to minimise losses of white sweet potato tubers. According to the findings, the most significant cause of post-harvest losses was rodent attack, which was reported by 26.53% and 25% of farmers and traders in Gairo and Morogoro municipalities, respectively, and the extent of white-coloured sweet potato tuber losses observed was 18.36% of farmers and traders in Gairo and 79% of farmers and traders in Morogoro municipality have reported to suffer from moderate post-harvest losses. White-coloured sweet potato tubers stored in ventilated bags and the improved traditional raised platform resulted in a weight loss of 49.4% and 68.7%, respectively. It was also observed that the improved traditional raised platform had a significantly high total soluble content /concentration, with a value of 21.27%. In comparison, Ventilated bags resulted in a Total soluble solid content of 17.02 %, which was significantly low. Furthermore, results show that Ventilated bags had the lowest beta carotene content (8.72 μg/g) compared to other treatments. Results indicate that traders’ source of funding for their sweet potato selling activity was own/self-financing, estimated at 70%, loans estimated at 19.37%, and remittances estimated at 10.63%. Also, the study's findings demonstrate that the single and multi-stage channel systems are the two main sweet potato marketing channels. Retailers constitute 57.5% of respondents, wholesalers 27.5%, and other trades (Middlemen/SME processors) 15%. Furthermore, a study indicated that 21% of traders produce sweet potatoes on their farms, and 97% of merchants purchase sweet potatoes directly from farmers also, 42% purchase sweet potatoes through wholesalers/aggregators. Results continued to reveal that by using ventilated bags storage technology, farmers and traders could earn higher profits, which was Tsh 19,000/= more than other storage technologies (improved traditional raised bamboo buckets and woven Polypropylene Bags.The study results indicate a need to improve post-harvest loss awareness among white-coloured sweet potato farmers and traders to reduce loss and thus begin producing profitably. Also, controlling rodents, avoiding injury, building a proper storage facility and inspecting the stores regularly are the most important aspects to consider when preventing losses. Also, findings suggest that storing white-coloured sweet potato tubers in ventilated bags is appropriate. Using ventilated bags can also be effective when storing undamaged sweet potato tubers. Farmers and traders are advised to sort and grade their tubers before storage. Furthermore, additional research studies should be conducted to develop awareness of other types of storage and methods for reducing sweet potato losses to impact food security in society.
Assessment of knowledge, attitudes and practices on breastfeeding among HIV infected mothers with infants in Kibaha town council
(Sokoine University of Agriculture, 2011) RWERAMIRA,MARGARETH CLEMENT
Knowledge, Attitudes and Practices (KAP) on breastfeeding among HIV-infected mothers are important in determining the health and nutritional status of their children. The HIV pandemic and the risk of mother-to-child transmission (MTCT) of HIV, especially through breastfeeding (BF) poses special difficulties to HIV-infected mothers, their infants and the community. This study was designed to assess KAP on breastfeeding among HIV-infected mothers having children aged 0-12 months living in Kibaha Town Council. A cross-sectional, descriptive study design was employed and convenient sampling procedure was used to select the respondents. Primary data were collected using structured questionnaire which were administered by face to face interview. Data analysis was done using Statistical Package for the Social Science (SPSS) 15.0 version computer software. The study findings revealed that there is limitation in terms of KAP on BF, complementation and infant feeding options among the HIV-infected mothers. Breastfeeding was chosen by majority of respondents (96%) compared to replacement feeding (6%). About 76% of mothers ceased to practice EBF before their infants were six months old due to fear of MTCT of HIV. The study also revealed that mothers’ level of education was significantly associated with their knowledge (p = 0.00403). Mixed feeding (63.6%) and nipple cracks (77.8%) were the most known factors by the respondents to increase the risk of MTCT of HIV. Breast conditions such as sore/cracked nipples; fear of stigma; lack of counselling and follow up from the health workers; and cultural beliefs such as BF by using one breast were observed as the constraints faced by the respondents. Counselling services on infant feeding options, regular follow to mothers and more training to the counsellors on BF and PMTCT of HIV need to be strengthened
Attitude towards learning food and nutrition subject and eating behaviours of ordinary level secondary school students in Dodoma region.
(Sokoine University of Agriculture, 2022) Songo, Vashty Nyabhigeso
The learning outcome of food and nutrition subject depends on attitude of the leaners towards the subject. In Tanzania, food and nutrition subject is taught in selected secondary schools at the ordinary level education and in even fewer schools at the advanced level. This study aimed to determine whether the attitudes towards learning food and nutrition subject influence eating behaviours of secondary school students. Data were collected in Dodoma region from three purposively selected secondary schools. The study involved 381 students who were randomly selected whereby 194 students opted and 187 did not opt to study food and nutrition subject. Nutrition information in the syllabus, teaching and learning materials were collected through documentary desk review. Students' attitudes towards studying food and nutrition subject and their eating behaviours were assessed through structured questionnaires that included, the dietary diversity component among others. Statistical Package for the Social Sciences (SPSS) Version 20 software was used to analyze descriptive and inferential statistics where t-test was conducted while qualitative data were analyzed by the text analytics program and interpreted according to the emerging themes. The study observed that syllabus had objectives that were relevant to the nutritional needs of the country. The subject specific textbooks were absent instead there were eleven (11) reference books used in all the surveyed schools. Those reference books had outdated nutrition information hence, not satisfactory to fulfil the need of the current syllabus and on address the existing problem of triple burden of malnutrition. Gender was found to influence choosing of the subject since mean attitude scores for males (M = 2.0154) which was half to that of females (M = 4.4995). Opting to study the subject influences eating behaviour significantly (p-value < 0.01). Among the 194 students who opted to study food and nutrition subject, 93% had proper eating behaviour because number of food groups eaten per day was five and above hence their dietary diversity score was above five (5). The students who had improper eating behaviour due to the fact that their diet consist less than five food groups was 7% hence their dietary diversity score was below five. The study concluded that students practice what was taught to improve their eating behaviour because students who opted for Food and Nutrition Subject had adequate dietary diversity in their diet compared to those who did not opt for studying the subject. The study recommends that, subject extracurricular activities on nutrition programs should be given to all students in order to emphasis and provide opportunity of improving their eating behaviour for their lifelong future benefits.
Awareness of aflatoxin contamination and safety of maize along supply chain in Kondoa and Chemba districts in Dodoma, Tanzania
(Sokoine University of Agriculture, 2022) Ndwata, Asha Hamad
Maize (Zea mays) is a staple food for the majority of people in Tanzania, which plays a key role in subsistence and as a cash crop among actors of the maize value chain. The study was conducted during the 2020–2021 cropping season in two districts, Kondoa and Chemba, in the Dodoma region of central Tanzania. The objectives were to assess stakeholders' awareness of aflatoxin contamination in maize (smallholder farmers, traders, and consumers), to assess post-harvest handling practices of maize among smallholder farmers, and to determine the current levels of aflatoxins B 1 contamination in maize. Structured questionnaires were used to collect the data. A cross-sectional survey was used in collecting primary data. A total of 380 respondents, including smallholder farmers, traders, and consumers from each ward, were selected. In addition, 90 maize samples (40 from smallholder farmers, 20 from traders, and 30 from consumers) were analyzed for aflatoxins using High-Performance Liquid Chromatography (HPLC). The results show about 56% of the smallholder farmers and 52% of the traders were aware of the contamination. However, the majority of the main stakeholder (consumer) was unaware of the contamination with aflatoxins (74%). Moreover, the result shows smallholder farmers had inadequate knowledge of best post-harvest practices and these were associated with post-harvest losses and the microbiological quality of maize. It was observed that the majority of smallholder farmers (75% ) used traditional post-harvest handling practices such as harvesting maize and placing it on the ground, storing maize in galleries, drying (on the ground); use of polypropylene bags as a storage facility. Few samples of the maize value chain were contaminated with AFB 1 and total aflatoxins. Furthermore, the result shows five-point six percent (5.6%) of collected samples were contaminated with aflatoxins B 1 , and 3.3% of the aflatoxins samples exceeded the European Union (EU) and Tanzania Bureau of Standards (TBS) regulatory limits for AFB 1 and were mainly collected from traders in Kondoa district. Extension workers should train farmers on effective post-harvest management practices of maize in order to minimize losses and improve the quality. In addition, efforts should be made to educate the general public, particularly consumers, about the dangers of aflatoxins contamination, and affordable techniques should be made available to maize farmers in the Kondoa and Chemba districts of Dodoma, Tanzania, in order to reduce grain losses and increase income and food security.
Bushmeat consumption in Africa: a microbiological safety challenge?
(Asian Food Science Journal, 2023-09-12) Ahouanse Gwladys Gloria Amen; Issa-Zacharia Abdulsudi; Majaliwa Nuria
Objective: This review analyzed the microbiological safety of bushmeat consumed in Africa over the past decades. Methodology: Previous Studies mainly focused on large animals like antelopes and smaller ones like grasscutter. Most microbes studied were similar to those in domestic animal meat, except for rare pathogens such as Salmonella spp, E.coli. Sampling, experiments, and microbe prevalence varied among studies. Results: All studies confirmed the presence of zoonotic pathogens dangerous to human beings. Therefore, more investigations are needed, especially for the chronic and severe cases of pathogens, since only few studies have addressed the bushmeat's microbiological safety in Africa. Conclusion: Efforts should be made to improve bushmeat safety and public health in Africa. New policies and public regulations must be developed and implemented to ensure hygienic and legal bushmeat production in Africa.
Chemical quality of stream and borehole water used by selected communities in Lushoto district, Tanzania
(An International Journal of Basic and Applied Research, 2020) Hadija, A.; Chove, L.
The chemical quality of water in two streams and three boreholes from Sunga and Mbaru wards in Lushoto, Tanzania was investigated. Water was collected at three locations along the stream, including forest areas, populated area with agricultural activities and less populated areas with agricultural activities. Borehole’s water was collected from three boreholes found in each ward and analyzed for pH, hardness, BOD, phosphates, nitrates by standard methods. Nested design was applied. Data obtained was analyzed by R-Software for ANOVA. Means were separated by Tukey‘s honest at p<0.05. Significant differences (p<0.05) in all chemical parameters (pH: 6.92- 7.34; Hardness; 23.88+64.43;Nitrite 1.73 -19.80; Phosphate 0.58-3.90; Ammonia 0.02-0.08; Lead -0.001-0.002) were observed in locations within the streams except arsenic. DDT was not detected. With the exception of phosphate in both streams, all water samples tested met TZS (2016) standards and WHO (2011) guidelines. This implies that stream water is considered unsafe for use since it exceeded the maximum phosphate limit by TZS (2016). All parameters tested in borehole water met the requirements for both standards except pH and ammonia which exceeded the WHO water guideline. It is recommended that the communities be educated on the best practices to keep water sources safe.
Colour and antioxidant activities of honey from different floral sources and geographical origins in Tanzania
(Tanzania Journal of Agricultural Sciences, 2016) Shekilango, S. G; Mongi, R. J; Shayo, N. B
Honey is a sweet, yellowish liquid that is produced by honey bees and it has been used for many years for nutrition and therapeutic purposes. Its therapeutic potential has been associated to its antioxidant capacity which plays an important protective role in human health through scavenging of free radicals in the human body and thereby decreases the amount of free radical and damage to biological molecules like lipids and DNA. This study was carried out to investigate the effect of floral source (miombo and acacia) and geographical origin (Central, Coastal, Lake, Northern, and Southern Highland) in mainland Tanzania on colour and antioxidant activity of honey samples. Colour, total flavonoids content (TFC), total phenol phenolic contents (TPC) and antioxidant activities of the samples were evaluated using UV/Vis spectrophotometer, Folin-Ciocalteu reagent and Ferric Reducing Antioxidant Power (FRAP) methods respectively. There were significant (p<0.05) differences in all parameters assessed between floral sources. Miombo honey samples had higher pfund values (mm) for colour ranged from 31.55 mm (white) to 143.98 (dark amber) than acacia samples with values ranged from 17.33 (extra white) to 62.28 mm (light amber). Miombo samples had higher TFC values of 13.5±0.25-39.9±0.42 mgRE/100g DM) and TPC of 127.9±2.5-395.2 mg GAE/100g DM) than acacia samples with values of 12.7±0.60-17.5±0.38 mgRE/100g DM and 119.5-168.2 mg GAE/100g DM respectively. Similarly, significantly (p<0.05) highest and lowest FRAP values of 488.9-956.3 and 252.6-368.26 μM Fe2+/100g DM were observed in Miombo and acacia honey samples respectively. Moreover, variations in colour, TFC, TPC and FRAP between zones were significant (p<0.05). Within the miombo samples, northern and coastal zones had respective lowest and highest values whereas central and northern zones had respective lowest and highest values within the acacia samples. A strong correlation (R2= 0.942) between TPC and antioxidant activities of honey samples suggest that the antioxidant of honey is highly linked to TPC. Therefore, the study has revealed that, floral sources and geographical origins have varied significant effects on colour, flavonoids, total phenols and antioxidant activities of Mainland Tanzania honey. Honey samples from miombo floral source had higher antioxidant activities and hence their consumption is more recommended.
Compliance by SMEs to existing Tanzania standards with respect escherichia coli and staphylococcus aureus in cultured milk: a case of Dar es salaam, Tanzania
(An International Journal of Basic and Applied Research, 2021) Samwel, J.; Chove, L. M.
Small and medium enterprises are important for economic growth not only in Tanzania but all over the world. Most of them are informal, without official registration. However, they provide tremendous contribution to food security, nutrition, income generation and poverty reduction in the country. Therefore, upgrading and modernization of Small and Medium Enterprises (SMEs) to ensure food security, safety and quality of food has becomes one of the priorities of Tanzania development visions of 2025, which is the blueprint of structural economic transformation of the country. To help achieve this, the present study was conducted to assess the safety of cultured milk. A total of 33 cultured milk samples were collected from 11 SMEs which were analyzed in triplicate to make 99. Two microorganisms, Escherichia coli and Staphylococcus aureus were analysed in cultured milk. Results were compared against the existing Tanzania standards. The isolates had an overall mean of 2.02 × 102 ± 1.73 × 102CFU/g, 1.91×102 ± 1.85 ×102CFU/g respectively for E. coli and S. aureusc count. The results obtained were higher than the limits set by the Tanzanian Standard (TZS1625:2013). It may thus be concluded that sampled cultured milk was of poor microbial quality and hence not safe for consumption. Poor hygienic practices during milk handling pose a high risk to cultured milk and render it unsafe for human consumption.
Detection of proteolysis in high temperatures treated milk by reverse phase high performance liquid chromatography (RP-HPLC)
(Academic Journals, 2014-02) Chove Lucy M.; Grandison S. Alistair; Lewis Michael J.; Issa- Zacharia Abdulsudi
Proteolysis of UHT milk during storage is one of the problems affecting the dairy industry worldwide. Native enzymes have been implicated as being the main cause of spoilage of such milk. In the current study, reverse phase high pressure chromatography (RP-HPLC) method was used to detect proteolysis by native enzymes in high temperature heated milk. The aim of this research was to assess susceptibility of milk to proteolysis by native enzymes, after being subjected to various temperature- time processing conditions. Samples of raw and heated milk were clarified prior to analysis. Clarification was carried out to obtain pH 4.6 and 6% TCA soluble extracts, which were injected into RP- HPLC after filtration. This method confirmed that raw milk and milk processed at 85°C /15 s were the most proteolysed, indicating that the high temperatures employed during this study (110, 120, 130 and 142°C for 2s) inactivated the native enzymes. The RP-HPLC method is a useful method for the detection of proteolysis in milk.
Detection of proteolysis in milk by four selected methods
(The University of Reading, 2009) Chove, Lucy Mlipano
Sensitive methods that are currently used to monitor proteolysis are limited due to their high cost and lack of standardisation for quality assurance in the various dairy laboratories. In this study, four methods, trinitrobenzene sulphonic acid (TNBS), reverse phase high pressure liquid chromatography (RP-HPLC), gel electrophoresis and fluorescamine, were selected to determine their suitability for the detection of proteolysis in milk by added trypsin, plasmin, Pseudomonas fluorescens NCIMB 701274 (414) and Pseudomonas fluorescens NCIMB 702085 (416) and Bacillus licheniformis enzymes. Raw, pasteurised and UHT milk used to study proteolysis were analysed by the four methods. Pseudomonas fluorescens enzyme was extracted in this study since commercial enzymes are not available. All four methods confirmed that Pseudomonas fluorescens 416 was more proteolytic than Pseudomonas fluorescens 414. Dialysis was effective in the purification of Pseudomonas fluorescens (Ps. fl.) enzymes increasing the detection limit for the fluorescamine method, which had a low upper detection limit. Prominent peaks by RP-HPLC were shown to occur between 20-30 min for Pseudomonas fluorescens but 20-25 min for Bacillus licheniformis. RP-HPLC confirmed a peptide peak at 35 min in pH 4.6 soluble extract, which was absent in 6% TCA soluble extract, was from plasmin. Casein breakdown profiles by gel electrophoresis confirmed preference for 0-casein degradation over a and K-caseins by both Ps. fl. and B. licheniformis. Comparison of raw and pasteurised milk (72, 85 and 90°C for 15 s) revealed that pasteurisation was insufficient to inactivate plasmin inhibitors. The pH 4.6 and 6% TCA soluble extracts of UHT skim milk with added trypsin or plasmin showed high correlations (R2 > 0.93) by the TNBS, fluorescamine and RP-HPLC methods, confirming increased proteolysis during storage. Gel electrophoresis showed that breakdown products from trypsin were similar to plasmin although the former caused more extensive proteolysis than the latter due to higher enzyme activity, y-caseins, formed as a result of P-casein degradation disappeared (1484 and 742 BAEE units of added trypsin on days 3 and 7) due to extensive proteolysis. This finding had not previously been reported. Milk processed at high temperatures (110, 120, 130 and 142°C for 2 s) had lower proteolytic activities than raw milk and milk heated at 85°C implying inactivation of plasmin at temperatures of 110°C and above. This was observed in all the methods assessed. The TNBS method was recommended on the basis of its accuracy, reliability, simplicity and cost.
Detection of proteolysis in milk by pseudomonas fluorescens using urea PAGE method
(Macrothink Institute, 2017-12-28) Chove, Lucy Mlipano; Alistair, Grandison; Michael, Lewis
Proteolysis of milk during storage by two strains of Pseudomonas NCIMB 702085 (414) and NCIMB 701274 (416) was investigated using the Urea PAGE method. Pseudomonas fluorescens enzymes were also extracted and purified by dialysis before inoculation into UHT skim milk in an attempt to partially purify the enzyme. Results showed that dialysis removed some peptides and amino acids which would interfere with the assay procedure. The method also confirmed that Pseudomonas fluorescens NCIMB 701274 (416) was more proteolytic than Pseudomonas NCIMB 702085 (414). Thus, Urea PAGE is a useful method for monitoring proteolysis in milk by Pseudomonas fluorescens.
Development and sensory evaluation of yoghurt flavoured with solar dried fruits
(Pearl Research Journals, 2017) Ndabikunze, B. K.; Mumba, F. G.; Ngowi, H.; Chove, L; Mongi, R; Abdulsud, I.
A study of developing solar dried fruit (5%) flavoured yoghurts using three types of fruits was conducted to determine acceptability and shelf life of developed products. A total of six samples namely banana, mango, pineapple, banana/mango, banana/pineapple and mango/pineapple were used as flavours in yoghurts. They were added either as fruit pieces or as powders. Shelf life projection study suggested that developed yoghurt products could be stored for up to 21 days at 4 °C without undergoing spoilage. Plain yoghourt (control) was the most liked sample and scored highest mean values for all attributes, which was significantly different from all other samples (p<0.05). Among the fruit flavoured yoghourts, mango was the most preferred sample in terms of flavor, aroma and general acceptability whereas the pineapple was the least acceptable. Although yoghurts flavoured with fruits pieces scored higher mean values in all sensory attributes than yoghurts flavoured with powdered fruits, no significant differences (p>0.05) between the two forms of fruit flavours was found. This needs to be further investigated. Thus, although the control was the most liked sample, solar dried fruit can be successfully used as yoghurt flavour, which may improve the texture and nutritional quality of the formulated yoghurts, making them available throughout the year, hence increasing farmer’s income.
Development of natural liquid and powdered meat tenderizer based on papaya peel, ginger and garlic
(Science Publishing Group, 2024-04-12) Issa-Zacharia Abdulsudi; Muhimbula Happiness Samuel; Bikuba Anastazia Niyonkulu; Mato Joachim Dotto
Recently, the application of exogenous enzymes for meat tenderization has turned the attention of food technologists and meat scientists. This research investigates the synergistic impact of natural tenderizers derived from the combination of papaya peels (P), ginger (G), and garlic (Ga) on the sensory attributes of goat meat such as color, aroma, taste, tenderness and overall acceptability. The tenderizers were formulated in different concentration ratios of 3:2:1 in both liquid and powdered form. The sensory quality parameters for all tenderized goat meat samples under observation including the control, were evaluated by 60 semi-trained panelists using a five-point hedonic scale. The effect of tenderizers was compared to the control which was devoid of tenderizing ingredients. Tenderness was greatly improved (p<0.05) by tenderizer P:G:Ga (3:2:1) in both liquid and powder forms at 45- and 90- minutes of tenderization. Alternatively, liquid and powdered Ga:G:P (3:2:1) were highly significantly rated (p<0.05) in taste compared to all other tenderizer formulations for 45- and 90-minute tenderization. From the samples tested, the control sample in both setups was the least rated in all sensory attributes, except for color in powdered tenderization. Generally, liquid and powdered P:G:Ga (3:2:1) and Ga:P:G (3:2:1) tenderizers received significantly higher (p<0.05) overall acceptability scores than G:G:aP (3:2:1) and the control sample. While liquid tenderizers mostly performed better compared to powdered tenderizers for all sample combinations, there was a significant improvement (p<0.05) in tenderness when both liquid and powdered tenderizers were used for 90 minutes compared to 45-minute marination. This suggests that, the longer the tenderization time, the greater the effect on tenderness. These findings underscore the importance of natural tenderizers in enhancing consumer satisfaction with meat products,
Diversity Of Underutilised Vegetables In Africa And Their Potential In The Reduction Of Micronutrient Deficiency:A Review
(Science publishing Group, 2023) Zacharia,Abdulsudi Issa; Majaliwa,Nuria Kudra; Nyamete,Frida Albinusi; Chove,Lucy Mlipano
Micronutrient deficiency affects all groups worldwide and is a major public health issue. It has devastating effects on all ages, especially in sub-Saharan Africa. It causes anemia, night blindness, increased mortality in children and pregnant women, osteoporosis in adults and rickets in children, lower infectious disease resistance, weariness, and cognitive impairment. Recent attention has focused on micronutrient deficits. Fortunately, these micronutrients are abundant in vegetables. Many African vegetables are endemic due to various weather variations. Diverse geographical areas on the continent allow for exotic and indigenous vegetable kinds. In Africa, many African Indigenous Vegetables (AIVs) are grown and eaten. Exotic veggies are popular in cities, but rural Africans still prefer indigenous crops. Despite their availability, most of the indigenous vegetables are underutilised and have not been adequately explored due to the decreased attention to their production, consumption and utilization. Due to their diversity, they have a great potential to contribute to food security by providing nutrient rich healthy diets. They are rich in vitamins and minerals and hence make a potential source of micronutrients that can help reduce the reported deficiencies. This paper provides a literature review on the wide variety of underappreciated vegetables grown in Africa, their health benefits, and their potential to alleviate micronutrient shortages. It also investigates the barriers to increasing consumption and explores some of the strategies that have been employed to address these problems. Due to their significant role in ensuring food and nutrition security, along with their rich nutrient composition, there exists an urgent imperative to enhance public awareness regarding their consumption and the attainment of nutritional security.
Drying of paddyunder hermetic storage conditions in Burundi
(Sokoine university of agriculture, 2022) Ahishakiye, Dionise
This study assessed the extent to which rice producers from Kidwebeziirrigation scheme could know their productivity loss during post-harvest activities and assessed the performance of drying and storing paddy in Grain Safe Dryer. To achieve these objectives, first simple random sampling was used to select 147 rice farmers in the study area. The collected data were subjected to analysis where output responsiveness with respect to each of the inputs, technical, allocation and economic efficiencies was estimated. Statistical Package for Social Sciences (SPSS) analysis was used to estimate the perception of paddy loss during post-harvest activities. The study further assessed factors affecting loss levels among rice producers. Grain Safe Dryers were installed to assess the performance during drying and storage of paddy. The study applied GENSTAT to analyse the data from using Grain Safe Dryer to dry and store paddy. Findings of this study reveal that the paddy lost during post-harvest activities were between 0 and 9%.Furthermore, the results show that the major factor affecting post-harvest losses in the study area was the material used in post-harvest activities. The study showed that the Grain Safe Dryer had high drying performance comparing to the sun dried paddy. Moisture contents of dried paddy were varied in sun drying and in the two Grain Safe Dryer units with the changes in atmospheric conditions. The initial moisture content was 25.3%, which decreased until it all reached 11.7% (in 19 days) in Grain Safe Dryers and 13.9% (in 3days) under sun drying. In case of germination percentage it was found to be higher (85.2%) in Grain Safe Dryer compared to sun drying (80.8%). Quality of rice after milling was found to be better (80%) in Grain Safe Dryer than sun drying (30%).On the other hand, seeds handled in Grain Safe Dryers gave higher germination rate and quality due to moisture content removed slowly during drying compared to sun drying. However, in terms of moisture removed, good quality, and germination percentage in Grain Safe Dryers were better compared to the sun dried paddy. However, it is recommended to carry more studies on Grain Safe Dryer to be assessed in different ecological zones before wider dissemination of the hermetic storage system for use as a dryer.
Effect of depth and distance of the borehole from the septic tank on the physico-chemical quality of water
(Macrothink Institute, 2017-12-28) Chove, Lucy Mlipano; Mongi, Richard; Chenge, Lawrence
A study to examine the effect of depth and distance of the boreholes from the septic tank on physico-chemical parameters of the borehole water consumed in Dar Es Salaam, Tanzania was conducted. Samples were collected from 48 boreholes in Ilala, Kinondoni and Temeke districts and subjected to pH, B.O.D (Biological Oxygen Demand), total hardness, copper and lead analyses in relation to safety and quality levels set by WHO and TBS. Analysis by R-statistics indicated that pH and B.O.D significantly (p<0.05) decreased as the depth of borehole increased, whereas total hardness was significantly (p<0.05) higher in very deep boreholes than the other heights. Total hardness and pH were not significantly (p>0.05) affected by distance between septic tank and borehole and the B.O.D levels were significantly higher in the borehole water situated near the septic tank than those which were far. Based on the physico-chemical characteristics of water, 25% of the samples did not comply with WHO and TBS specification limits while 75% complied, most of which had shallow depths and were situated near the septic tank. It may thus be concluded that both the distance and the depth between septic tank and borehole influenced physico-chemical characteristics of water.

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