Browsing by Author "Mongi, R.J."

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    Colour and antioxidant activities of honey from different floral sources and geographical origins in Tanzania
    (Sokoine University of Agriculture, 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.
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    Folate contents, nutritional quality and consumer acceptability of yogurt fortified with red beetroot extract
    (Sokoine University of Agriculture, 2017) Nyamete, F.A.; Mongi, R.J.
    Folate is one of essential vitamin which plays an important role in human life. This vitamin cannot be synthesized by humans and must be obtained externally from foods to prevent folate deficiency. Folic acid, which is chemically synthesized form of folate, is often used for food fortification and supplementation, but higher intake can result into adverse effects such as vitamin B12 deficiency. Therefore, novel methods to increase concentrations of naturally occurring folate in foods have grabbed the interest of researchers. Bio-fortification of B vitamin folic acid in plain yogurt by using red beetroot as a novel strategy to increase “natural” folate levels was explored in this study. Yoghurt samples A (Control), B, C and D were produced at 0%, 5%, 10%, and 20% of milk substitutions with red beetroot powder. Proximate compositions, folate content and sensory analyses were determined to ascertain the quality attributes of the products. Folate content increased significantly (p<0.05) by 84.3, 84.4 and 88.8% with blended red beetroot extract samples at 5, 10 and 20%. The pH of samples containing 20% red beetroot extract significantly (p<0.05) decreased by a factor of 0.86; while titratable acidity was increased by a factor of 2.07 relative to the plain yoghurt. At 20% beetroot extract inclusion level, the protein content of the samples was significantly (p<0.05) increased by 21.25% relative to the control while fat content shows no significant difference. On the other hand, carbohydrate content of the plain yoghurt was significantly (p<0.05) reduced by 33.7 – 44.0% in the presence of red beetroot after the fermentation period. In sensory evaluation, there were no significant change of sensory attributes up to 10% additional with exception of texture. Overall, the study shows that fortification of yoghurt with red beetroot up to 10% enhances folate levels with minor physical and chemical changes.
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    Formulation and nutritional properties of qualea-bird-meat-based complementary foods for children (6–23 months) in Tanzania using a linear programming technique
    (Elsevier, 2023) Ngume, L.S.; Katalambula, L.K.; Munyogwa, M. J; Mongi, R.J.; Lyeme, H.
    Long-standing mitigation strategies have been used to address the issue of malnutrition in children, especially undernutrition in developing countries including Tanzania, however, the problem still exists. Development of instant complementary formulae based on readily available local foods using robust mathematical models, to fight malnutrition seems to be one of the best options. The purpose of this study was to develop and evaluate the nutritional content of instant supplemental food formulations based on qualea bird’s meat for infants between the ages of 6 and 23 months using a linear programming model. Basic procedure: Four complementary meal formulations based on bird meat were developed using a linear programming model: control, only bird meat (CtrQM); green banana mixed with bird meat (BanQ); Irish potato mixed with bird meat (PotQ); and rice mixed with the meat (RicQ). The formulations were cooked separately at 98 ◦C for 45–55 min and extruded to create instant dry products and analyzed using standard methods for proximate composition, minerals, and vitamin A. Main finding: The proximate composition parameters, minerals and vitamin A contents (in DM) were substantially enhanced and differed significantly (p < 0.05) between the formulations. PotQ had a higher moisture content (8.9 g/100 g), protein (16.7 g/100 g), crude fat (1.8 g/100 g), ash (5.4 g/100 g) and crude fibre (2.9 g/100 g) than lower values in other formulations. Furthermore, calcium was the most abundant mineral (832.5 mg/kg) whereas zinc was the least abundant mineral (38.5 mg/100 g). The variation in mineral contents among formulations was also significant (p < 0.05). Additionally, RicQ had significantly (p < 0.05) highest retinol (26.5 mg/kg) and beta-carotene (4.9 μg/g) while the lowest values were observed in the control sample with values of 3.3 mg/kg and 1.6 μg/g respectively. In a view of the findings, a linear programming model optimized and enhanced the proximate composition, mineral, and vitamin A qualities of the qualea birds’ meat-based instant complementary formulation that seems to meet the RDAs for infants aged 6 to 23 months. Therefore, the application of the model in product formulation to combat malnutrition in the country is highly recommended
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    Formulation and nutritional properties of qualea-bird-meat-based complementary foods for children (6–23 months) in Tanzania using a linear programming technique
    (Elsevier, 2023) Ngume, L.S.; Katalambula, L.K.; Munyogwa, M. J.; Mongi, R.J.; Lyeme, H.
    Background: Long-standing mitigation strategies have been used to address the issue of malnutrition in children, especially undernutrition in developing countries including Tanzania, however, the problem still exists. Development of instant complementary formulae based on readily available local foods using robust mathematical models, to fight malnutrition seems to be one of the best options. Purpose: The purpose of this study was to develop and evaluate the nutritional content of instant supplemental food formulations based on qualea bird’s meat for infants between the ages of 6 and 23 months using a linear programming model. Basic procedure: Four complementary meal formulations based on bird meat were developed using a linear programming model: control, only bird meat (CtrQM); green banana mixed with bird meat (BanQ); Irish potato mixed with bird meat (PotQ); and rice mixed with the meat (RicQ). The formulations were cooked separately at 98 ◦C for 45–55 min and extruded to create instant dry products and analyzed using standard methods for proximate composition, minerals, and vitamin A. Main finding: The proximate composition parameters, minerals and vitamin A contents (in DM) were substantially enhanced and differed significantly (p < 0.05) between the formulations. PotQ had a higher moisture content (8.9 g/100 g), protein (16.7 g/100 g), crude fat (1.8 g/100 g), ash (5.4 g/100 g) and crude fibre (2.9 g/100 g) than lower values in other formulations. Furthermore, calcium was the most abundant mineral (832.5 mg/kg) whereas zinc was the least abundant mineral (38.5 mg/100 g). The variation in mineral contents among formulations was also significant (p < 0.05). Additionally, RicQ had significantly (p < 0.05) highest retinol (26.5 mg/kg) and beta-carotene (4.9 μg/g) while the lowest values were observed in the control sample with values of 3.3 mg/kg and 1.6 μg/g respectively. Conclusion: In a view of the findings, a linear programming model optimized and enhanced the proximate composition, mineral, and vitamin A qualities of the qualea birds’ meat-based instant complementary formulation that seems to meet the RDAs for infants aged 6 to 23 months. Therefore, the application of the model in product formulation to combat malnutrition in the country is highly recommended.
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    Sensory properties, preference mapping and shelf life stability of linear programmed quelea meat based instant complementary food for children aged 6–23 months in Tanzania
    (Elsevier, 2022) Ngume, L.S.; Katalambula, L.; Munyogwa, M.; Mongi, R.J.
    Background: Linear programming has been reported to be a good technique that can be used to develop and optimize complementary foods to curb children's malnutrition. Despite some studies using it to develop and assess the nutritional quality of linear programmed instant complementary foods based on high proteinous red-billed quelea bird meat, information on the sensory and shelf life stability of these foods is limited in the country. Objective: The objective of this study was to develop and assess the sensory properties, preference mapping and shelf life of the developed and optimized quale birds meat-based complementary flour and porridge. Methods: Four formulations; control containing birds meat only, banana mixed with meat (Banana_meat), potatoes mixed with meat (potatoes_meat) and rice mixed with meat (rice_meat) were developed by mixing with other ingredients and extruded separately using a barrel extrude to get flour. The extruded flours were assessed for shelf life and also used to develop porridge samples for sensory properties, consumer acceptance and preference mapping analyses using standard methods. Results: There were significant (p < 0.05) differences in mean intensity scores between the formulation with potatoes mixed with meat samples having higher colour (7.5 ± 1.5), aroma (7.3 ± 1.6), viscosity (5.3 ± 3.0) and smoothness (7.65.3 ± 2.5) values than other samples with respective lower values of 4.4 ± 2.1–6.5 ± 1.5.2.6 ± 0.6–6.4 ± 2.4), 4.8 ± 0.2–5.2 ± 1.8 and 2.7 ± 0.6–6.3 ± 2.3. Rice mixed with meat sample had significantly highest whiteness (4.5 ± 1.5) and sweetness (7.5 ± 1.9) intensities scores while the control meat only samples had significantly highest oiliness intensity scores (5.0 ± 1.4) compared to other samples. Moreover, the potatoes mixed with meat sample was the most acceptable formulation (7.7 ± 0.3) compared to other samples with aroma, smoothness sweetness, colour and viscosity attributes being the main drivers for consumer liking of complementary porridge samples. The shelf life study revealed that the overall acceptability scores of complementary flour samples decreased progressively with storage days with the longest predicted shelf life of 140 days observed in rice mixed with meat sample followed by potatoes mixed with meat with 48 days and the shortest shelf life of 23.7 days in control samples. Conclusion: This suggests that quelea bird meat could be combined with cereal, tubers, and other minor ingredients like vegetables, optimized using the linear programming technique and extruded into complementary instant flour and porridge for children between the ages of 6 and 23 months with long shelf lives, appealing sensory properties, and consumer acceptance, respectively. Hence, it is advised to use the method and consume the developed formulations.
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    Suitability of pigeon pea and soybean flours as extenders and binders in restructured meat product (sausage)
    (Sokoine University of Agriculture, 2022) Gomezulu, A.D.; Mongi, R.J.; Kilima, B. M.
    The suitability of pigeon pea and soybean flours as an alternative to chemical binders and extenders in meat restructuring technology was investigated in this study. Pigeon pea flour (PPF) and soybean flour (SBF) were separately developed, assessed for their protein contents and each was used for sausage preparation at 2, 4, and 6% with plain (CB) and chemical phosphate binder (PhB) sausages serving as control samples. The processed sausages were then subjected to texture profile, water solubility index (WSI), sensory profile, and consumer acceptability analyses to assess the flours‘performance. Soybean flour had a significantly (p<0.05) higher protein content (31% DM) than pigeon pea flour (22-24% DM). Texture profile parameters differed significantly (p<0.05) between samples with the highest hardness value observed inCB(424.0±1.53g) and lowest values in SBFs (277±1.11-332±1.5 g). The PhB and 4 and 6% SBFs samples had higher cohesiveness (0.46±0.02-0.54±0.03g), adhesiveness (9.0±0.10-10.9±0.25g) and WSI (2.8-3.0%) than respective lower values of 0.29± 0.04-0.42±0.04, 2.5±0.10-6.0±0.66and 1-2.4% in plain control and PPFs samples. The sensory analysis results revealed that PhB samples had significantly (p<0.05) higher colour (8.2±1.30), saltiness (5.8±1.56), and mouthfeel (6.9±1.20) intensities than other samples. Furthermore, the PhB, and 4 and 6% SBFs samples had significantly (p<0.05) higher moistness (0.46±0.02-0.54±0.03g), consumer acceptability (7.1±1.67-7.3±1.88) and preference (125-177)as well as lower hardness intensity (5.9±2.54-6.0±2.82) than other samples. In conclusion, soybean is richer in protein than pigeon pea and its incorporation of up to 6% in sausage produces a more acceptable product than plain control samples but with WSI, texture, and sensory profiles comparable to chemical binder samples. However, further studies to establish appropriate pigeon pea flour levels that will produce acceptable products with similar physical and sensory properties to chemical binder is recommended.