Loveness K. Nyanga’s research while affiliated with University of Zimbabwe and other places

This study reviewed the nutritional composition and safety of sorghum, pearl, and finger millet in sub-Saharan Africa and South Asia, focusing on raw and value-added products. Using PRISMA guidelines, 35 peer-reviewed articles published between 2000 and 2023 were analysed. Data were extracted from Scopus, PubMed, and Google Scholar. Most studies (51.4%) were conducted between 2016 and 2020, with 53.3% focusing on macronutrients and 46.7% on micronutrients. Sorghum and millets were found to be rich in protein content ranging from 7.3% to 12.1% and carbohydrates exceeding 70%. Sorghum recorded the highest zinc levels (24.23 mg/kg), while finger millet had highest calcium content (344 mg/kg). Iron levels were significant in both grains, reaching 61.41 mg/kg in sorghum. Aflatoxin contamination ranged from 0.021 to 20.33 mg/kg, with microbial hazards reported in 83.3% of the studies. Fermentation was the most common processing method used to develop value-added products like porridge, beverages, and flour. Most of the studies on value-added products were from Zimbabwe (50%) and followed by India at 21.4%. This review highlights the potential of sorghum and millet to enhance nutrition and food security in drought-prone areas. However, research gaps remain on chemical and allergen hazards within the value chain, pointing to need for further studies.

Pasta is one of the most consumed staples worldwide. New formulations incorporating novel nutritious ingredients are now common in its production. The purpose of this study was to formulate, optimise and evaluate the sensory properties of sorghum-based extruded gluten-free pasta. Sorghum flour, pearl millet flour, high-iron bean flour (Biofortified NUA 45 beans) and Hermes potato flour were evaluated for proximate and micronutrient composition, formulated to produce pasta through the extrusion process. Three sorghum-based pastas, namely sorghum high bean pasta (SHBP), sorghum bean pasta (SBP) and sorghum high potato pasta (SHPP) were produced and evaluated for sensorial properties (visual, palpatory and gustatory qualities). The Box-Benhken Design (BBD) in conjunction with Response Surface Methodology (RSM) was used to select the best formulation by evaluating cooking quality parameters and sensory parameters. The protein content in the four flours ranged from 10.52% to 22.00%. NUA 45 bean flour had significantly (p<0.05) higher protein content than the other flours. Potato flour had significantly higher carbohydrate content (73.82%) than other flours. SHPP had a significantly (p<0.001) higher optimum cooking time (7 minutes) than SHBP (5 minutes) and SBP (6.2 minutes). SHPP had significantly (p<0.001) higher water absorption (WA) capacity (238%) than pasta SHBP (190%) and SBP (210%). A significant (p<0.001) difference in the swelling index (SI) of the three pasta samples was observed, with pasta SHBP having a significantly lower SI (1.02%) than pasta SBP (1.15%) and pasta SHPP (1.24%). The cooking loss (CL) for pasta SHPP (11%) was significantly higher (P<0.001) than for pastas SHBP and SBP, with pasta SHBP having the lowest CL. There was no significant (p>0.05) difference in the cross-sectional area, surface appearance and surface property of the three cooked pastas. A significant (p<0.05) difference in shape between SHBP and SBP samples was noted. The gluten-free pasta was developed and produced successfully. Sorghum high bean pasta treatment (SHBP) was found to be superior in terms of sensory, nutritional and physical properties as compared to the other pasta samples, making it good for commercialisation.

Background: Extrusion technology, used in producing a variety of food products, including ready-to-eat snacks, has become a popular and reputable industrial method. Snacks have been occupying an important part of the diet for the world's population. However, the effects of extrusion on nutritional and non-nutritional properties in the production of snacks using traditional grains incorporated with legumes are not fully understood. Objective: To determine the effects of extrusion on nutritional and non-nutritional qualities of multigrain puffs from white sorghum, pearl millet and NUA45 beans. Methods: White sorghum, pearl millet and NUA45 beans were blended in the ratios 50:30:20, 50:20:30 and 50:10:40% to select the best composite for snack production. Selected nutritional and non-nutritional quality parameters were compared before and after extrusion. Results: The extrusion process caused a significant increase (p < 0.05) in the content of fat (2.22 to 2.61%, 1.73 to 2.40 and 2.75 to 3.29% for the blends 1, 2 and 3 (50:30:20, 50:20:30 and 50:10:40% respectively), while causing a decrease in protein content, 14.44 to 13.34%, 16.63 to 13.34% and 20.56 to 16.41% in the multigrain puffs. Extrusion also increased iron, zinc and sodium content significantly (p < 0.05) while decreasing calcium. Magnesium and phosphorus had no change. Furthermore, extrusion improved the multigrain puffs' nutritional value and antioxidant activity. The extrusion process caused a significant decrease in tannins (6.82 to 6.01%, 7.82 to 2.17% and 5.74 to1.17%) and phytates contents (2.82 to 2.43%, 3.01 to 1.55% and from 2.92 to 0.37%) of the resultant multigrain puffs from blends 1,2 and 3 respectively. Total phenolic content increased (18.56 to 172.22, 24.38 to 144.61, and 65.87 to 180.44 mg GAE/100g). Conclusion: Extrusion enhances selected nutrients while decreasing anti-nutrients. Based on the composite feeds of white sorghum, pearl millet and NUA45 beans analyzed, the composite blend in the ratio 50:10:40% can be used to develop an acceptable novel healthy extruded traditional grain-based snack. Keywords: Extrusion, ready-to- eat snacks, multigrain puffs, nutrients, anti-nutrients, white sorghum, pearl millet, NUA45 beans.

Finger millet (Eleucine coracana), cowpea (Vigna unguiculata), and bio-fortified vitamin A “orange” maize (Zea mays) are three nutrient dense crops currently being promoted in Zimbabwe. The effect on nutrient content of processing these specific crop varieties has not been investigated. Therefore, this study was designed to determine the effects of germination and roasting on the proximate, mineral, and anti-nutritional factors in finger millet, cowpeas and orange maize. Finger millet grains were germinated for 48hrs, cowpeas and orange maize for 24hrs, at room temperature (20-23oC). Both raw and processed samples were dried and milled into flour for the determination of proximate and mineral and anti-nutritional composition. Protein content of finger millet increased significantly after processing from 6.53±0.25 mg/100 g to 11.27±0.15 mg/100 g in germinated finger millet flour (P<0.05). Germination of finger millet resulted in significantly increased minerals (mg/100 g); calcium from 345.53±0.55 to 352.63±0.21, zinc from 3.59±0.15 to 8.71±0.01, sodium from 49.89±0.16 to 57.78±1.20 and iron content from 3.75±0.05 to 4.52±0.01 whilst magnesium and potassium decreased significantly from 198.09±0.07 to 69.08±0.06 and 487.08±0.03 to 144.78±0.27 respectively. Processing of cowpeas resulted in slight but significant increase in protein content (20.47±0.21 to 28.50±0.10), increased calcium (138.18±0.12 to 148.18±0.12 mg/100 g), magnesium (14.23±2.00 to 19.18±0.31 mg/100 g), potassium (232±4.00 to 443.41±0.02 mg/100 g) and iron (4.85±0.03 to 4.86±0.04 mg/100 g). Conversely zinc and sodium decreased from 4.5±0.30 to 2.9±0.10 mg/100 g and 31.85±0.03 to 11.64±0.02 mg/100 g, respectively. Notably for orange maize, protein content did not change from 10.06±0.04 to 10.04±0.04 g/100 g before and after processing. Calcium increased from 47.02±2.82 to 57.99±8.85 (mg/100 g), magnesium from 90.91±0.11 to 108.30±0.53 (mg/100 g), potassium from 2.13±0.04 to 4.33±0.25 (mg/100 g), sodium from 0.50±0.02 to 0.70±0.02 (mg/100 g) and iron from 0.50±0.02 to 1.25±0.05 (mg/100 g). Zinc decreased from 6.2±0.2 to 3.53±0.55 (mg/100 g). Tannins, oxalates and phytates decreased significantly after processing of all three crops. Results showed that germination and roasting increased the nutritional profile and decreased anti-nutrient content in finger millet, cowpeas and orange maize. Therefore, it is important to consider germinating and roasting these grains during processing to increase the nutritional potential of the end food product. Further studies are required to investigate the decrease in some nutrients after germination and roasting and possibly establish optimum processing parameters for improved nutrient profile of these food crops. Key words: Traditional grains, millet, orange maize, biofortification, germination, roasting, nutrients, anti-nutrients

Poor storage methods lead to high postharvest losses in maize, an essential staple in sub-Saharan Africa. Smallholder farmers’ knowledge and awareness of postharvest nutritional losses (PHNLs), practices regarding maize grain storage, and factors influencing use of improved storage protection practices were investigated in two districts in Zimbabwe through a cross-sectional field survey of 331 households randomly selected from lists of farmers’ names kept by local extension staff. A multistage sampling technique was used involving purposively selecting the study districts then randomly selecting the study wards, the villages and the households. Twenty eight key informant were purposively selected being officers and stakeholders working or residing in the two districts and involved in postharvest and nutrition issues. The most commonly used storage practices were the admixture of maize grain with synthetic grain protectant pesticides followed by storage of untreated grain in polypropylene bags. Highly toxic pesticides, such as Cabaryl 85 WP and Acetamiprid 20 SP, which are not registered for stored food grain treatment, were being applied by 14.6% of the farmers to protect their grain from insect attack. We developed a PHNL knowledge index that measured farmers’ nutritional knowledge and awareness of PHNL. Level of education and district positively correlated with farmers’ PHNL knowledge (p < 0.05), whereas the opposite was found for farmers’ age (p < 0.05). Multinomial logistic regression analysis showed that use of grain storage protection practices was positively related to farmers’ age, total maize grain production, education level and PHNL knowledge (p < 0.05). Older farmers were less likely to use non-recommended chemicals to protect their maize grain during storage. Farmers’ education level and total maize grain production were positively associated with higher use of synthetic pesticides, while PHNL knowledge was associated with the use of traditional grain protectants (p < 0.05). Training on grain storage management, especially safe grain storage protection practices and PHNLs, is essential to contribute towards household food and nutrition security.

Background: Wheat and maize flour still represent the bulk ingredient in complementary foods. There is an increasing interest in traditional cereal grain-based products due to their positive health effects. The positive health benefits include; more protein and fiber content than modern grains and most are naturally gluten-free. Aims: To identify available traditional grain-based complementary food options used for children aged 6-23months in Africa, including the effects of various processing techniques on the nutritional value of the food products. Material and Methods: We searched SciELO, Google Scholar, AGORA, JSTOR, MedLine, ScienceDirect, SpringerLink, Wiley Online, and PubMed databases for the following (a) studies on the formulation of homemade or commercialized traditional grain-based complementary feeding porridges, (b) studies where traditional grains such as sorghum, finger millet, guinea millet, and pearl millet were used as the main ingredient. In addition, we evaluated the food processing techniques used, the resultant nutritional quality, and the acceptability of the product. Results: Thirteen eligible studies were identified. Traditional grains used frequently as complementary foods for children aged 6-23 months in Africa were pearl millet (Pennisetum glaucum), millet (Panicum miliaceum), sorghum (Sorghum bicolor. L), and finger millet (Eleusine coracana). The most common techniques to improve the nutrition content of the foods were: fermentation, germination, and addition of legumes. Additionally, minor investigations have been carried out on effectiveness of these porridges in reducing malnutrition prevalence in this age group. Conclusions: In overall more studies are required with the focus on investigating the development of novel strategies to improve the nutritional profiles, safety, and acceptability of traditional grain-based complementary foods. Furthermore, their effectiveness to improve nutrition status of children needs to be investigated. Keywords: Complementary food, Infants, Traditional Grains, Africa.

Postharvest losses (PHLs) amplify food insecurity and reduce the amount of nutrients available to vulnerable populations, especially in the world's Low and Middle Income Countries (LMICs). However, little is known about nutrient loss at the various postharvest stages. The objective of our study was to develop a methodology and a tool to estimate nutritional postharvest losses (NPHLs) along food value chains for three distinct food commodities in sub-Saharan Africa. The study used a combination of literature, laboratory and field data to investigate NPHLs caused by both changes in quantity and quality of food material (quantitative and qualitative NPHLs, respectively). The method can be expanded to various other food value chains. A user-friendly predictive tool was developed for case studies involving maize and cowpea in Zimbabwe, and for sweet potato in Uganda. Quantitative and qualitative NPHLs were combined and converted into predicted nutrient loss and nutritional requirement lost due to postharvest losses. The number of people who may not meet their daily nutritional needs, as a result of the food and nutrient losses at country level, was estimated. The estimates consider nutritionally vulnerable groups such as children under five years and pregnant women. The nutrient density of the harvested food material, the level of food production, the postharvest stages along the food value chain, the levels of pest damage along the value chain, and the susceptibility of the nutrients to degradation e.g. during storage, are all important factors that affect NPHLs. Our modelling work suggests that reducing PHLs along food value chains could significantly improve access to nutritious food for populations in LMICs.

Background: Antinutritional factors present in food may reduce the bioavailability of nutrients and cause harmful effects to human health. Aims: The aim of this study was to determine the effect of traditional processing methods on protein digestibility, nutrient and antinutrient constituents of seeds of Bauhinia petersiana. Subjects and Methods: The seeds were processed by soaking in water, boiling or roasting before analyzing protein digestibility, nutrient and antinutrient compositions. Results: Soaking resulted in no significant changes in the content of moisture, protein, fiber, phytates and trypsin inhibitor activity and significant reductions in fat, ash and tannins. Roasting resulted in no significant change in the content of moisture, ash, protein, and fiber and significant reductions in fat, phytates and trypsin inhibitor activity. Boiling resulted in a significant increase in the content of both protein and fiber and reduction in fat, ash, tannins, phytates and trypsin inhibitor activity. Mineral content of zinc, magnesium and calcium was not changed by soaking, roasting or boiling of the seeds. The calculated phytate: zinc molar ratios for both the raw and processed seeds were greater than 10, the limit for optimal absorption of zinc in the small intestine whereas phytate: iron molar ratios were less than 14, the limit for optimum absorption of iron in the intestines. In vitro digestibility of proteins in the seeds was increased when the seeds were soaked, roasted or boiled. Conclusions: Boiling the seeds of B. petersiana before consumption would effectively remove undesirable antinutrients while maintaining the nutrient content of the seeds and improving digestibility of proteins. Keywords: Legume, nutrient, antinutrient, digestibility, phytate.

Smallholder farmers in sub-Saharan Africa store harvested maize to provide food stocks between harvest seasons, which may be up to 12 months apart. Stored maize is highly susceptible to insect pest damage, hence the need for stored grain protection technologies such as hermetic bags. The current study evaluated the efficacy of five brands of hermetic bags in storing three maize varieties under two contrasting agro-ecologies in Guruve and Mbire districts of Zimbabwe, for two storage seasons. The hermetic bag treatments evaluated included: GrainPro Super Grain bag (SGB) IVR™, PICS bag, AgroZ® Ordinary bag, AgroZ® Plus bag and ZeroFly® hermetic bag, which were compared to grain stored in a polypropylene bag either untreated (negative control) or following admixture with a synthetic pesticide treatment, Actellic Gold Dust® (positive control). The maize varieties included a white hybrid, a pro-vitamin A biofortified orange and a local variety. All the hermetic bag treatments out-performed the synthetic pesticide in limiting grain damage and weight loss during storage. No significant difference in grain damage or weight loss was observed among the hermetic bags. However, rodents punctured some hermetic bags; therefore rodent control is recommended. A positive correlation with grain damage and weight loss for all three maize varieties was found for Sitophilus zeamais, Sitotroga cerealella, Tribolium castaneum and Cryptolestes spp adult numbers. Significantly higher insect damage and weight loss (P < 0.001) occurred in the white hybrid maize than in the other two varieties. The results confirmed that regardless of brand, all the hermetic bags tested can be recommended for smallholder farmer use to limit postharvest storage losses, avoid pesticide use, and support food and nutrition security.

Cowpea (Vigna unguiculata L. Walp) grain is an important source of protein for smallholder farmers in developing countries. However, cowpea grain is highly susceptible to bruchid attack, resulting in high quantitative and qualitative postharvest losses (PHLs). We evaluated the performance of five different hermetic bag brands for cowpea grain storage in two contrasting agro-ecological zones of Zimbabwe (Guruve and Mbire districts) for an 8-month storage period during the 2017/18 and 2018/19 storage seasons. The hermetic bag treatments evaluated included: GrainPro Super Grain bags (SGB) IVR™; PICS bags; AgroZ® Ordinary bags; AgroZ® Plus bags; ZeroFly® hermetic bags. These were compared to untreated grain in a polypropylene bag (negative control) and Actellic Gold Dust® (positive chemical control). All treatments were housed in farmers’ stores and were subjected to natural insect infestation. Hermetic bag treatments were significantly superior (p < 0.001) to non-hermetic storage in limiting grain damage, weight loss and insect population development during storage. However, rodent control is recommended, as rodent attack rendered some hermetic bags less effective. Actellic Gold Dust® was as effective as the hermetic bags. Callosobruchus rhodesianus (Pic.) populations increased within eight weeks of storage commencement, causing high damage and losses in both quality and quantity, with highest losses recorded in the untreated control. Cowpea grain stored in Mbire district sustained significantly higher insect population and damage than Guruve district which is ascribed to differences in environmental conditions. The parasitic wasp, Dinarmus basalis (Rondani) was suppressed by Actellic Gold Dust® and all hermetic treatments. All the hermetic bag brands tested are recommended for smallholder farmer use in reducing PHLs while enhancing environmental and worker safety, and food and nutrition security.