Dorothy Nakimbugwe

Chemical and nutritional changes associated with the development of the hard-to-cook defect in common beans

Four common bean (Phaseolus vulgaris L.) varieties, Kawanda (K)131, K132, NABE4 and NABE11, were evaluated for the relationship between development of the hard-to-cook (HTC) defect and changes in nutritional quality during 6-month storage under ambient conditions. All varieties developed the HTC defect, but the extent was found to vary with variety. Cooking time increased by 113% in K131, 95.3% in K132, 56.4% in NABE4 and 42.93% in NABE11 after 6 months. The development of the HTC defect was found to be associated with a reduction in phytic acid content (r2=−0.802), in vitro protein digestibility (r2=−0.872) and in vitro starch digestibility (r2=−0.729). The susceptibility to the HTC defect during storage could be attributed to a phytic acid interaction with proteins and carbohydrates, and is also associated with small seed size. Breeding for large seed size could therefore help reduce the development of the HTC defect.

Nutritional composition, quality, and shelf stability of processed Ruspolia nitidula (edible grasshoppers)

Abstract The nutritional and commercial potential of the edible grasshopper (Ruspolia nitidula, nsenene in Luganda), a delicacy in Uganda and many East African tribes, is limited by a short shelf life and unverified nutritional value. This research established that R. nitidula is nutritious with 36–40% protein, 41–43% fat, 2.5–3.2% carbohydrate, 2.6–3.9% ash, 11.0–14.5% dietary fiber, and 900–2300 μg/100 g total carotenoids on a dry matter basis. Sautéing was the most preferred processing method resulting in grasshoppers with a notably better aroma and flavor. After 12 weeks of storage at room temperature, processed and vacuum packed, ready‐to‐eat grasshoppers maintained their edible quality with an acid value of 3.2 mg KOH/g, a total plate count of log 1.8 cfu/g, and an overall acceptability of 6.7–7.2 on a 9‐point hedonic scale. Further research is required for extending the shelf stability beyond 12 weeks and characterizing the profile of major nutrients.

Effects of combined traditional processing methods on the nutritional quality of beans

Consumption of dry beans is limited by long cooking times thus high fuel requirement. The bioavailability of nutrients in beans is also limited due to presence of antinutrients such as phytates and tannins. Little research has been done on combined processing methods for production of nutritious fast cooking bean flour and the effect of combined treatments on nutritional quality of beans has not previously determined. The aim of this study was to reduce cooking time and enhance the nutritional value of dry beans. Specifically to: develop protocols for production of fast cooking bean flours and assess the effect of processing on the nutritional characteristics of the flours. Dry beans (K131 variety) were soaked for 12 h; sprouted for 48 h; dehulled and steamed for 25 and 15 min for whole and dehulled beans respectively or roasted at 170°C for 45 and 15 min for whole and dehulled beans respectively. Dehulling eliminated phytates and tannins and increased protein digestibility. In vitro protein digestibility and mineral (iron and zinc) extractability were negatively correlated with tannin and phytate content. Total available carbohydrates were highest in moist heat-treated bean flours. Overall, combined processing of beans improved the nutritional quality of dry beans and the resulting precooked flours need less cooking time compared to whole dry beans.

Formulation of a drinkable peanut-based therapeutic food for malnourished children using plant sources

High ingredient costs continue to hamper local production of therapeutic foods (TFs). Development of formulations without milk, the most expensive ingredient, is one way of reducing cost. This study formulated a ready-to-drink peanut-based TF that matched the nutrient composition of F100 using plant sources. Three least cost formulations namely, A, B and C were designed using computer formulation software with peanuts, beans, sesame, cowpeas and grain amaranth as ingredients. A 100 g portion of the TF provided 101–111 kcal, 5 g protein and 5.3–6.5 g fat. Consumer acceptability hedonic tests showed that the products were liked (extremely and moderately) by 62–65% of mothers. These results suggest that nutrient dense TFs formulated from only plant sources have the potential to be used in the rehabilitation phase of the management of malnourished children after clinical testing.

Physico-chemical properties and extrusion behaviour of selected common bean varieties

BACKGROUND Extrusion processing offers the possibility of processing common beans industrially into highly nutritious and functional products. However, there is limited information on properties of extrudates from different bean varieties and their association with raw material characteristics and extrusion conditions. In this study, physico-chemical properties of raw and extruded Bishaz, K131, NABE19, Roba1 and RWR2245 common beans were determined. The relationships between bean characteristics and extrusion conditions on the extrudate properties were analysed. RESULTS Extrudate physico-chemical and pasting properties varied significantly (P < 0.05) among bean varieties. Expansion ratio and water solubility decreased, while bulk density, water absorption, peak and breakdown viscosities increased as feed moisture increased. Protein exhibited significant positive correlation (P < 0.05) with water solubility index, and negative correlations (P < 0.05) with water absorption, bulk density and pasting viscosities. Iron and dietary fibre showed positive correlation while total ash exhibited negative correlation with peak viscosity, final viscosity and setback. Similar trends were observed in principal component analysis. CONCLUSION Extrudate physico-chemical properties were found to be associated with beans protein, starch, iron, zinc and fibre contents. Therefore, bean chemical composition may serve as an indicator for beans extrusion behaviour and could be useful in selection of beans for extrusion.

Effect of processing, packaging and storage-temperature based hurdles on the shelf stability of sautéed ready-to-eat Ruspolia nitidula

Ruspolia nitidula (an edible grasshopper) is a seasonal delicacy in Uganda and its neighbouring countries, with a postharvest shelf stability of 1-2 days. Our previous processing research increased the shelf stability of ready-to-eat R. nitidula to 12 weeks at ambient temperature. However, there is need to double the shelf-life to cover the 20-24 weeks between swarming seasons and, increase the efficiency and cost effectiveness of the processing and packaging techniques developed. This research investigated the effectiveness of 9 preservation hurdles on the microbial (total plate count), sensorial (overall acceptability) and chemical (acid value, peroxide value and thio-barbituric acid value) stability of ready-to-eat R. nitidula. Chilled storage and ambient temperature storage of the vacuum packed product increased the shelf stability of R. nitidula from 12 to 22 weeks. After 22 weeks of storage, the products had an overall acceptability of 6-7 on a 9-point hedonic scale, a total plate count of <4 log cf...

Optimized formulation and processing protocol for a supplementary bean‐based composite flour

Abstract Protein‐energy malnutrition is the most serious nutritional body depletion disorder among infants and young children in developing countries, attributable to inadequate energy and nutrient intake, partly due to high dietary bulk of weaning and infant foods. The gruels fed to children are typically of low nutrient and energy density due to the low flour incorporation rate required for drinking viscosity. The aim of this study was to develop a nutritious product, based on common dry beans and other grains, suitable for supplementary feeding. The optimal processing conditions for desired nutritional and sensory attributes were determined using Response Surface Methodology. For bean processing, soaking for 6, 15, or 24 h, germination for 24 or 48 h, and cooking under pressure for either 10 or 20 min were the independent variables. The processed bean flours total polyphenol, phytic acid and protein content, the sensory acceptability of the bean‐based composite porridge and its protein and starch digestibility were dependent variables. Based on product acceptability, antinutrients and protein content, as well as on protein and starch digestibility, the optimum processing conditions for the bean flour for infant and young child feeding were 24 h of soaking, 48 h of malting, and 19 min of steaming under pressure. These conditions resulted in a product with the highest desirability. The model equations developed can be used for predicting the quality of the bean flour and the bean‐based composite porridge. Bean optimally processed and incorporated with grain amaranth and rice flours of a ratio of 40: 30: 30, respectively, resulted into flour with high energy, mineral, and nutrient density of the final porridge. The composite is well adaptable to preparation at rural community level. The use of these locally available grains and feasible processes could make a great contribution to nutrition security in sub‐Saharan Africa and other developing countries.

Optimization of extrusion conditions for the production of instant grain amaranth-based porridge flour

Abstract Malnutrition is one of the foremost causes of death among children below 5 years in developing countries. Development of nutrient‐dense food formulations using locally available crops has been proposed as a means to combat this menace. This study optimized the extrusion process for the production of a nutritious amaranth‐based porridge flour. Least cost formulations containing grain amaranth, groundnut, iron‐rich beans, pumpkin, orange‐fleshed sweet potato, carrot, and maize were developed and evaluated by a sensory panel (n = 30) for acceptability using the 9‐point hedonic scale. Extrusion process of the most acceptable porridge flour was optimized by response surface methodology (RSM). Barrel temperature (130–170°C) and feed moisture content (14%–20%) were the independent variables which significantly (p < .05) affected in vitro protein digestibility, vitamin A retention, total polyphenol, phytic content, and iron and zinc extractabilities. Optimization of the extrusion process improved the nutritional quality of the instant flour.

Development of the process for a drinkable plant-based infant food.

Provision of nutritionally adequate foods is crucial for the prevention and management of malnutrition. In order to meet the nutrient requirements of infants and young children using locally available cereals and legumes, foods need to be of low viscosity, of high caloric content and nutrient density and easily digestible. This study developed a processing protocol for three plant food formulations to yield nutrient dense, easily digestible and safe therapeutic foods for malnourished children. Pre-digestion of the milled ingredients at 40°C for 4 hours with grain amaranth that was malted for 48 hours and 1% Bromelain achieved 70-84% starch hydrolysis and 55-61% protein hydrolysis. Sterilization of the therapeutic food in glass jars in an autoclave at 121°C, 15 PSI for 20 minutesgave non- detectable total plate and yeast and mold counts. The final products had viscosities of 2745-2913 Cps. These results show that pre-digestion can improve the nutrition quality of infant foods made from plant sources.

Microbial characterisation of the edible grasshopper Ruspolia differens in raw condition after wild-harvesting in Uganda

This research aimed at establishing the chemical intrinsic properties and the microbial quality of an edible grasshopper Ruspolia differens and the effect of its source (geographical area) in Uganda, trading point, swarming season and plucking on these parameters. The intrinsic properties of the grasshopper can support the growth of a wide variety of microorganisms. High counts of total aerobic microbes, Enterobacteriaceae, lactic acid bacteria, total aerobic spores, and yeasts and moulds were obtained. Metagenetic analyses yielded 1793 Operational Taxonomic Units (OTUs) belonging to 24 phyla. Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria and Proteobacteria were the most abundant phyla, while members of the genera Acinetobacter, Buttiauxella, Lactococcus, Staphylococcus and Undibacterium were the most abundant OTUs. A number of genera harbouring potential pathogens (Acinetobacter, Bacillus, Buttiauxella, Campylobacter, Clostridium, Staphylococcus, Pseudomonas and Neisseria) were identified. The geographical area, trading point, swarming season and plucking significantly influenced microbial counts and bacterial diversity. The high microbial counts predispose R. differens to fast microbial spoilage, while the presence of Clostridium and Campylobacter makes this grasshopper a potential source of food borne diseases. Further research should identify the specific spoilage microorganisms of R. differens and assess the characteristics of this grasshopper that support growth of food pathogens.