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.

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Grain amaranth is a pseudocereal with unique agricultural, nutritional, and functional properties. This study was undertaken to determine the effect of different heat-processing methods on physicochemical and nutraceutical properties in two main grain amaranth species, of Amaranthus hypochondriacus L. and Amaranthus cruentus L. Grains were prepared by roasting and popping, milled and analyzed for changes in in vitro protein digestibility, gruel viscosity, pasting characteristics, antioxidant activity, flavonoids, and total phenolics. In vitro protein digestibility was determined using the pepsin-pancreatin enzyme system. Viscosity and pasting characteristics of samples were determined using a Brookfield Viscometer and a Rapid Visco Analyzer, respectively. The grain methanol extracts were analysed for phenolics using spectrophotometry while antioxidant activity was determined using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. Heat treatment led to a reduction in protein digestibility, the effect being higher in popped than in roasted samples. Viscosities for roasted grain amaranth gruels were significantly higher than those obtained from raw and popped grain amaranth gruels. The results for pasting properties were consistent with the results for viscosity. In both A. hypochondriacus L. and A. cruentus L., the order of the viscosity values was roasted>raw>popped. The viscosities were also generally lower for A. cruentus L. compared to A. hypochondriacus L. Raw samples for both A. hypochondriacus L. and A. cruentus L. did not significantly differ in total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant activity values. Thermal processing led to an increase in TFC and antioxidant activity. However, TPC of heat-processed samples remained unchanged. From the results, it can be concluded that heat treatment enhances antioxidant activity of grain amaranth and causes rheological changes dependent on the nature of heat treatment.

The cost of compound feed is a constraint in intensive fish and poultry farming, contributing 60-80% of the total production costs, 70% of which is due to fish and soy meal used as protein source. This review presents the extent to which insects have been utilised as an alternative protein source in feed in sub-Saharan Africa (SSA). A key word search of agricultural, biological and multi-disciplinary databases and academic search engines was conducted for literature on the extent of research and utilisation of insects in poultry and fish feed in SSA. There is limited published information on the practice as well as technical and economic feasibility of the use of insects as alternative protein ingredients in compound feed. This is likely because research on the subject is fairly recently initiated and yet to be published. Excluding South Africa, rearing, processing and use of insects is still at experimentation level at laboratory scale. Insects (grasshoppers, house fly maggots, Westwood larvae, termites and garden snail) meal replaced conventional protein sources by 10-100% without affecting the growth performance of fish and poultry. In some cases, insect based feed performed better than conventional feed. Nutritional composition data of insects published for SSA majorly focused on proximate composition and not characterisation of the nutritional quality. Several research and development projects on the technical and economic feasibility, social acceptability and potential social-economic impact are ongoing and expected to increase available data when completed. Published research confirms the potential of insects for use in poultry and fish production systems and mass production and processing of target insects is the next necessary step. Based on available and ongoing research, piloting and up-scaling the use of insects as alternative protein sources in animal feed in partnership with private sector in SSA is necessary. This will confirm and enhance the technical and economic feasibility of using of insects as an alternative protein source on a commercial scale.

Efforts to promote sustainable production and processing of Ruspolia differens Serville (Orthoptera: Tettigoniidae) as a viable agribusiness model for enhancing food and nutrition security have gained momentum. However, the inexistence of rearing techniques adapted to this insect creates uncertainty regarding the effectiveness of up-scaling production. This study evaluated the effect of five temperatures (26, 28, 30, 32 and 34 °C) on egg development time, percentage hatchability and nymphal weight at hatching. It also evaluated the average weekly wet weight attained by R. differens and percentage survival during growth when reared at 30 °C on four different food plant diets. The diets composed of (1) star grass Cynodon dactylon (L.) Pers.; (2) wild millet Eleusine indica (L.) Gaertn.; (3) guinea grass Panicum maximum Jacq.; and (4) a mixture of the three food plants. The highest hatchability (89.33±3.06%) was observed for egg clusters that were not detached from the leaf sheaths and incubated at 30 °C. At the same temperature, the hatchability of eggs detached from the leaf sheath was 43.33±4.16%. The wet nymphal weight at hatching varied significantly across the different incubation temperatures. For eggs that were not detached from the leaf sheath, it ranged between 3.12±1.20 mg at 30 °C to 4.15±0.98 mg at 34 °C, while for eggs that were detached, it ranged between 2.96±1.14 at 32 °C to 6.0±2.0 mg at 26 °C. The highest wet nymphal weight (586.4 mg) and growth rate (10.47 mg/day) of adult R. differens after 8 weeks was recorded on wild millet, followed by the mixture of the three food plants (553.7 mg; 9.9 mg/day). Food plants significantly influenced survival of nymphs, with C. dactylon and P. maximum associated with the highest survival rate (53.3%). These findings are central to upscaling R. differens production.

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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 cfu/g, an acid value of approximately <1 mg KOH/g, a peroxide value of <21.50 meq O2/kg and a thio-barbituric value of <0.079. Either chilled storage or vacuum packaging are suitable means of preserving dried ready-to-eat edible grass hoppers and can be used depending on availability. Further research into increasing the shelf stability of R. nitidula at room temperature will be very beneficial to its commercialisation.

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.