Edible Grasshoppers Research Articles

Edible grasshoppers (Ruspolia differens) as alternative source of protein from insects to combat malnutrition

One of the most common public health issues affecting both children and adults in poor nations is malnutrition. Malnutrition is frequently attributed to food insecurity or a lack of access to enough food. Malnutrition is a serious issue in Tanzania mainland and Zanzibar, that requires attention. More cases of malnutrition than any other category are caused by protein-energy deficiencies. Compared to plant-based protein, animal protein offers essential amino acids in a better pattern. Nonetheless, it is a significant problem to produce enough animal proteins to feed the expanding global population of 9 billion people. Throughout the months of November and December each year, the Kagera region of Tanzania collects a large number of edible grasshoppers (Ruspolia differens) from the Muleba and Bukoba Districts. Grasshoppers processed in different methods are a rich source of nutrients such as protein (7.80-44.70%), fat (36.30-83.00%), fibre (8.70-11.20), ash (2.20-2.40%), total carbohydrates (5.30-12.10%), total energy (614-807 Kcal/100 g), Ca (35.80-55.00 mg/100 g), P (305.40-496.80 mg/100 g), Mg (33.30-56.50 mg/100 g), Fe (12.90-179.10 mg/100 g), Cu (1.60-2.30 mg/100 g), Mn (2.90-5.30 mg/100 g), Zn (8.50-18.40 mg/100 g) and Co (28.60-33.10 mg/100 g). The Kagera region's residents roast these insects and either consume them alone or in combination with other dishes like bananas. A few months after collection, grasshoppers begin to spoil due to their perishability. The shelf life of these products could be increased by at least a year with the right processing methods. In order to battle hunger and raise the community's revenue, these grasshoppers are a great source of nutrients that may be utilized to augment other crops with low nutritional value, such as bananas, cassava, rice, millets, sorghum and maize. In order to combat malnutrition, this review will examine the research on the utilization of edible insects as alternate source of protein and micronutrients. Key words: Edible grasshoppers, Malnutrition, Protein-Energy Malnutrition, Food security, Edible insects

Documenting the biodiversity of edible grasshoppers in South Africa with traditional knowledge, classic taxonomy and genetic information

AbstractThe diversity of edible grasshoppers worldwide remains largely undocumented due to inconsistent reporting of ethno- and scientific species, and paucity of reference DNA sequences. This study uses traditional knowledge and scientific methods for identification of ethnospecies, taxonomic species, and phylogenetic groups that likely represent genetic species. Community members in the Limpopo province of South Africa assisted with specimen collection (n = 176) and identification of 34 ethnospecies (i.e. vernacular names given by the local communities). Scientific taxa were identified by alpha taxonomy and DNA barcode sequence queries on BOLD Systems and GenBank. Genetic groups likely representing distinct species were determined by phylogenetic analysis and intragroup p-distances. Acrididae dominated the dataset with nine subfamilies and 17 genera represented. Database queries yielded high sequence similarity/identity matches (> 95%) for only 58.6% of the sequences on BOLD and 37.1% on GenBank, thus highlighting the low representation of African Orthoptera in public repositories. Phylogenetic analysis and pairwise distances revealed 36 genetic groups likely representing distinct species. Comparison of the results obtained from the different sources of information showed incomplete overlap, and numerous inconsistencies. Despite the difficulties, the overall diversity of edible grasshoppers traditionally utilized in South Africa is higher than previously reported. This work may inform future studies for documenting edible insects in Africa and other world regions.

Dielectric properties of Sphenarium purpurascens at 2.4 GHz

The dielectric properties of edible grasshoppers (Sphenarium purpurascens) are presented at 2.4 GHz using the cavity perturbation technique. The samples are subjected to increasing temperatures (from 25 to 80 °C). It will be shown that the real part of the permittivity has a decreasing trend to rising temperature. As temperature increases, water evaporates; therefore the value of permittivity decreases. Moreover, dielectric losses increase with increasing temperature from 16 at 25 °C to 32 at 80 °C. This is caused by a predominant ionic conduction at lower frequencies, where ionic mobility increases at higher temperatures. In addition, the penetration depth decreases from 10.8 mm at 25 °C to 3.5 mm at 80 °C.

Biological activity of extracts and hydrolysates from early- and adult-stage edible grasshopper Sphenarium purpurascens.

Edible insects have become a promising food source because they are rich in protein, fatty acids, minerals, among others. In recent years, edible insects have been proposed to be used as innovative functional ingredients in terms of biological activity. The present study aimed to determine and compare biological activities of the extracts and hydrolysates obtained from early- and adult-stage edible grasshoppers Sphenarium purpurascens to evaluate their potential as a source of bioactive compounds. Proximal analyses showed that in adult grasshoppers (AGs), the percentage of protein (48.9% ± 1.2), crude fat (13.1% ± 0.09), and chitin (15.6% ± 0.81) was significantly higher than early grasshoppers (EGs) (42.2% ± 0.55, 9.35% ± 0.08, and 10.5% ± 0.15, respectively). Total phenolic compounds, 2,2-diphenyl-1-picrylhydrazyl (DPPH•), and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS•+) free radical scavenging were analyzed and reported. Enzymatic hydrolysis increased the concentration of total phenolic compounds and higher antioxidant capacity (up to 252.78 mM trolox). Once fractionated by ultrafiltration, the fraction that presented the highest antioxidant activity against DPPH• and ABTS•+ was that with molecules ≤ 10 kDa. Furthermore, the bioaccessibility of the samples was analyzed by in vitro protein digestion using a multienzymatic method, and a recovery index (RI) was reported. Extracts and hydrolysates were analyzed by UPLC-MS, and this allowed the identification of phenolic acids and flavonoids. The results obtained in this work suggest that the grasshopper can be used as a possible source of bioactive compounds that can be used in the food or pharmaceutical industry.

Evaluation of essential nutrients in edible locusts and grasshoppers in Kano Metropolis

The present study was conducted to evaluate the nutritional composition of edible locusts and grasshoppers sold and consumed in Kano metropolis, Northwestern Nigeria. Two species of locusts: (Schistocerca gregaria and Locusta migratoria) and two species of grasshopper (Zonocerus variegatus and Ornithacris turbida) were procured from Rimi market Kano. Proximate, mineral and amino acids compositions of the samples were analyzed using standard methods. The results obtained revealed a significant difference (P≤0.05) in the amount of proteins, fats, ash, carbohydrates and moisture contents. Similar result is found in the mineral compositions in terms of Na, Mg, K, Ca, Cu, Zn and Fe. More so, the amino acid composition of the samples was found to be significantly different (P≤0.05). No significant difference was found in the fibre contents. However, high protein (53.23-67.88%), fats (7.55-18.77%) and carbohydrate contents (10.71-16.01%) were found among the insect samples. Similarly, the amount of essential amino acids such as: threonine, valine, methionine and leucine were higher among the insects. It is therefore concluded that, the edible grasshopper and locust contain significant amount of nutritional components that can be beneficial in combating malnutrition and be incorporated in diet therapy.

Food safety concerns in edible grasshoppers: a review of microbiological and heavy metal hazards

The use of insects as food and feed is widespread worldwide due to their attractive nutritional profile comparable to that of conventional livestock. In particular, edible grasshoppers act as a food source to many tribes in East and Central Africa but still harvested from their natural habitats. In this perspective, the health hazards associated with consumption of grasshoppers ought to be investigated. The present review assesses the risks (microbiological and heavy metals hazards) of wild-harvested Ruspolia differens (Serville) (Orthoptera: Tettigonidae) and compares with the levels recommended for minced meat as an indicator of food safety for edible insects. In addition, the effect of common processing methods in reducing the risks is stated. Due to the scarcity of the data, other edible grasshoppers within the order Orthoptera have been included in the review. The risks identified as main hazards include: (1) high total viable counts; (2) high counts of Enterobacteriaceae and lactic acid bacteria; (3) high counts of yeasts and moulds; and (4) accumulation of lead and other heavy metals. Conventional processing methods are effective in reducing microbiological hazards except for bacterial endospores. Important data gaps regarding edible grasshoppers and their safety include: (1) lack of data on bacterial communities (raw and processed); (2) fungal communities and mycotoxins-producing fungi; (3) studies on shelf life of processed edible grasshoppers; (4) limited data on heavy metals on whole grasshoppers and derived products; and (5) lack of data on parasites, viruses, antimicrobial resistance and veterinary medicinal products. Future aspect should focus on sustainable farming of grasshoppers using different diets in controlled environments and risks profiling. The present review explores food safety risks related to consumption of edible grasshoppers, from wild collections to consumption.

Identification of Edible Short- and Long-Horned Grasshoppers and Their Host Plants in East Africa

There is a paucity of information on the edible grasshoppers and their host plants in East Africa. This study adopted morphological and molecular analysis to identify edible grasshoppers in Kenya and Uganda. The associated host plants were identified through molecular analysis of the gut contents of the grasshoppers. The cytochrome b and 16s gene primers were used for grasshopper DNA analysis; while matK gene primers were used for plant DNA analysis. All long-horned grasshoppers sampled were identified as Ruspolia differens (Serville) (Orthoptera: Tettigonidae); whereas short-horned grasshoppers were identified as Acanthacris ruficornis (Fabricius) (Orthoptera: Acrididae) and Cyrtacanthacris tatarica (L.) (Orthoptera: Acrididae). Host plants of A. ruficornis were Achyranthes aspera (L.), Centella virgata L.f. Drude, Digitaria gayana (Kunth), Galinsoga quadriradiata Ruiz and Pavon, and Triumfetta pilosa Roth; whereas those of C. tatarica were Alysicarpus rugosus (Willd.) DC and Teramnus uncinatus (L.) SW. Host plants of R. differens were Ageratum conyzoides (L.), Citrus depressa Hayata, Cynodon dactylon (L.), D. gayana, Eragrostis mexicana Hornem, Eucalyptus saligna SM., Indigofera arrecta Hochst. ex A. Rich., Persicaria nepalensis (L.), and Sorghum halepense (L.). Information on the host plants of edible grasshoppers can help in the development of their mass rearing protocols.

Diversity and Use of Edible Grasshoppers, Locusts, Crickets, and Katydids (Orthoptera) in Madagascar.

Madagascar has a long history of using Orthoptera as food and feed. Our understanding of the biological diversity of this resource, its contemporary use, and its future potentials in Madagascar is extremely limited. The present study contributes basic knowledge of the biological diversity and local uses of edible Orthoptera in Malagasy food cultures. Data was collected with key informants in 47 localities covering most of the ecoregions of Madagascar and corresponding to 12 of the 19 ethnic groups. Orthoptera are consumed throughout Madagascar. We report 37 edible Orthoptera species, of which 28 are new species records of edible Orthoptera in Madagascar and 24 are new species records of edible Orthoptera in the world. Most species are endemic and occur in farming zones. Children are the primary collectors and consumers of edible Orthoptera. The insects are eaten both as snacks and main meals. Edible Orthoptera are primarily collected casually and marketing is rare, with the notable exceptions of the large cricket Brachytrupes membranaceus colosseus and during locust outbreaks (e.g., Locusta migratoria). The use of Orthoptera as feed seems rare. Further investigations of cultural and personal preferences are required to assess the future potential roles of Orthoptera in Malagasy food habits.

Inorganic pollutants in edible grasshoppers (Ruspolia nitidula) of Uganda and their major public health implications.

Inorganic contamination of food products is associated with adverse health effects, however, information on grasshoppers in Africa is sparse. The objective of the study was to determine antioxidant, heavy metal and food safety status of edible grasshoppers of Uganda. A cross-sectional study was conducted in central and southwestern Uganda, in which a questionnaire was administered to grasshopper harvesters. Grasshopper samples were collected from each harvesting point and analyzed in the laboratory for antioxidant and heavy metal content i.e. Lead (Pb), Chromium (Cr), Zinc (Zn) and Cadmium (Cd) using atomic absorbance spectrometric (AAS) method on the heads and abdomen of the insects. Major antioxidants were Catalase > Glutathione > Glutathione peroxidase. In addition concentrations of heavy metals were in the order of Pb > Cr > Zn > Cd in the heads and abdomens of the grasshoppers. Pb concentrations were found to be higher in the heads than the abdomens and the carcinogenic potential of the grasshoppers was over 10 times over the recommended levels. Grasshoppers were found not to be safe especially in children due to their small body weight in comparison to adults. Pb poisoning in the Ugandan children would be propagated through contaminated grasshoppers.

Effects of Continuous Deep-fat Frying on the Physicochemical Properties of Assorted Brands of Edible Cooking Oils Sold in Greater Metropolitan Kampala

Aims: To investigate the effects of continuous deep fat frying of white (Irish) potatoes on the physical and chemical attributes of ten brands of edible cooking oils: Fortune Butto, Roki, Tamu, Best Fry, Mukwano, Golden Fry (hard oils); Sunseed, Sunny, Sunvita and Sunlite (soft oils) sold in Kampala, Uganda.
 Place and Duration of the Study: Oil samples of approximate manufacturing dates were obtained from Mega Standard supermarket in Greater Metropolitan Kampala, Uganda. Oil samples were also obtained from local Irish potato fryers in Makindye division of Kampala during ten deep frying cycles. Irish potatoes was procured from Nakasero market, Kampala. Physicochemical analyses were performed at the Quality Control Laboratory of Mukwano Industries Limited, Kampala Industrial area, Kampala. The research was conducted between May 2018 to December 2018.
 Methodology: 400g of Irish potato slices (1cm × 1cm × 3cm) were submersed in 1500mL of oil maintained at 140°C for 6 minutes in an Electric Deep Fryer with a frying time of 10 minutes.The color value (CV) and the acidification of the oils as free fatty acid (FFA), peroxide value (POV), paraanisidine value (AnV), iodine adsorption value (IV) and total oxidation (TOTOX) value before and between ten successive frying cycles were determined using ISO and AOCS official methods.The maximum number of reuses of an oil was estimated from the frying round before its POV or AnV surpassed the maximum permissible statutory or Codex Alimentarius limit for edible oils.
 Results: For fresh oils, the statistical physicochemical parameter ranges were: CV (0.4R 3.4Y-7.7R 70Y), FFA (0.0430±0.30-0.1508±0.30), POV (0.5951±0.03-6.6134±0.23 meqO2/Kg), AnV (0.90±0.01-4.30±0.19) and IV (57.62±0.17-128.35±0.02gI2/100g). By the 10th fry, the ranges were CV (3.0R 23Y-20.4R 70Y), FFA (0.2286±0.01-0.4817±0.01), POV (11.1138±0.01-15.7525±0.01meqO2/Kg), AnV (10.31±0.03-22.16±0.01) and IV (53.66±0.01-126.03±0.02gI2/100g). Considering oxidizability as TOTOX values, frying stability of the selected brands of cooking oils during the frying cycles followed the order: Roki > Fortune Butto > Sunvita > Sunny > Sunlite > Mukwano > Tamu > Best Fry > Golden Fry > Sunseed.
 Conclusion: Reuse of the oils for continuous frying of Irish potatoes on the same day can be done only up to 7 times on average for hard oils and 6 times for soft oils with the oils still regarded as safe for human consumption. Hard oils should be preferred to soft oils for deep frying of Irish potato chips.Further research should elucidate the variation of physicochemical properties of other oil brands on the Ugandan market such as Nile, Fortune, Kimbo, Star Fry, Cow boy and Ufuta and should use other food samples such as fish, cassava, chicken, sweet plantain, dough, meat and edible grasshoppers.

Characteristics, Functional Properties, and Antioxidant Activities of Water-Soluble Proteins Extracted from Grasshoppers,Patanga succinctaandChondracris roseapbrunner

Water-soluble proteins extracted from two species of grasshoppers,Patanga succincta(WSPP) andChondracris roseapbrunner(WSPC), were characterized as well as their functional properties and antioxidant activities were investigated. The extraction yield, on a wet weight basis, was 7.35% and 7.46% for WSPP and WSPC,respectively. The most abundant amino acid in both proteins was glutamic acid, followed by aspartic, alanine, and leucine, in that order. The electrophoretic study revealed that proteins with MW of 29, 42, 50, 69, and 146 kDa were the major protein components in WSPP and WSPC. FTIR analysis showed that those proteins remained their structural integrity. The surface hydrophobicity at pH 7 of WSPC was higher than WSPP, but the sulfhydryl group content did not show significant difference between the proteins from two species. Both grasshopper proteins were mostly soluble in strong acidic and alkaline aqueous solutions with a minimum value at pH 4. Those proteins exhibited poor emulsifying properties and foaming capacity, but they had greater foaming stability compared with bovine serum albumin (BSA) (p<0.05). WSPC showed greater DPPH•and ABTS•+scavenging activities and ferric-reducing antioxidant power (FRAP) than did WSPP (p<0.05). Therefore, based on characteristics and functional properties, water-soluble proteins from both edible grasshoppers can be used as an ingredient in food applications.

Transferable Antibiotic Resistances in Marketed Edible Grasshoppers (Locusta migratoria migratorioides).

Grasshoppers are the most commonly eaten insects by humans worldwide, as they are rich in proteins and micronutrients. This study aimed to assess the occurrence of transferable antibiotic resistance genes in commercialized edible grasshoppers. To this end, the prevalence of 12 selected genes [aac(6')-Ie aph(2″)-Ia, blaZ, erm(A), erm(B), erm(C), mecA, tet(M), tet(O), tet(S), tet(K), vanA, vanB] coding for resistance to antibiotics conventionally used in clinical practice was determined. The majority of samples were positive for tet(M) (70.0%), tet(K) (83.3%) and blaZ (83.3%). A low percentage of samples were positive for erm(B) (16.7%), erm(C) (26.7%), and aac(6')-Ie aph(2″)-Ia (13.3%), whereas no samples were positive for erm(A), vanA, vanB, tet(O), and mecA. Cluster analysis identified 4 main clusters, allowing a separation of samples on the basis of their country of origin.

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 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.

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

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.

Utilisation and trade of edible grasshoppers in the western region of the state of Morelos, Mexico

This article presents a taxonomic analysis of the grasshoppers utilised as food sources in several municipalities of the state of Morelos, Mexico; three families, four genera, and ten species were documented. The representative genus,Sphenarium, consists of seven different species. Various aspects regarding the host plants and collection and trade of these organisms are discussed. In addition, the importance of these organisms as a renewable natural food resource for rural communities in the state of Morelos is discussed.

Chemical composition and amino acids content of five species of edible Grasshoppers from Mexico

Food security is the main concern of government due to malnutrition worldwide. The aim of this study was to assess macronutrients and amino acids in five species of grasshoppers, consumed in rural and urban communities. Samples were captured in different agro climatic environment conditions, wherever vegetation grows, and the macronutrients were raw, analyzed in dry basis by the AOAC methods and amino acids by cation exchange chromatography. The obtained data showed a high protein content, ranging from 70% to 75%; lipids 4% to 6%; minerals 3% to 5%; fiber 6% to 8% and soluble carbohydrates 6% to 18%, including essential amino acids that play an important role in human metabolism, with tryptophan as limiting factor. The different species of the studied grasshoppers are high in proteins, essential macromolecules for human life that decrease protein-energy malnutrition; the excess of amino acids after releasing the amino group will provide energy, as well as soluble carbohydrates. They also have minerals that are needed to prevent anemia, and fiber, non-digestible carbohydrates essential in a healthy diet. In conclusion, the daily consumption of 5 or 6 grasshoppers is a good source of nutrients that will provide optimal health to population.

福島県産イナゴの放射性セシウム量および福島県のイナゴ食文化の存続可能性

Inago (edible grasshoppers, Oxya spp.) was a popular food in the Fukushima area, before the reactor accident at Fukushima Dai-ichi Nuclear Power Station in March 2011. We investigated the radioactivity of Cs-134 and Cs-137 contained in Inago captured in Sukagawa, Motomiya, Inawashiro, Date, and Iidate in Fukushima prefecture in 2011 and 2012. The maximum combined radioactivity of Cs-134 and Cs-137 in Inago was 60.7 Bq/kg, which is below the maximum permitted level (100 Bq/kg) in foods established by the government of Japan in April 2012. Furthermore, conventional cooking processes decreased the radioactivity in cooked Inago to under 15.8 Bq/kg, a quarter of that in uncooked Inago. Therefore, we concluded that the health risk of eating Inago is low.