Edible Insects


The consumption of insects in the tropical and sub-tropical regions has been extensively studied (van Huis, 2016). Representatives from various insect groups are consumed in these regions. Insect-eating habits are not only associated with nutritional aspects but also closely related to socio-cultural practices and religious beliefs in the region. Edible insects are also used to complement diets when other protein sources are not available during certain times of the year. In some regions, certain insect species are even considered as delicacies (van Huis, 2016). While insects have never been considered as a food source in Western countries, for today’s consumers who looking for nutrient-rich and ecologically sustainable sources for food, edible insects can be a perfect candidate (Klein, 2019; Owoeye, 2020). However, in order to gain deeper inroads, insect producers need to overcome the deep-rooted aversion to insects that is prevalent among Western consumers.

Figure: Cricket Flour

The global market for edible insects is expected to reach approximately USD 8 billion by 2030 (Globe Newswire, 2019). As of 2017, crickets (house cricket and field cricket) occupy the largest share of the global edible insect market. The other categories include mealworms (super worm, yellow mealworm, lesser mealworm), grasshoppers, ants, and silkworms.

The nutritional composition among different edible insect species is highly diverse. Various factors like the quality of their substrates, the developmental stage of harvesting, and environmental factors can all affect the nutrient content of edible insects (Finke and Oonincx, 2014; Payne et al., 2016). Apart from nutritional content, the quality of nutrients present in insects is also an important consideration.

Oibiokpa et al. (2018) analyzed the protein quality of four edible insects in Nigeria – field cricket (Gryllus assimilis), grasshopper (Melanoplus foedus), termite (Macrotermes nigeriensis) and moth caterpillar (Cirina forda). While all four insect species were found to have high protein content, crickets were determined to have a higher protein quality and digestibility (measured as protein digestibility-corrected amino acid score or PDCAAS4) as compared to the others (Oibiokpa et al., 2018).
PDCAAS provides an assessment of how well the dietary protein intake matches the body’s requirement for amino acids (FAO and WHO, 1991). 

FLAME RETARDANTS: Gaylor, Harvey and Hale (2012) reported bioaccumulation of polybrominated diphenyl ether (PBDE) from polyurethane foams, commonly found in consumer goods, in house crickets (Acheta domesticus). Tributylphosphate has also been identified in edible insect samples from Belgium (Poma et al., 2017). Feeding experiments show that mealworms rapidly excrete hexabromocyclododecane (HBCD) in their frass (Brandon et al., 2020). Poma et al. (2019) found low levels of contamination (within legal limits in food of animal origin) by various organic compounds (persistent organic pollutants, halogenated flame retardants, organophosphorus flame retardants, and plasticizers) in edible insects. 

These insects belonged to six orders (Orthoptera, Coleoptera, Lepidoptera, Hemiptera, Odonata, and Hymenoptera), and were purchased from five European and three Asian countries. The study also emphasized that, apart from activities during the period of rearing the insects, industrial post-harvest handling and the addition of various ingredients (flavours, dressings, among others) play a role in influencing the chemical load of the final insect food product (Poma et al., 2019).

A new preclinical study concludes that cricket powder provides distinctive antioxidant properties in addition to excellent nutrition, making it an innovative tool to be used in both food and medical fields. Researchers in Poland argued that most studies on crickets' nutritive values were done on lab-grown varieties, so they sought out the nutrition content of commercially available cricket powders. They found from three randomly selected samples on the market that cricket powders "contained a significant amount of protein, fat, fiber, and minerals." The researchers, affiliated with the Poznan University of Life Sciences and the Medical University of Lublin, tested three unnamed samples of cricket powders online.

Two of the products came from crickets raised in Thailand, while the third came from crickets raised in Canada. All were advertised as supplements and were available on the English market. "They may become a valuable food ingredient for different food products," they reported in their study, published in the journal Food Chemistry. Additionally, the researchers wrote that the high mineral content of cricket powder could make it an additive in products targeted at people suffering from celiac disease. Because many minerals are fortified into wheat products, "this group of consumers is especially vulnerable in terms of proper diet balance including an adequate supply of minerals," they wrote, referencing a 2018 study published in Nutrients.

Nutritional values
The researchers studied the cricket powders' nutritional values using a variety of methods including chemical assays, enzymatic methods, and spectroscopy. Protein was the dominant constituent for all the powders, ranging from 42% to 45.8% across all samples. The second dominant constituent was fat, which ranged from 23.6% of total weight in the sample with the least fat to 29.1% in the sample with the most fat. For carbohydrates, the researchers noted that dietary fiber ranged between 2.9% to 6.4% across samples.

For mineral content, they found that in 100 g of the products: the calcium content was 139-218 mg, potassium 826-1224 mg, magnesium 86-113 mg, sodium 263-312 mg, copper 2.33- 4.51 mg, iron 4.06-5.99 mg, managnese 4.1-12.5mg and zinc 12.8-21.8 mg

Proximate composition of crickets depends on its origin, stage of life, sex and feed, they explained.
For example, crickets are richest in fat during the larval stage. "This results in diversified nutritional value of cricket powders," according to the researchers.

Source: Food Chemistry


Nutritional value, protein and peptide composition of edible cricket powders Authors: Magdalena Montowska, et