Nutritional profile of the wild harvested armoured cricket (Acanthoplus discoidalis) (Orthoptera: Tettigoniidae) in northern region of Zimbabwe

Armoured crickets are an important food source in some parts of Zimbabwe. These insects are abundant in some regions but however, they are under utilised and not much is known about their nutritional value. The aim of this study was to determine the nutritional profile of the armoured cricket (Acanthoplus discoidalis). Armoured crickets were collected from a structured sampling framework in Mbire district Mashonaland Central province of Zimbabwe. Removal of the head and thorax, degutting and boiling were done. A proximate analysis was carried out followed by mineral, amino acid and fatty acid profiling of the prepared insects. Analyses were done on a dry basis. A. discoidalis contained 69.2% protein, 16.8% fat, 8.6% ash, 1.2% carbohydrate, 4.2% chitin and 454.3 Kcal/100 g energy. A 100 g dry weight quantity of insect contains 11.48 mg iron which is enough to meet the required daily intake of 10.0-20 mg/day for an adult. The zinc (4.37 mg/100 g dry weight) and phosphorus (491.4 mg/100 g dry weight) content in A. discoidalis almost meets the reference nutrient intake for adults. Essential amino acids, leucine (60.7 mg/g protein) had the highest concentration followed by phenylalanine+tyrosine (59.3 mg/g protein), valine (48.4 mg/g protein), lysine (46.7 mg/g protein), threonine (37.4 mg/g protein), isoleucine (26.4 mg/g protein), methionine+cysteine (20.9 mg/g protein) and histidine (16.5 mg/g protein) the least concentration. In total, 9 saturated fatty acids were determined of which stearic acid and palmitic acid had the highest concentrations of 2,034.5 mg/100 g and 2,005.3 mg/100 g respectively. Four mono unsaturated fatty acids were determined of which oleic acid and palmitoleic acid had the highest concentrations of 361.4 mg/100 g and 305.2 mg/100 g respectively. Four poly- unsaturated fatty acids were determined of which eicosapentaenoic and a-linolenic acid had the highest concentrations of 1,598.0 mg/100 g and 185.6 mg/100 g respectively. A. discoidalis is good source of protein, the minerals iron, zinc and phosphorus, some essential amino acids and poly-unsaturated fatty acids.

Automated summary

Armoured crickets are an important food source in certain parts of Zimbabwe. However, their nutritional value is not well understood. This study aimed to determine the nutritional profile of armoured crickets and found that they are rich in protein, iron, zinc, phosphorus, essential amino acids, and polyunsaturated fatty acids.