Chemical composition, thermal profile and functional properties of grasshopper (Sphenarium purpurascens Ch.), cockroach (Nauphoeta cinerea) flours and their mixtures

Abstract

The use of insects as food is a hot topic today and the obtaining and comprehensive characterisation of insect meals is relevant since any scientific information represents progress towards the real use of these ‘new foods’. Therefore, the objective of this study was to evaluate the chemical composition of flours obtained from Sphenarium purpurascens Ch. and Nauphoeta cinerea, identify the main components and know their functional properties and thermal profile in flours and their mixtures to establish their potential applications as ingredients in the food and feed industry. The results revealed that flours and their mixtures can be used to increase the nutritional value of foods, especially thanks to their high protein content (35%–38%); in addition, their potential uses are numerous and range from baking, snacks, drinks and meat substitutes thanks to their techno-functional and thermal properties. Regarding the thermal profile, this study presents results above 250 °C that have not been reported before for these insects and relate to the decomposition of acetylglucosamine units and the evaporation of low molecular weight volatile products that have not been reported for the flours of these insects. This study represents an advance in terms of the use of insects, pending attention to issues such as innocuity.