Effects of edible insect ingredients on the physicochemical and sensory properties of extruded rice products

Entomophagy, or the practice of consuming insects, can provide a nutritious relief to many malnourished people. Currently, two billion people from over 113 countries consume some 2,000 recorded edible insects as part of their traditional diets. Many of these insects contain adequate amounts of protein, fat, vitamins, and minerals that are comparable to commonly eaten livestock. Accordingly, the goal of this study was to investigate the feasibility of incorporating edible insect flours in an extruded rice product. Four formulations were developed, including cricket or locust flours at 10 or 15% addition levels, respectively. The extrusion was easier to proceed when making the two cricket formulations than making the two locust formulations. This could be attributed to higher fat content and lower dietary fibre in cricket flour, which may have enhanced the extrusion process to some extent. Nutritional analysis suggested these insect rice formulations are good sources of protein, fat, dietary fibre and iron. Physicochemical properties of the novel insect rice products were assessed against a reference, market brown rice. Overall, the insect rice was found to have darker colour than the reference and to be softer and stickier in texture after cooking. Sensory evaluations involving 120 untrained panellists suggested cricket formulations at 10% and 15% levels were well accepted based on colour, aroma, flavour and mouthfeel. Both cricket formulations warrant continuing optimisation, however, the 15% locust formulation was least preferred by the sensory panel. In conclusion, as a staple food providing 20% of the world's dietary energy and consumed by more than 1 billion people, rice is an ideal vehicle to deliver nutrients carried by edible insects. The incorporation of insect flours in processed foods such as extruded rice products can greatly promote the consumer acceptance by disguising the 'yuck' factor associated with intact insects.