Dynamics in nutrients, sterols and total flavonoid content during processing of the edible Long-Horned grasshopper (Ruspolia differens Serville) for food

Abstract

Long-horned grasshopper (Ruspolia differens Serville) is a tasty delicacy in over 20 African countries. This study evaluated the impact of diverse post-harvest thermal treatment (blanching, boiling, toasting, and deep-frying) on the nutrients, total flavonoid content and sterols preservation of R. differens products. Crude protein, ash, and fibre of R. differens was drastically reduced by deep-frying technique. There was increase in Omega-3 (α-linolenic acid), Omega-6 fatty acid (linoleic and arachidonic acids) and sterols [(22Z)-27-Norergosta-5,22-dien-3β-ol, cholesterol, campesterol, cholest-4-ene-3-one and β-sitosterol] and flavonoids (2-3 folds) during blanching compared to other techniques. The iron and zinc content increased significantly in blanched and boiled products of R. differens. Thus, losses of nutrients, total flavonoid content and sterols during processing of R. differens for food can be mitigated by employing blanching technique, which is cheaper and least time-consuming. The implications of these dietary and therapeutic compounds on human nutrition and health are discussed.

Keywords: Food and nutritional security; Nutrients; Post-harvest processing; Ruspolia differens; Sterols; Tettigoniidae; Total flavonoid.