Effect of extraction parameters (defatting, solvent type, solvent concentration, sonication time and processing method) on total phenolics’ of the edible long-horned grasshopper Ruspolia differens

Abstract

This study aimed at determining the effect of extraction parameters (defatting, solvent type, solvent concentration, sonication time and processing method) on total phenolic content in Ruspolia differens (edible grasshoppers) in Uganda. The Folch method was used during the defatting process, three solvents, ethanol, methanol and acetone each at different concentrations (50%, 75% and 100%) were used in the extraction of Total Phenolic Content using different sonication time of 15, 30, 45 or 60 minutes for both the defatted and raw samples of R. differens while Total Phenolic Content was determined using Folin Ciocalteu’s reagent method.

The highest Total Phenolic Content obtained in the grasshopper was 0.066 mg GAE/ml from the raw sample using Acetone as the solvent, with the concentration of 100% at 45 minutes sonication time. Pan frying as a method of processing resulted in the highest total phenolic content obtained from a raw sample of 0.065 mg GAE/ml while all other processing methods significantly increased the total phenolic content especially in raw samples whereas defatted samples gave lower total phenolic content.