Eco-friendly technologies for obtaining antioxidant compounds and protein hydrolysates from edible insect Tenebrio molitor beetles

The functional properties of edible insects can be explored by a joint use of novel technologies. This work applied varied pre-treatments (ultra-sound-assisted extraction, UAE; microwave-assisted extraction, MAE; temperature-assisted extraction, TAE; CO2-assisted extraction) and solvents (water, ethanol, water:ethanol) in Tenebrio molitor beetles to enhance the extraction of phenolic compounds with antioxidant activity. An enzymatic hydrolysis (EH) was performed in wet and treated biomasses to determine the protein hydrolysis. Higher phenolic compounds and antioxidant activity was released after MAE using water as solvent compared to the other treatments and solvents. Treatments decreased 32 %, 19 % and 30 % the protein, chitin and lipids content. EH improved protein and amino acids hydrolysis in the MAE-treated insects, followed by UAE and TAE treatments. In conclusion, MAE was the most effective to release phenolics and antioxidant activity from T. molitor beetles, while using MAE followed by EH improved protein and amino acids hydrolysis, envisioning valuable applications for this insect biomass.