Evaluation of the antioxidant activity of aqueous and organic extracts of edible insects to different cooking temperatures and pH conditions

Resumen

Objective: To evaluate heat treatment and pH on the antioxidant activity of extracts obtained from edible insects endemic to Mexico. Insects known as jumiles, grasshoppers (adults and nymphs), red maguey (Agave sp.) wormfrom the maguey penca, white maguey worms from the pineapple, and chicatanas were used.

 Design/methodology/approach: Different solvents (water, methanol, ethanol, NaCl, and acetic acid) were used to prepare the extracts. These were characterized by X-ray diffraction, and the effect of temperature and pH on their antioxidant activity was analyzed. The methods used were DPPH and FRAP, and total polyphenols and flavonoids were quantified.

Results: There are presence of antioxidant molecules characterized as quercetin, hesperetin, and DL-α-lipoic acid. The extracts with the highest content of flavonoids and total phenols were from adult grasshoppers in water, chicatanas in 50% ethanol, and maguey worms from the penca in water. However, the antioxidant activity of these extracts was negatively affected by elevated pH and temperature.

Study limitations/implications: The main limitations of the study were the availability of the insects, which are endemic species of Mexico and most are seasonal.

Findings/conclusions: Molecules with antioxidant capacity were identified, and their antioxidant activity decreased when exposed to high pH values.