Stored Grain Protection by Phytochemical Pulegone-Based Nano Emulsion

One of the most significant contributors to the global food crisis is grain losses during storage mainly caused by pest insects. Currently, there are two main methods used for stored product insect pest control: fumigation with very toxic gases and grain protection by residual contact insecticides. Today, the global tendency is to prevent/reduce the wide use of chemical insecticides, which have high toxicity to humans. Therefore, there is an urgent need to develop alternative eco-friendly approaches for stored insect pest control.

Plant essential oil constituent pulegone which is known as a very active against stored product insect pests, was encapsulated into coarse and nano emulsions. The prepared emulsions were characterized by spectroscopic and microscopic methods and their stability and pulegone release ability at various environmental conditions were examined. The insecticidal activity of the developed formulations against two stored product insects, rice weevil (Sitophilus oryzae L.) and red flour beetle (Tribolium castaneum Herbst) was demonstrated in laboratory and pilot experiments.

It was found that the pulegone-based nano emulsion formulation offered significant advantages and provided powerful and prolonged biological activity. The developed pulegone-based nano emulsions could serve as a natural, effective, low-toxify for human, and environmentally preferred method for protection stored grain and dry food products from pest insects.