A new economical route for the grapefruit peel essential oil: Nanoemulsion form and insecticidal activity

The essential oil (EO) extraction is one of the ways to utilize of grapefruit (Citrus paradisi L.) peel waste. However, the low stability and penetration problems of EO limit their use. These limitations can be overcome by nanoemulsions. Therefore, this study aimed to form and characterize of the grapefruit peel essential oil nanoemulsion (EO--N) and investigate its insecticidal properties against Sitophilus granarius (Linnaeus, 1875) and Tribolium castaneum (Herbst, 1797) for an alternative bio-economic way. The grapefruit peel EO--N (4:3:3:90 w/w, EO:Tween 80:Ethanol:water) was formed by using the grapefruit peel EO with major chemical components such as d-limonene (85.70 %), myrcene (3.57 %), a-pinene (1.17 %). The grapefruit peel EO--N was characterized by TEM (50-120 nm), Zeta sizer (the mean droplet particle size: 109.3 nm, z -potential value:-20.6 mV, polydispersity index:0.265) and FT-IR analysis. 500 ppm of the grapefruit peel EO--N caused 50 % and 20 % mortality in S. granarius and T. castaneum after 7 days, respectively. 1000 ppm of the grapefruit peel EO--N caused 85 % and 50 % mortality in S. granarius and T. castaneum after 7 days, respectively. Based on the findings, the grapefruit peel EO--N may be considered having the potential to integrate management strategies for these pests and open a new bio-economic way. (c) 2024 SAAB. Published by Elsevier B.V. All rights reserved.