Essential Oils and Their Nanoemulsions as Lemon Bioconservators Against Penicillium spp.: An Integrated In Vitro, In Vivo, and In Silico Evaluation.

Abstract

This study aimed to evaluate the efficacy of essential oils (EOs) and their nano-emulsions (NEs) as natural alternatives for managing post-harvest blue mold in lemons, with specific focus on their antifungal properties and possible practical application. Essential oils were extracted from Pimpinella anisum (PEO) with a yield of 2.7% and Saccocalyx satureioides (SEO) with a yield of 2%. Nano-emulsions were successfully formulated; SNEO exhibited a mean particle size of 111.8 nm and a zeta potential of -45.6 mV, while PNEO had a size of 263.6 nm and a zeta potential of -33.3 mV, both demonstrating good kinetic stability. Biological activity assessments revealed significant findings. The in vitro antifungal tests against Penicillium italicum, nano-emulsions showed superior activity, with PNEO demonstrating an inhibition diameter of 33 mm compared to 15 mm for neat PEO. Similarly, MIC values against P. italicum were significantly lower for nano-emulsions (0.0781% v/v for both PNEO and SNEO) compared to their neat essential oil counterparts (0.1562% v/v). For antioxidant activity, SEO and SNEO exhibited strong DPPH radical inhibition, with IC50 values of 3.45% and 3.11% respectively, whereas PEO and PNEO showed a very weak activity. In vivo application on lemons demonstrated that SNEO and SEO maintained superior preservative capabilities over 21 days.