Citral Chemotype of Pectis elongata Essential Oil: Nanoemulsification and Enhanced Antimicrobial Properties for Food Safety
Lais T. Massing
Laboratório de Bioprospecção e Biologia Experimental, Universidade Federal do Oeste do Pará, 68035-110 Santarém, PA, Brazil.
Rosa Helena V. Mourão
Laboratório de Bioprospecção e Biologia Experimental, Universidade Federal do Oeste do Pará, 68035-110 Santarém, PA, Brazil and Programa de Pós-Graduação em Biodiversidade e Biotecnologia da Amazônia Legal (Bionorte), Universidade Federal do Oeste do Pará, 68035-110 Santarém, PA, Brazil.
Sandra Layse F. Sarrazin
Laboratório de Bioprospecção e Biologia Experimental, Universidade Federal do Oeste do Pará, 68035-110 Santarém, PA, Brazil.
Chieno Suemitsu
Laboratório de Bioprospecção e Biologia Experimental, Universidade Federal do Oeste do Pará, 68035-110 Santarém, PA, Brazil.
Pablo Luis B. Figueiredo
Departamento de Ciências Naturais, Centro de Ciência Sociais e Educação, Universidade do Estado do Pará, Belém 66050-540, Brazil and Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Pará, 66075-110 Belém, PA, Brazil.
Caio P. Fernandes
Laboratório de Nanobiotecnologia Fitofarmacêutica, Universidade Federal do Amapá, 68903-014 Macapá, AP, Brazil.
José Guilherme S. Maia *
Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Pará, 66075-110 Belém, PA, Brazil.
*Author to whom correspondence should be addressed.
Abstract
Aims: Essential oils of Pectis elongata from the Brazilian Amazon were analyzed to estimate the citral (neral and geranial stereoisomers) content in the vegetative and reproductive phases and their circadian cycle. Also, a nanoemulsification bioassay was performed to determine its impact on the oil composition and antimicrobial effectiveness against food contaminant agents.
Methodology: Gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GC-MS) analyzed the oil composition, nanoemulsion, and the citral standard. Nanoemulsion was prepared using low-energy input methodology with phase inversion, and its mean diameter, polydispersity index, and volatile composition were evaluated on the 1st, 7th, and 15th-day post-processing.
Results: The citral content of P. elongata oil ranged from 70.0% to 92.5% in the performed studies. The disk diffusion and minimum inhibitory concentration bioassays conducted with the emulsified essential oil exhibited antimicrobial activity that was two to four times greater than the oil itself, with this nanoemulsion showing an average diameter between 140.7 ± 6.79 and 177.07 ± 9.24 nm, a polydispersity index between 0.36 and 0.47 ± 0.09, and a zeta potential between -2.54 ± 2.6 and -7.25 ± 2.37.
Conclusion: Citral was maintained as the oil main constituent, preserving its biological properties and significantly enhancing its antimicrobial activity against various pathogenic agents contaminating and spoiling food. These findings highlight the potential application of a citral-rich oil nanoemulsion to enhance food safety.
Keywords: Essential oil composition, citral (neral and geranial stereoisomers), seasonal and circadian evaluation, oil nanoemulsification, antimicrobial activity