title: Formulating essential oil microemulsions as washing solutions for organic fresh produce production.
abstract: Applications of plant-derived organic essential oils (EOs) as antimicrobials for post-harvest produce operations are limited by their low water solubility. To dissolve EOs in water, microemulsions were studied using two surfactants permitted for organic production, sucrose octanoate ester (SOE) and soy lecithin that were mixed at various mass ratios before dilution with water to 40% w/w. EOs were then mixed with the surfactant solution by hand shaking. Based on visual transparency, intermediate lecithin:SOE mass ratios favoured the formation of microemulsions, e.g., up to 4.0% clove bud oil at ratios of 2:8 and 3:7, and 4.0% cinnamon bark oil and 3.0% thyme oil at ratios of 2:8 and 1:9, respectively. Microemulsions with intermediate lecithin:SOE mass ratios had a relatively low viscosity and better ability to wet fresh produce surfaces. The microemulsions established in this work may be used as washing solutions to enhance the microbial safety of organic fresh produce.
authors.affiliation: Department of Food Science and Technology, The University of Tennessee, Knoxville, TN, United States.
authors.forename: Linhan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Food Science and Technology, The University of Tennessee, Knoxville, TN, United States.
authors.forename: Faith
authors.initials: F
authors.lastname: Critzer
authors.affiliation: Department of Food Science and Technology, The University of Tennessee, Knoxville, TN, United States.
authors.forename: P Michael
authors.initials: PM
authors.lastname: Davidson
authors.affiliation: Department of Food Science and Technology, The University of Tennessee, Knoxville, TN, United States. Electronic address: qzhong@utk.edu.
authors.forename: Qixin
authors.initials: Q
authors.lastname: Zhong
mesh_terms: D002626:Chemistry, Pharmaceutical; D004655:Emulsions / Q000032:analysis*; D058870:Food, Organic / Q000032:analysis*; D009822:Oils, Volatile / Q000737:chemistry*; D010938:Plant Oils
chemical_list: D004655:Emulsions; D009822:Oils, Volatile; D010938:Plant Oils
keywords: Contact angle; Essential oil; Microemulsion; Organic fresh produce; Surfactant blend; Washing solution