Utilization of potassium carbonate-olive oil solutions for wax removal from fruits: Investigation of mode of action using a model gelatin-based film system

Abstract

This study evaluated a potassium carbonate-olive oil solution's efficacy in removing a wax from gelatin films (model surfaces). The solution (pH 12.15–12.40) was most effective with 1 % olive oil. Dipping treatment increased wax-free film thickness by 89 % and wax-containing films by 36 %, while reducing density by 50 % and 21 %, respectively. Optical analysis confirmed wax removal, showing a 20 % drop in whiteness and 144 % higher opacity in wax-containing films. Thermal analysis revealed a 35 % lower wax melting enthalpy and 28 % less mass loss in treated films. FTIR spectra showed reduced ester CO peak intensity (1735 cm⁻¹), confirming hydrolysis. Post-treatment, the solution's particle size grew to 2138 nm, zeta potential fell to 20.4 mV, and surface tension dropped to 40.94 mN/m. Microscopy revealed increased particle aggregation with wax-containing films. These results demonstrate the potassium carbonate-olive oil solution's effectiveness in wax removal from gelatin film surfaces through hydrolysis, emulsification, and solubilization mechanisms.