The Effects of Tocopherol Nanocapsules/Xanthan Gum Coatings on the Preservation of Fresh-Cut Apples: Evaluation of Phenol Metabolism

The aim of this study was to evaluate the effect of different xanthan gum coatings with nanoparticles (nanocapsules and nanospheres) on the production and oxidation of phenolic compounds generated by enzymatic activity (phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO)) on fresh-cut Red Delicious apples stored for 21 days at 4 °C. The nanoparticles were prepared using the emulsification-diffusion method. The film systems formed had particle sizes (Ps) of 190 to 260 nm, the polydispersity index (Pdi) was < 0.3+, and the zeta potential was (ζ) > |35| mV parameters that suggest good physical stability. While all the nanoparticulate coatings proved to be effective, the best coating was the nanocapsules/xanthan gum combination because it decreased the initial respiration rate by 63 % compared to controls. The effect on PPO and PAL activity was associated with the protection of phenolic compounds, whose concentrations remained unchanged. Also, lower variations in total color differences were found.