Effect of Homogenization Method and Carvacrol Content on Microstructural and Physical Properties of Chitosan-Based...

Area of Science:

• Food Science and Technology
• Materials Science
• Polymer Science

Background:

• Active edible films enhance food preservation by incorporating compounds like essential oils (EOs).
• Nanoemulsions of EOs in edible films offer controlled release and improved film properties.
• Chitosan-based films are promising for active packaging due to their film-forming and bioactive potential.

Purpose of the Study:

• To investigate the impact of homogenization methods and carvacrol concentration on the microstructure and physical characteristics of edible nanoemulsified chitosan films.
• To optimize the formulation and processing of active edible films for enhanced food preservation.
• To evaluate the relationship between film microstructure and functional properties.

Main Methods:

• Preparation of film-forming emulsions (FFE) using chitosan, Tween 80, and varying carvacrol concentrations (0.25%, 0.5%, 1.0%).
• Application of two homogenization techniques: rotor-stator and combined rotor-stator with high-pressure homogenization.
• Characterization of film microstructure using Scanning Electron Microscopy (SEM) and evaluation of physical properties (mechanical, optical, water vapor permeability).

Main Results:

• High-pressure homogenization significantly altered film microstructure, resulting in smaller and more homogeneously distributed carvacrol droplets, particularly at 0.5% carvacrol (1:1 Tween 80: carvacrol ratio).
• Films produced via high-pressure homogenization exhibited reduced opacity, increased elongation, and lower water vapor permeability compared to those made solely with the rotor-stator method.
• The optimized processing conditions led to substantial improvements in the overall physical and barrier properties of the active edible films.

Conclusions:

• High-pressure homogenization is an effective method for developing advanced edible nanoemulsified chitosan films with superior properties.
• The study demonstrates the potential of these active films for improving food preservation through enhanced mechanical resistance, transparency, and barrier functions.
• Optimizing carvacrol content and homogenization pressure is crucial for achieving desirable characteristics in active edible films for food applications.