Optimization of the Physical, Optical and Mechanical Properties of Composite Edible Films of Gelatin, Whey Protein and Chitosan

Abstract

The aim of this work was to evaluate the effect of the concentration of gelatin (G) (3–6 g), whey protein (W) (2.5–7.5 g) and chitosan (C) (0.5–2.5 g) on the physical, optical and mechanical properties of composite edible films (CEFs) using the response surface methodology (RSM), as well as optimizing the formulation for the packaging of foods. The results of the study were evaluated via first- and second-order multiple regression analysis to obtain the determination coefficient values with a good fit (R ˃ 0.90) for each of the response variables, except for the values of solubility and b*. The individual linear effect of the independent variables (the concentrations of gelatin, whey protein and chitosan) significantly affected (p ≤ 0.05) the water vapor permeability (WVP), strength and solubility of the edible films. The WVP of the edible films varied from 0.90 to 1.62 × 10−11 g.m/Pa.s.m2, the resistance to traction varied from 0.47 MPa to 3.03 MPa and the solubility varied from 51.06% to 87%. The optimized values indicated that the CEF prepared with a quantity of 4 g, 5 g and 3 g of gelatin, whey protein and chitosan, respectively, provided the CEF with a smooth, continuous and transparent surface, with L values that resulted in a light-yellow hue, a lower WVP, a maximum strength (resistance to traction) and a lower solubility. The results revealed that the optimized formulation of the CEF of G–W–C allowed a good validation of the prediction model and could be applied, in an effective manner, to the food packaging industry, which could help in mitigating the environmental issues associated with synthetic packaging materials.

The Influence of the Structure of Selected Polymers on Their Properties and Food-Related Applications

“…The effects of protein type [ 60 ] as well as novel technologies used for film development [ 61 ] on the physicochemical, mechanical, and antioxidant properties of the resulting films are described in the literature. These properties can be also significantly improved using additives (such as plasticisers, nanoparticles of metals, metal oxides, or clay [ 62 ]) as well as when mixtures of different biopolymers are used, e.g., gelatine, whey protein, and chitosan composites [ 63 ]. A novel direction is the incorporation of active compounds such as phytochemicals further improving properties of protein-based coatings, e.g., increasing their antioxidant properties [ 64 ].…”

Recent Advances in Bio-Based Smart Active Packaging Materials

“…Chitosan is synthesised by the deacetylation of chitin, the only positively charged alkaline polysaccharide in nature [ 36 , 37 , 38 ]. It is nontoxic and odourless and can undergo chemical reactions such as oxidation, reduction, nitration, carboxymethylation and hydrolysis under the corresponding conditions to produce various chitosan derivatives with different properties.…”

Aloe vera/Chitosan-Based Edible Film with Enhanced Antioxidant, Antimicrobial, Thermal, and Barrier Properties for Sustainable Food Preservation

“…Several materials have been characterized for their film-forming abilities, including lipids (waxes or oils), proteins (gelatin or whey protein), biopolymers (alginate or chitosan), and carbohydrates (starches or cellulose derivatives) [ 4 , 5 , 6 ]. Each material has a unique composition and function [ 7 ].…”