Development of Edible Packaging for Selected Food Processing Applications

Edible packaging (coatings and films) has been used to improve the shelf life, sensory attributes and nutritional content of food products. The manufacturing process for edible packaging depends on the properties of the ingredients and the application end use. The objective of this study was to optimize the method for commercial-scale chitosan film production. This was done by optimizing the raw ingredient selection, and blending sequence. Quality control tests were used to monitor these include viscosity, the drying rate of the ingredient slurries, film solubility, chemical compositions, as well as the thermal properties of the edible films made during the study.;The first part of this dissertation (Chapter 2) focuses on the effects of solvents on the film properties. Edible slurries were prepared by dissolving 1.0-2.0% chitosan in 1.0% food-grade acetic or lactic acids with 0-20% ethanol solutions. Viscosities of the different film formulations were measured using a viscometer, and changes in drying time were determined using a OHAUS Moisture Determination Balance. Solubility of the films was determined by dissolving the dried films in water then measuring the weight changes. The chemical compositions of the polymeric chains were identified by Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterize changes to the thermal properties of the films as a result of the various treatments. Results indicated that viscosity of the slurries significantly (p < 0.05) increased with increasing chitosan and ethanol concentrations. ATR-FTIR spectra showed that acetic acid/chitosan provided more carboxyl (1442 cm-1) and amine groups (1573 cm-1) within the polymeric network when compared to the lactic acid/chitosan films. The addition of 20% ethanol significantly (p< 0.05) enhanced the drying rate of the film by 30%. However, additional ethanol did not have a significant influence on the solubility and thermal properties of the films.;The second part of this dissertation (Chapter 3 and Chapter 4) reports two methods for incorporating vitamin E into the chitosan. Edible chitosan slurries were prepared by blending 250 or 500 mg vitamin E into1.0- 2.0% chitosan. Two blending processes were used to incorporate the vitamin E into the edible slurries: (1) the vitamin E added before lecithin (VE first); and (2) the vitamin E mixed with lecithin (VE mixed) and then added into the slurries. Viscosities of the various formulations, thermal properties, the chemical compositions and solubilities of the film samples were done as mentioned before. High performance liquid chromotagraphy (HPLC) was used to determine the concentration of vitamin E in the films.;This study found that vitamin E addition significantly (p< 0.05) affected the rheology of the edible slurries. In addition, viscosity increased with increasing chitosan and vitamin E concentrations. Low chitosan concentrations in the formulation decreased vitamin E incorporating ability, leading to more vitamin E accumulation on the film surface. Solubility decreased with increasing accumulated vitamin E on the film surface. Results also showed that 2.0% chitosan blending with 500 mg VE was superior to the other formulations. More than 73% (368.60± 12.40 mg) of the vitamin E was successfully incorporated in the film. TGA analysis indicated that vitamin E decomposition occurred at 430-450°C. However, DSC thermograms showed no significant difference in glass transition temperature (Tg) and the phase changes in the films.