Utilization of nutshell wastes in chitosan-based food packaging films

In the first part of this thesis, lignocellulosic compounds were obtained by alkaline extraction method for the utilization of hazelnut shell wastes. According to experimental design prepared with response surface method and Box-Behnken design, alkaline (NaOH) concentration (1, 6,5, and 12% w/v), extraction temperature (30, 65, and 100°C) and extraction time (30, 75, and 120 min) were selected as independent variables. For evaluation of extraction conditions, the fiber yield, percent hemicellulose, cellulose, and lignin, cellulose/hemicellulose, lignin/hemicellulose content and water absorption capacity were selected as (dependent) responses. According to the result of regression analysis, it was decided to maximize the fiber yield and the cellulose content. For this purpose, in optimization analysis; 1% NaOH, 100°C extraction temperatures and 30 min extraction time was selected by the model. At this optimum point alkaline extraction experiment analysis was performed. It was found that the extraction efficiency and cellulose % were in the same group as the results predicted by the model (p>0,05). In the second part of this thesis, the extracted hazelnut shell powder (EL) at the given optimum extraction condition or raw hazelnut shell powder (HL) was added into the biodegradable chitosan film as fillers. The film properties such as water vapor permeability, optical, mechanical and thermal properties, Fourier transform infrared spectra, antimicrobial properties and surface morphology of the films produced by adding HL or EL at a rate of 1, 5, 10 or 20% (on chitosan basis) were investigated. According to the results, film thicknesses and brightness value were increased with HL or EL filler addition. Besides, it was determined that 1% EL film had the lowest water vapor permeability and the highest thermal stability.