Frage Abookleesh | ALES Graduate Seminar

Event details: A graduate exam seminar is a presentation of the student’s final research project for their degree. This is an ALES PhD Final Exam Seminar by Frage Abookleesh. This seminar is open to the general public to attend.

Zoom Link: https://ualbertaca.zoom.us/j/91925548817?pwd=11KmI5Ft1DDSEuXhPkj6Y5RRXQNhWX.1

PhD with Dr. Aman Ullah.      

Thesis Topic: Approaches to the Development and Utilization of Rapeseed Protein-Based Bioplastics for Sustainable Food Packaging Applications

Abstract:

The increasing demand for sustainable and eco-friendly materials has intensified the search for viable alternatives to synthetic plastics, particularly in food packaging applications. This thesis explores the utilization and optimization of rapeseed protein as a promising biopolymer for developing bioplastics with enhanced mechanical, barrier, and functional properties. Given rapeseed protein’s inherent limitations, including weak mechanical performance and high hydrophilicity, a multi-faceted approach was employed to improve its properties through molecular docking, experimental optimization, and machine learning-driven predictive modeling.

Initially, molecular docking tools were utilized to systematically screen and rank 21 different additives, including plasticizers, cross-linkers, and biopolymer blending agents, based on their compatibility with rapeseed protein. This computational approach provided valuable insights into protein-additive interactions, enabling the selection of chitosan, citric acid, and glycerol as the most suitable additives. These selections were based on the strength of interactions, as determined by binding affinities and types of molecular interactions involved. The findings underscore molecular docking as a rapid, cost-effective, and reliable strategy for additive selection, significantly reducing the reliance on time-consuming experimental trials. While this method primarily facilitated the identification of highly compatible additives, it also holds potential for discovering new functional additives.

Experimental studies demonstrated the effectiveness of nano-reinforcement in enhancing rapeseed protein-based bioplastics. Cellulose nanocrystals (CNC), montmorillonite (MMT), and hydroxyapatite (HA) were incorporated as nanofillers. CNC exhibited superior performance, improving tensile strength, elongation, barrier properties, and thermal stability. These enhancements were attributed to strong hydrogen bonding and matrix stability. In contrast, HA and MMT showed limited effects due to aggregation hindering effective interaction. Further, hybrid biopolymer blends of rapeseed protein and chitosan were synthesized and dual-compatibilized using MMT and citric acid. This led to improved tensile strength, barrier, and thermal properties, demonstrating their viability for sustainable food packaging. Fourier-transform infrared (FTIR), X-ray diffraction (XRD), and morphological analyses confirmed the molecular interactions and compatibility of hybrid blends.

Machine learning addressed the complexity of optimizing bioplastic formulations. Limited experimental data were augmented through data generation processes, capturing nonlinear relationships between input variables (e.g., CNC concentration, gelatin ratio, citric acid levels) and output properties (e.g., tensile strength, elongation, water vapor permeability). Three machine learning models, Random Forest (RF), Gradient Boosting (GB), and Convolutional Neural Networks (CNN), were developed as multi-objective optimization tools. These models demonstrated high predictive accuracy, with R² values exceeding 0.95, successfully predicting optimal formulations. The most promising formulation achieved a tensile strength of 28.94 MPa, elongation of 22.61%, and water vapor permeability of 4.40 g mm/m² d kPa × 10², meeting high-performance food bio-packaging criteria.

Real-world validation showed the rapeseed protein-chitosan hybrid nanocomposite, dual-compatibilized using MMT and citric acid, exhibited strong mechanical properties, thermal stability, and biodegradability. Its application in blueberry packaging extended shelf life and maintained quality compared to synthetic films and unpacked controls. The hybrid film’s antioxidants, antimicrobial, and barrier properties reduced microbial spoilage, weight loss, and changes in key indicators such as firmness, antioxidant activity, and total soluble solids (TSS). Furthermore, the rapeseed-gelatin nanocomposite film preserved strawberries and pears, significantly reducing weight loss, enzymatic browning, and decay over a storage period of 7 days. These findings emphasize rapeseed protein’s potential to overcome existing bioplastic challenges, positioning it as a cost-effective, scalable alternative for sustainable food packaging. By addressing raw material availability, mechanical properties, and scalability, this work establishes rapeseed protein as a promising material for sustainable bioplastics, paving the way for eco-friendly food packaging solutions.