ACCELLERATED SELF-LIFE TESTING OF COFFEE: THE ROLE OF INNOVATIVE FLEXIBLE PACKAGING MATERIALS ON OXIDATION AND SHELF-LIFE ESTIMATION WITH A SIGHT ON THEIR ENVIRONMENTAL SUSTAINABILITY.

The preservation of roasted and ground coffee quality during storage represents a critical challenge for the food packaging industry. Coffee's unique sensory and chemical profile is highly sensitive to environmental conditions, including oxygen, humidity, and temperature. These factors accelerate degradation processes, such as oxidation, leading to a decline in aroma, flavour, and shelf life. The development of effective, sustainable, and high-performance packaging solutions requires a multidisciplinary approach that combines material science, analytical techniques, sensory evaluation, and environmental sustainability. This dissertation addressed these challenges by exploring innovative solutions across five interconnected studies, providing actionable insights for the coffee packaging industry. The research began with an in-depth analysis of gas and moisture permeation in polyolefin-based packaging structures. Seven flexible formats, incorporating ethylene vinyl alcohol (EVOH) and metallized polypropylene barrier layers, were evaluated under varying temperature and relative humidity conditions. The findings revealed that EVOH-based materials are more sensitive to environmental changes due to their hydrophilic nature, while metallized structures exhibited superior stability. The positioning of the barrier layer within multilayer architectures was optimized using response surface methodology, achieving a minimal layer distance of 58 µm for optimal oxygen permeability under high-stress conditions. These insights were applied to estimate the two-year shelf life of coffee packages, identifying metallized and select EVOH-based materials as the most effective solutions. The second focus of this work involved the evaluation of advanced analytical techniques such as electronic nose (e-nose), gas chromatography-mass spectrometry (GC-MS), and Fourier-transform near-infrared (FT-NIR) spectroscopy, for monitoring coffee aging. These methods were combined with sensory analysis to investigate the evolution of coffee quality under adverse conditions. Sensory evaluation confirmed a decline in attributes such as aroma intensity and aftertaste, accompanied by increases in bitterness and oxidation-related characteristics. Analytical techniques identified key markers of degradation, including volatile organic compounds (VOCs) and chemical changes in oily compounds and carbohydrates. Integrating these data with principal component analysis (PCA) provided a comprehensive understanding of coffee quality evolution during storage. Oxidation was further investigated through a study on the impact of high oxygen concentrations and varying storage temperatures. Results demonstrated that oxygen consumption and sensory oxidation attributes follow distinct thermal sensitivities, with oxidation thresholds ranging from 330 µg to 430 µg of oxygen per gram of coffee. These findings enhance the ability to predict shelf life and optimize packaging solutions under real-world conditions. The final component of the research examines the environmental impact of coffee packaging structures using Life Cycle Assessment (LCA). Comparing traditional aluminium-based materials with recyclable mono-materials, the study revealed that metallized recyclable packaging offers the best balance between barrier performance and sustainability. The results advocated for reducing raw material use and increasing recycling rates to align with circular economy principles. By integrating material performance, analytical monitoring, sensory evaluation, and sustainability assessments, this dissertation provided a holistic framework for addressing the complex demands of coffee packaging. The findings contributed to the development of innovative, efficient, and environmentally responsible packaging solutions, meeting the dual objectives of preserving coffee quality and reducing environmental impact. This work underscored the importance of multidisciplinary strategies in advancing food packaging technologies and supporting the global transition toward sustainable practices.