The increasing global concern over plastic waste and its environmental impact has led to a growing interest in the development of sustainable packaging alternatives. This study focuses on the innovative use of expired dairy products as a potential resource for producing edible packaging materials. Expired dairy products, which are typically discarded, contribute to food waste and environmental pollution. By modifying these products to packaging materials, a dual-purpose solution addressing both waste reduction and sustainable packaging is evaluated. Expired milk and yogurt were selected as the primary raw materials due to their protein and carbohydrate content. The extracted casein was combined with various concentrations of chitosan while in some cases glycerol was used. The materials were characterized with attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray analysis (XRD) to examine the interactions between the components of the formed binary blend. Scanning electron microscopy (SEM) was used to evaluate the surface morphology of the blends, while dynamic mechanical analysis (DMA) and tensile experiments were conducted to study the thermomechanical properties of the materials. Barrier properties, including water vapor transmission (WVTR) and oxygen permeability (OTR), were measured to assess the materials' potential to preserve food freshness. The findings reveal that expired dairy-based edible packaging materials exhibit promising mechanical properties, comparable to conventional plastic packaging. The barrier properties and especially the zero oxygen permeability of the membranes, indicate that these materials have the potential to effectively protect food products from external factors that could compromise quality and shelf life. The materials show encouraging signs of eco-friendliness, with a notable reduction in environmental persistence compared to conventional plastic packaging.

Cellulose nanocrystals are of major research interest because of their use in biodegradable bioplastcs and food packaging, biomaterials, medical and pharmaceutical applications, cosmetics, electronics, and construction materials. This study introduces an approach combining microwave-assisted extraction (MAE) of cellulose from Aloe Vera plant residue and subsequent isolation of cellulose nanocrystals (CNCs) utilizing sulfuric acid hydrolysis. The MAE process, characterized by its rapid heating and penetrating ability, was optimized to maximize cellulose yield from raw biomass sources under various conditions (microwave power, solvent ratio, and time). Following extraction, the purified cellulose was subjected to sulfuric acid hydrolysis under controlled conditions to yield CNCs, with the aim of preserving the intrinsic crystalline structure while enhancing the material's physicochemical properties. The search for biocompatible and biodegradable materials suitable for biomedical applications has led to significant interest in hydrogels composed of natural polymers. Among these, hydrogels synthesized from cellulose and polyvinyl alcohol (PVA) have emerged as promising candidates due to their unique physical properties and compatibility with biological tissues. This study presents the formulation, characterization, and potential biomedical applications of a cellulose/PVA hydrogel. The hydrogel was synthesized to enable the formation of a semi-crystalline network that imparts the material with enhanced mechanical properties.

Nowadays bioeconomy and sustainability trend drive food technology in the development of novel biobased edible food preservatives to enhance food shelf-life and safety. This study explored the development, characterization, and application of novel polysaccharide-based nanogels enhanced with essential oil derivatives carvacrol and citral, investigating their potential synergistic effects as active edible coatings for extending the shelf life of Chalkidiki PDO green table olives. Nanogels were formulated using xanthan gum and kappa-carrageenan and tested in various ratios (25:75, 50:50, 75:25). Physicochemical characterization of nanogels was done via zeta potential dynamic light scattering measurements and scanning electron microscopy images, while preliminary tests demonstrated high antioxidant activity. Antimicrobial assessments revealed significant bactericidal effects, with FIC results confirming a synergistic effect of NGCTCV 50:50 against Staphylococcus aureus and NGCTCV 25:75 and 75:25 against. The nanogel coatings were applied to Chalkidiki green table olives and evaluated over a 21-day storage period. The NGCTCV 50:50 and 25:75 coatings effectively reduced weight loss, maintained stable pH levels, and preserved visual quality, while inhibiting spoilage microorganisms without affecting beneficial lactic acid bacteria crucial for fermentation. Lab colorimetry confirmed the ability of these nanogels to prevent discoloration, maintaining the olives' characteristic green color. Sensory analysis indicated that NGCTCV 50:50 and 25:75 outperformed both individual nanogels and uncoated samples, effectively extending shelf life by over 14 days. Finally, this study demonstrates the potential of polysaccharide-based nanogels, particularly in the 50:50 and 25:75 ratios, for improving the shelf life of perishable food products, with promising applications in fermented food preservation.