The use of natural raw substances for food preservation could provide a great contribution to food waste reducing, circular economy enhancing, and green processes application widening. Recent studies indicated that natural preservatives release kinetics significantly influenced the food preservation process. The use of porous materials as absorber for natural essential oils provided nanohybrids with excellent antioxidant and antimicrobial properties. In this study the well-known SBA-15 porous material was used to control the release of the natural preservative thyme oil on food surface and to extend the food shelf-life. Results indicated that the thyme oil loading was higher than other porous materials reported recently and the addition of SBA-15 to the LDPE increases the water/oxygen barrier. The film with the higher thyme-oil@SBA-15 nanohybrid content exhibited the slower release kinetic. The antioxidant activity of the final films ignited after 48 hours, was in the range of 60-70%, and was almost constant for 7 days. Finally, all tests indicated a sufficient improvement by the addition of thyme-oil@SBA-15 nanohybrids in the pure LDPE matrix and the concentration of wt. 10% of such nanocarriers provided the optimum final LDPE/10TEO@SBE-15 active packaging film. This material could be a potential future product for active packaging applications.

Carvacrol is well-documented for its antibacterial and antioxidant effects. However, its high volatility has directed researchers towards nanoencapsulation technology according to bioeconomy and sustainability trends. This study examined and compared carvacrol microemulsion (MC), carvacrol microemulsion busted with chitosan (MMC) and carvacrol nanoemulsions as active coatings on extending minced pork meat shelf-life at 4±1 oC for 9 days, focusing on microbiological, physiochemical, and sensory characteristics. The research involved pre-characterizing droplet sizes, evaluating antioxidant, and determining antibacterial efficacy. The results demonstrated that NC with a 21 nm droplet size exhibited the highest antioxidant and antibacterial activity. All coatings succeed to extend the preservation of fresh minced pork meat in comparison to free carvacrol sample (FC). NC coating showed the highest extension of minced pork meat preservation and maintained meat freshness for 9 days, with a lower TBARs of 0.736 mg MDA/Kg, and effectively reduced mesophilic, lactic acid, and psychrotrophic bacterial counts more significantly 1.2, 2, and 1.3 log respectively as compared to FC. Sensory assessments confirmed the acceptability of NC and MCC coatings. Overall, the carvacrol based nanoemulsion can be considered as novel antioxidant and antimicrobial active coating due to its demonstrated higher efficacy in all the examined tests performed.

Biomass and biowaste valorisation is of major interest nowadays because of the spirit of circular economy and of the neutral environmental fingerprint global target. In the current project chondroitin sulphate (ChS) was incorporated with the crustaceous’ and shrimp’s byproduct chitosan (Chi) and the fish industry byproduct gelatine (FG) to obtain dense hydrogel membranes. Glycerol (Gly) was utilized to avoid brittleness. The formation of the hydrogel membranes is attributed to secondary interactions between the natural polymers and the plasticizer. The prepared hydrogel membranes were characterized by Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The surface morphology of the membranes was examined using scanning electron microscopy (SEM). Dynamic mechanical analysis (DMA) and tensile tests were also performed to evaluate the mechanical response of the membranes. The samples were also evaluated for membrane wettability, degradation rate and water vapor transmission rate (WVTR). Finally, in vitro endothelial cell attachment on the membrane were addressed. The overall results of the study indicate that the hydrogel membranes could be appropriate for external application in wound healing applications as dressings.

Today, enhancing food preservation and safety in the spirit of the bioeconomy suggests the use of biodegradable polymers such as poly-L-lactic acid (PLA) in food packaging and the replacement of chemical additives with natural antioxidant/antibacterial agents such as essential oils and their derivatives. Herein a novel carvacrol (CV) @ natural zeolite (NZ) nanohybrid was developed by employing a new vacuum adsorption desorption method which results in the adsorption of a high CV amount on NZ equal to 61.7 %wt. This CV@NZ nanohybrid was successfully dispersed in a PLA/triethyl citrate (TEC) matrix via a melt-extrusion process to obtain PLA/TEC/xCV@NZ nanocomposite films with 5, 10 and 15 CV@NZ %wt. content. PLA/TEC/xNZ films were also de-veloped for comparison. The overall study resulted in a biodegradable active film with the fol-lowing properties: 10%wt. CV@NZ content (PLA/TEC/10CV@NZ), self-healable properties, 22% higher tensile strength and 40% higher elongation at break, 45% higher water barrier and 40% higher oxygen barrier than pure PLA/TEC matrix. This film also provides high CV release content, high CV control release rate as well as significant antioxidant activity and antibacterial activity against the food pathogens Staphylococcus aureus and Salmonella enterica spp. enterica serovar Typhimurium. This film not only succeeds in extending the shelf-life of fresh pork minced, as shown by total variable count measurements in four days, but also prevents lipid oxidation of fresh minced pork and maintains the minced meat in higher nutritional conditions, as revealed by the heme iron content determination, and in a much better and acceptable sensory condition than the commercial packaging paper.

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.