Edible packaging is an innovative method to address the problem emerged by petroleum based materials due to their non-toxicity and safety to improve quality by controlling microbial growth (Majumder and Balange 2023). Hydroxypropyl methylcellulose (HPMC) is a cellulose derivative which is used as packaging material due to biocompatibility, odorless and tasteless compound without affecting the fish organoleptic characteristics (Athanasopoulou et al. 2024). The aim of the study was to synthesize HPMC films with the best properties for preservation of gilthead seabream fillets.
2% HPMC-based films were produced according to the solvent casting method and glycerol was tested as a hydrophilic plasticizer while oleic and linoleic acid were used for their hydrophobic nature. Water barriers, hydrophobicity, mechanical, optical, and morphological properties, were evaluated HPMC-based films were applied on gilthead seabream fillets (Sparus aurata) stored isothermally at 4°C for shelf-life evaluation, based on Total Viable Count (TVC) and Pseudomonas spp. growth and compared with the respective data obtained for conventional polyvinyl chloride (PVC) films.
Moisture content showed that by adding hydrophobic materials used as plasticizers showed lower moisture content (8.49±0.26% and 13.42±1.91% when used linoleic and oleic acid, respectively), while moisture content was 77.26±2.75% for films with glycerol. All films showed high values of lightness and opacity. The replacement of conventional PVC films with the developed HPMC-based films did not affect the microbial growth of gilthead seabream fillets during refrigerated storage, resulting at shelf-life of 10 days at 4°C (same for all the tested conventional and alternative packaging films).
The results of the study show the potential of HPMC-based films for the effective preservation of chilled gilthead seabream, without affecting quality and shelf-life. The appropriate design of HPMC films and the selection of appropriate plasticizer for the desirable physicochemical properties of the developed packaging systems will contribute to the sustainability of the aquaculture sector towards a zero-waste future.
References
Athanasopoulou E, Bigi F, Maurizzi E, et al (2024) Synthesis and characterization of polysaccharide- and protein-based edible films and application as packaging materials for fresh fish fillets. Sci Rep 14:517. https://doi.org/10.1038/s41598-024-51163-y
Majumder RK, Balange AK (eds) (2023) Advances in fish processing technologies: preservation, waste utilization, and safety assurance, First edition. Apple Academic Press ; CRC Press, Palm Bay, FL : Boca Raton, FL