Biodegradable coating based on chitosan and sea buckthorn for fish fillet preservation

This study investigates the effectiveness of a chitosan-based edible coating enriched with sea buckthorn (Hippophae rhamnoides L.) oil (HrEO) in extending the shelf life and preserving the quality of refrigerated fish fillets. In line with the increasing interest in natural preservation strategies, HrEO—characterized by its high antioxidant capacity—was incorporated into a chitosan (Ch) matrix to develop a bioactive coating formulation. The coated fillets were stored at + 4 °C, and their quality was assessed over 12 days through microbiological (total aerobic mesophilic bacteria, lactic acid bacteria, psychrotrophic bacteria, yeast–mold, Enterobacteriaceae), chemical (TVB‑N, TBA, pH), and sensory analyses. The HrEO + Ch coating exhibited a pronounced inhibitory effect on microbial growth, particularly by reducing total aerobic mesophilic bacteria counts. Compared to the control and Ch-only treatments, the HrEO + Ch application extended the shelf life by approximately 8% and 4%, corresponding to an estimated 3‑day improvement. Additionally, the incorporation of HrEO positively influenced the colour attributes and sensory acceptance of the fillets, enhancing their overall visual and organoleptic quality. These findings highlight the potential of HrEO-enriched chitosan coatings as an effective natural preservation strategy for maintaining the freshness and consumer appeal of fish fillets during chilled storage.