Improving quality of trout fillet using gelatin coating-contain peppermint essential oil loaded solid lipid nanoparticles (PEO-SLN)

The aim of the present study was to design a delivery system of peppermint essential oil (PEO loaded solid lipid nanoparticles (PEO-SLN) for evaluating the chemical and sensory properties of trout fillet during cold storage. PEO-SLN was provided through a bath sonication method and characterized by several techniques. Different formulations including glycerol monostearate (1.39 × 10 −2 –5.56 × 10 −2 mM), Tween 80 (3.18 × 10 −3 –25.44 × 10 −2 mM), and PEO (5.28 × 10 −3 mM) were applied to optimize the PEO-SLN. The optimized PEO-SLN sample showed a spherical morphology with droplet size of 139.46 ± 0.32 nm and 0.26 ± 0.01 PDI under transmission electron microscopy (TEM). Encapsulation efficiency (EE) and zeta potential were around 55.5% and − 30.64 ± 0.59 mV, respectively. Moreover, the effect of gelatin-coating containing of PEO-SLN was measured on Chemical (pH, TVB-N, TBARS, PV, and FFA) and organoleptic properties of trout fillet over a 12-day storage period. The most effective treatment against chemical deterioration was found to be gelatin-coating fortified with PEO-SLN (Gel + PEO-SLN). Furthermore, fillets which was coated with PEO-SLN had the acceptable score in all sensory attributes during storage period. The obtained results demonstrate that the incorporation of Gel + PEO-SLN into trout fillets may improve, or at least not adversely affect, their sensory properties and suggests this coating is an effective strategy to delay chemical degradation of trout fillets. In addition, the FRAP and DPPH radical scavenging of PEO-SLN exhibited a higher antioxidant activity than free PEO. This study provides useful insights into the preparation of a lipid-based delivery system enriched with essential oils for food safety applications.