Extraction of specific egg yolk antibodies and application in chitosan coating: effect on microbial and sensory properties of rainbow trout fillet during chilled storage

Abstract

BACKGROUND: This study investigated the effect of chitosan coating enriched with extracted egg yolk antibodies on microbial and sensory quality of rainbow trout fillet during refrigeration (4 ± 1 ∘ C). Firstly, bacterial antigen suspensions (total psychrophilic bacteria, Pseudomonas fluorescens and Shewanella putrefaciens) were injected into the breast muscles of chickens. Eggs of immunized chickens were then collected to isolate immunoglobulin from egg yolks (IgY). Fresh fish fillets were coated by chitosan solution containing different types of IgY separately, at two concentrations (60 and 90 mg mL −1 ), refrigerated for 16 days and analysed for total viable count, psychrotrophic, Pseudomonas spp., P. fluorescens and S. putrefaciens count as well as sensorial properties. RESULTS: The tested microbial values increased in all samplesduring the storage period; however, CH + IgY treated samples could significantly retard microbial growth compared to control. The shelf life of CH + IgY-P samples was extended for about 4 days, while it was extended for about 8 days in CH + IgY-S and CH + IgY-T samples, when they were compared to control (p < 0.05). Higher scores for sensory attributes were also observed in CH + IgY treated samples, especially in CH + IgY-S samples until the end of storage period. CONCLUSIONS: Accordingly, use of chitosan coating containing IgY increases the microbial and sensory quality of fish flesh at 4 ∘ C. Therefore, given the consumer interest in natural additives, chitosan coating containing IgY can be a promising candidate.

Rainbow trout fillet biopreservation by edible chitosan-based coating containing egg yolk antibody (IgY) and lycopene

“…In order to provide the desired concentrations of S. putrefaciens and P. fluorescens (10 9 CFU mL -1 ) and total spoilage bacteria, opacity adjustment, using standards McFarland methods was performed and absorption at 600 nm was measured. After centrifugation (Hettich, Germany) for 10 min at 3000 g, precipitated bacteria were disabled with saline, containing formalin 1%, within 24 h. The inactivated bacteria were washed three times with 0.9% normal saline, and used as antigen to immunize Leghorn chickens (Ehsani et al 2018).…”

“…In order to increase antibody titer, three more doses (10 9 CFU bacteria), were injected with an interval of 2 weeks. For the confirmation of the chicken's immunization, blood samples were collected and were sent to the University of Tabriz for serum separation and indirect ELISA test (Ehsani et al 2018).…”

“…It is an important source of polyunsaturated and omega-3 fatty acids. On the other hand, the fish oil is very sensitive against oxidation and corruption due to significant amounts of polyunsaturated fatty acids (PUFA) (Ehsani et al 2018).…”

“…One of the most widely used edible coatings is chitosan, a poly cationic polysaccharide, produced by deacetylation of chitin (Ehsani et al 2018). The main commercial source of chitin is shells of crustaceans.…”

Preparation, physicochemical and preservation properties of Ti/ZnO/in situ SiOx chitosan composite coatings

“…Chitosan (CS) is a natural molecular alkaline polysaccharide obtained from deacetylation chitin, with advantages including abundance and non-toxicity. [1][2][3] CS can form a semipermeable membrane on the surface of food, and effectively inhibit the invasion and growth of bacteria. Hence it has become a research hotspot in the development of natural antiseptic antibacterial agents.…”