Preservative Effect of Novel Combined Treatment with Electrolyzed Active Water and Lysozyme Enzyme to Increase the Storage Life of Vacuum-Packaged Carp

Abstract

In the present study, common carp (Cyprinus carpio), a highly valuable worldwide commercial fish species, was used as a model. One sample group of fresh, skin-on carp fillets was placed in a bath of acidic electrolyzed oxidizing (AEO) water containing a solution of 100 mg/kg chloride ion concentration for 5 minutes. Another sample group was treated with acidic electrolyzed water and 0.5% lysozyme enzyme solution. Another set of samples were washed after the AEO water treatment. Within the study, a storage test was performed to examine the effect of the new combined treatment on the samples' shelf-life and quality while kept at 2°C. During the storage period, chemical (chlorate) and microbiological (TVC, mesophilic anaerobic plate count, and Enterobacteriaceae count) tests and sensory evaluation were conducted. e combination of AEO water and lysozyme enzyme showed additional bactericidal efficacy on the surface of the carp fillets, which has never been reported before. Both the AEO water and the combined treatment effectively increased the shelf life of the samples, causing 2.4-3.1 log CFU/g difference compared to the control by the end of the 7-day storage. e measured residual chlorate content exceeded the legal threshold, but washing the samples resulted in values below the theoretical threshold limit. e applied preservation methods did not have an adverse effect on the organoleptic properties of the samples.

Applications of Lysozyme, an Innate Immune Defense Factor, as an Alternative Antibiotic

“…Since lysozyme exhibited weak inhibitory effects against Gram-negative bacteria, when used alone, the practical application of free lysozyme as a food preservative was quite limited and many methods used to enhance the susceptibility of Gram-negative bacteria were attempted, namely the combined use with cinnamaldehyde [ 177 ]; acidic electrolyzed oxidizing water [ 178 ]; heat treatment and hydrogen peroxide associated with a packaging in a controlled atmosphere [ 179 ]; high hydrostatic pressure [ 180 ]; disodium ethylenediaminetetraacetate salt and ethylenediaminetetraacetic acid [ 181 , 182 ]; chitooligosaccharides [ 183 ]; chitosan-organic rectorite composites and negatively charged sodium alginate film-coated cellulose acetate mats [ 184 ]; EDTA in starch-based active food packaging film [ 185 ]; enterocin AS-48 [ 186 ]; and pomegranate peel extract [ 187 ]. The relevant data on the synergic uses of these substances with lysozyme are summarized in Table 1 .…”

Perceived Risk of Fish Consumption in a Low Fish Consumption Country

“…Seeking to increase fish consumption, the Hungarian government reduced the VAT for fish by 22% in 1 January 2018. In Hungary, carp is one of the most popular species of fish [ 22 , 23 ]. Changes in the price of a slice of carp, in monthly intervals in 2017 and 2018 (the year before and after the reduced VAT) are illustrated in Figure 1 .…”

Inactivation of two SARS-CoV-2 virus surrogates by electron beam irradiation on large yellow croaker slices and their packaging surfaces

“…The sensory evaluation of large yellow croaker samples was slightly modified as described previously ( Palotás, Palotás, Jónás, Lehel, & Friedrich, 2020 ). The evaluation team was composed of 10 professional evaluators (5 male and 5 female).…”