Comparing the effects of glazing and chitosan-based coating applied on frozen salmon on its organoleptic and physicochemical characteristics over six-months storage

Abstract

The perishable nature of fish, with an increase in fish consumption in recent years, led to the improvement of fish preservation techniques. Chitosan coatings adds to the traditional water glazing. The effect of a chitosan solution of 1.5% on the sensory properties of Atlantic salmon (Salmo salar) was studied over six months of storage. The sensory properties of the salmon were assessed through the use of a texturometer and a trained panel of judges. Microbiological parameters were studied in the form of Total Volatile Base Nitrogen (TVB-N) and Total Viable Count (TVC) tests. Microbiological analysis showed that chitosan had an anti-microbiological effect on the salmon samples, reducing the number of microorganisms present, while TVB-N values were maintained stable during experiment. Textural Profile Analysis (TPA) was performed and the results showed no significant differences between different coatings regarding texture. Sensory analysis by a trained panel showed that chitosan was a better choice in frozen samples, while in thawed and cooked samples no significant differences existed between chitosan-coated and glazed samples. Flavor diffusion from the chitosan coating was assessed, and analysis of the results showed no correlation between coating type and sample flavor, indicating that no flavor diffusion had occurred.

Low-Field NMR and MRI to Analyze the Effect of Edible Coating Incorporated with MAP on Qualities of Half-Smooth Tongue Sole (Cynoglossus Semilaevis Günther) Fillets during Refrigerated Storage

“…Briefly, no significant differences were detected in T 21 time among different treated samples in the current experiment, indicating transverse time T 21 was not affected by treated methods as well as storage time. Wang previously pointed out that T 22 diminished while T 23 increase with time in muscle [16]. But the conclusions disagreed with the results in the present study.…”

“…The multiexponential fitting of transverse relaxation T 2 distribution was carried out by Origin software and the protons associated with three types of water were identified. These results were consistent with some researches [14,16]. As shown in Table 1, the shortest relaxation time T 21 in the range of 1.32-6.14 ms was detected, representing the bound water entrapped within tertiary and quaternary protein structures.…”

“…Previous researches have also confirmed that LF-NMR measurements were associated with quality parameters, such as WHC, drip loss, color, and so on [16,27,28]. In the current study, the relationship between LF-NMR relaxation parameters and quality indexes was investigated during refrigerated storage (Table 2).…”

“…No significant difference was detected in images brightness of samples treated with edible coating combined with MAP at the beginning stage, while obvious changes occurred in the control group, especially CK1. From the 15th day, the color of CK1 was bluer and darker than that of other samples, as demonstrated by Wang et al [16], which indicated the degradation of the myofibrils and destruction of the microstructure in CK1. Those results were consistent with the changes of transverse relaxation of LF-NMR.…”

“…TVB-N value is usually considered as an important index to assess the quality and shelf life of aquatic products [16]. As shown in Figure 1d, the initial at day 0 was 7.14 mg/100g and there was an increase in all the samples during storage.…”