The synergistic effect of vacuum skin packaging and electrospun film on the quality of grass carp (Ctenopharyngodon idellus) surimi during refrigerated storage

In this study, the synergistic effect of vacuum skin packaging and electrospun film on various quality parameters of grass carp surimi was investigated. Firstly, the cellulose acetate phthalate (CAP) films containing oregano essential oil (OEO) were prepared by electrospinning. The morphological characterization showed that the electrospun CAP fibers were uniform and bead-free. With the addition of OEO, the diameter of the fibers decreased from 1.48 mu m to 0.99 mu m, and the antioxidant activity of the films ranged from 25.6 % to 52.8 %. The inhibition zone diameters of the films against Escherichia coli and Staphylococcus aureus were 8.2 mm and 9.8 mm, respectively. Subsequently, the electrospun films and vacuum skin packaging were applied to maintain the quality of grass carp surimi. The pressure reduction during vacuum skin packaging and the subsequent re-pressurization to atmospheric pressure due to gas permeation was utilized to accelerate the two-way mass transfer between the dissolved electrospun film and surimi. During refrigerated storage, the whiteness, water holding capacity, and textural properties of surimi treated with the combined packaging method were maintained better than those of the surimi treated with vacuum skin packaging. Moreover, compared with other treatments, the synergistic packaging method led to the lowest level of pH (6.84), total viable counts (7.56 Log CFU/g), total volatile basic nitrogen (25.39 mg N/100 g), and lipid oxidation (0.62 mg MDA/kg) after 8 days of storage. It was concluded that the combination of vacuum skin packaging and electrospun CAP film loaded with OEO could slow down the loss of commercial value and extend the shelf life of grass carp surimi.