Abstract:Ethylene-vinyl alcohol copolymer (EVOH) was used as the base film material, 0.05%, 0.1% and 0.2% phytic acid was added respectively to the base film material to prepare safe fresh-keeping film by the twin-screw extrusion blow molding method.The light transmittance, water vapor transmission coefficient, haze and tensile strength were used to investigate the basic properties of the film. Bass meat was preserved by polyethylene (PE), EVOH and composite film under refrigerated (4±1) ℃ conditions, and the total viable counts (TVC), pH value, juice loss rate, total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) and sensory score were used as freshness index to evaluate the freshness. Compared with the PE film, the haze of the composite film with 0.2% phytic acid increased to 85.43%, and the light transmittance and tensile strength decreased significantly (P<0.05). During storage, the TVC, juice loss rate, TVB-N and TBA values of the samples in different packaging films increased in varying degrees, with the TVC values of the samples in the PE film and EVOH film reached unacceptable levels on the 6th and 8th day, respectively, whilst the addition of phytic acid could effectively inhibit the increase of each freshness index. Compared with the composite film, the sensory deterioration of the fish samples wrapped with PE film became significant (P<0.05). To sum up, the active film made of EVOH combined together with 0.2% phytic acid has the greatest fresh-keeping effect on the meat of bass, and can prolong the shelf life to 8 days at (4±1) ℃.
