Effect Of Active PLA/PHA Packaging Film On The Flavor And Quality Of Puffer Fish During Storage

With the continuous emergence of food quality and safety issues,people pay more and more attention to the texture of food itself.Food corruption not only has an impact on human health,but also brings inconvenience to the environment,resulting in a waste of resources.Therefore,how to preserve food and extend the shelf life of food has become an important problem for human survival and development.Internal environment by changing the active packaging food packaging,packaging materials as the carrier,active component in the packaging(bacteriostatic agent,antioxidant,etc.)released into the surface of food,by surface to release the active ingredient in the food packaging materials,so as to achieve the effect of inhibiting the microbial production,extend the shelf life of food.Based on(Polylactic acid,PLA),poly(lactic acid)(PLA)polyhydroxy fatty acid ester(Polyhydroxyalkanoates,PHA)for resin base material,mass concentration of 4% Oregano Essential Oil(Oregano Essential Oil,OEO)and 4% Oregano Essential Oil(OEO)+ 4% nanometer montmorillonite(MMT,i.28)for active antibacterial antioxidants,modified by twin-screw extrusion granulation,stretch their preparation of PLA/PHA active packaging film,To explore the effect of the addition of OEO and MMT on the relative properties of active PLA/PHA films.In addition,the prepared active PLA/PHA film was applied to the frozen preservation of puffer fish fillet,and the migration amount of active substances in the active PLA/PHA film in puffer fish fillet and its influence on the quality change of puffer fish fillet were analyzed.On this basis,the effects of volatile phenolic compounds added to OEO on the main volatile components of frozen puffer fish fillet were further analyzed by gas chromatography-mass spectrometry(GC-MS)and electronic tongue technology.The main research results are as follows:(1)The biodegradable active PLA/PHA packaging film was prepared by using PLA and PHA as the resin substrate and OEO and MMT as the active substances.The mixing of OEO in PLA/PHA film effectively improved the poor brittleness performance of PLA film,improved the flexibility and ductility of active PLA/PHA film,and affected the barrier performance of PLA/PHA film to different degrees.OEO and MMT have good compatibility with PLA/PHA substrate and are better dispersed in the substrate molecules.Compared with the blank PLA/PHA film,the addition of OEO and MMT in the active PLA/PHA film does not change its microstructure.With the addition of OEO,PLA/PHA film is endowed with antibacterial properties,and it can inhibit the dominant spoilage bacteria in food to different degrees.On this basis,the effective content of OEO in active PLA/PHA film was well retained by the addition of MMT.The active PLA/PHA film prepared in this experiment can be applied to food preservation.(2)The method of GC-MS to detect the amount of active substances in active PLA/PHA transferred to puffer fish fillet is feasible;In the frozen pufferfish fillet,the migration of the principal component of OEO in the active PLA/PHA films in groups B and C was 8.36 mg/kg and 9.70 mg/kg,respectively.The addition of MMT in active PLA/PHA film effectively retained the content of OEO in the film.Characterization of the puffer fish fresh indexes and testing of all physical and chemical indexes shows that added with 4 wt % OEO,4 wt % OEO and 4 wt % MMT activity of PLA/PHA packaging film has ideal effect of the puffer fish,the puffer fish fillet OEO migration accumulation,enhance the OEO in frozen puffer fish fillet fresh antibacterial antioxidant properties,effectively inhibit the growth of microorganisms,slowly lipid oxidation,reduction,to some extent to maintain the quality of the puffer fish fillet;On the 5th day of refrigeration,the physical and chemical indexes of the fillet samples of the blank group A film package gradually reached the upper limit of acceptance,and the fish began to rot.In the experiment,the frozen puffer fish fillet packed by film in group B and group C puffer fish fillet appeared to rot on day 7 and day 8 respectively.Compared with the blank group A PLA/PHA film,the active PLA/PHA film prepared in this study effectively extended the shelf life of frozen puffer fish by 2-3 days.The antibacterial properties of the active film not only depend on the nature of the active ingredient in the film,but also on the content of the active ingredient in the film and the content of the active ingredient transferred from the film to the food.(3)The volatile components of cultured puffer fish were extracted by solid phase microextraction(SPME)and analyzed qualitatively and quantitatively by gas chromatography-mass spectrometry(GC-MS).The results of volatile component determination showed that the smell of puffer fish was significantly reduced after packaging with active PLA/PHA film,and the smell of puffer fish was the least in the active C film.Gc-ms tests were conducted on puffer fish fish packaged with three kinds of films on the 8th day of storage.It was found that the content of aldosterone in the fish of the blank group was higher than that in the fish of the experimental group,showing a significant difference.The fish in the experimental group contained heterocyclic compounds due to the addition of the active ingredient OEO,which contains a variety of heterocyclic compounds.The flavor of puffer fish under three kinds of thin film was compared with that under electronic tongue technique,and principal component analysis(PCA)was used for data analysis.PCA showed that the taste of puffer fish was partially lost during refrigeration.In the three types of PLA/PHA film packaging refrigerated,the main components in puffer fish fillets are completely differentiated,which means that the active packaging has a certain degree of influence on the flavor change of the fish.Compared with the blank group A,the active PLA/PHA film can maintain the flavor of fish in the cold-field preservation of fish,delay the fish spoilage,and thus delay the generation of unpleasant taste in puffer fish.