| Food spoilage caused by pathogenic microorganisms has become a major global concern as it significantly reduces the shelf life of food and increases the risk of foodborne illness.Among them,active packaging,aimed at controlling the development of putrefaction and pathogenic microorganisms,has become a promising technology that can extend the shelf life,maintain food safety,reduce waste and minimize the risk of foodborne diseases.In this paper,based on the natural antibacterial agent oregano essential oil(OEO)and nano silica(MNS)to build a slow release system,study the bacteriostatic mechanism,and prepare the active composite film,applied in the preservation of Agaricus bisporus.The main research results are as follows:(1)We developed a new safe and environmentally friendly antifungal system-oregano essential oil/ mesoporous nano-silica(OEO-MNS).The antifungal mechanism of OEO-MNS was investigated against the mold(Curvularia lunata MF380802.1,C.lunata)found in postharvest rotting Agarifera bisporus.Transmission electron microscopy,infrared spectroscopy and thermal stability of MNS and OEO-MNS confirm the successful embedding of OEO into MNS.The results showed that OEO-MNS had minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MFC)at 0.2 mg/m L and 0.4 mg/m L,respectively.In addition,during the interaction with OEO-MNS,the integrity of the cell membrane of Curiospora crescent is destroyed,resulting in the exudation of nucleic acids,proteins and other substances in vitro.(2)As a natural bioinhibitor,Oregano essential oil(OEO)has strong antioxidant and antifungal potential,but its volatility and instability are limited.In this study,OEO was loaded onto mesoporous nano-silicon(MNS)to prolong the efficacy of bioinhibitors,and then oxidized esterified tapioca starch(OETS)was used as film forming substrate to prepare films with potential antioxidant and antifungal properties by casting method.Then,the microstructure,physical properties,barrier properties,antioxidant properties and antifungal properties of OEOMNS active films were evaluated and compared with OETS active films.The results showed that the presence of OEO-MNS made the films have antioxidant,antifungal and UV blocking properties,and improved tensile strength(TS)and water resistance.Among them,the film containing 0.9 % OEO-MNS has the best performance and uniform distribution of nanoparticles.Meanwhile,the TS of active films reached 6.97 MPa,which was 236 % higher than that of pure OETS films.In addition,the antioxidant capacity and antifungal effect of active membranes were positively correlated with the increase of OEO-MNS supplemental level,and the membranes supplemented with 1.5 % OEO-MNS had the highest antioxidant capacity and good antifungal activity.The prepared multifunctional nano-composite film containing essential oil has a broad application prospect in the field of active packaging.(3)The freshness of Agaricus bisporus was tested by the composite film packaging technology combining OEO and slow-release nanoparticles,and the changes of physicochemical properties and enzyme activities of Agaricus bisporus stored at 4 ± 1 °C for 12 days were analyzed.The results showed that the films containing OEO and MNS delayed the aging of Agaricus bisporus to varying degrees.Among all treatment groups,OEO-MNS-TS coated mushrooms maintained better hardness(3.11 MPa)on day 12,and increased the soluble protein content by 45 %,total sugars by 363 %,total phenols by 138 % and flavonoids by 183 % at the end of storage compared with the blank control group,which reduces the rate of nutrient decline,maintains the color,shape,fullness and texture of Agaricus bisporus,and improves its commercial value.In addition,the OEO-MNS-TS film packaging mitigates the respiration rate and microbial-induced spoilage of Agaricus bisporus,reduces oxidative damage,thereby delaying aging and extending the shelf life of mushrooms,and effectively avoids packaging contamination.Therefore,the packaging treatment can be effectively used for the compound preservation of Agaricus bisporus after harvest storage and distribution to prevent the degradation of mushroom quality. |
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