| C.jejuni is one of the common food-borne pathogens that cause bacterial food poisoning by infecting livestock products.In this study,TEO and β-CD were used as the core material and wall material,respectively.The TEO/β-CD inclusion complex was prepared via the saturated aqueous solution method.TEO/β-CD ?-PL nanoparticles were obtained by ion-crosslinking method.TEO/β-CD ?-PL nanoparticles were obtained by ion-crosslinking method.Subsequently,TEO/β-CD ?-PL gelatin nanofibers was prepared by high-voltage electrospinning technology.The antibacterial effect of the nanofibers on meat products was evaluated as well.The main contents and results are as follows:(1)Antibacterial activity of TEO and its antibacterial mechanismBased on GC-MS analysis,the TEO contains more than 11 volatile components.The main component was thymol,with a content of 37.63%,followed by cymene and carvacrol with contents of 24.12% and 11.45%,respectively.The antibacterial experiment showed that TEO has broad spectrum and highly effective antibacterial properties.Both MIC and MBC of the 12 experimental bacteria are in the range of 0.5-1.0 mg/mL,and both MIC and MBC of C.jejuni are 0.5 mg/mL.The sterilization rate of TEO against C.jejuni could reach 99.999%,the DPPH·radical scavenging rate reached 59.13%,and the antioxidant index reached 26.15%.After treatment with TEO,the permeability of the cell membrane changed,the content of soluble protein decreased significantly,the content of intracellular DNA and ATP decreased by 78.30% and 67.97%,and the conductivity was increased by 40.82%.(2)Preparation and characterization of TEO/β-CD ?-PL nanoparticlesFirstly,this effect of some parameters on TEO/β-CD inclusion rate and TEO embedding rate were investigated,such as mass ratio of TEO to β-CD,reaction temperature(°C),reaction time(h)and ultrasonic power(W).The optimum preparation conditions were as follows: the mass ratio of TEO to β-CD was 1:8,reaction temperature was 50 °C,reaction time was 2.5 h,ultrasonic power was 120 W.Under the optimal conditions,the highest inclusion rate and TEO embedding rate were up to 79.81% and 19.68%,respectively.Secondly,TEO/β-CD ?-PL nanoparticles were synthesized by ion-crosslinking technique,and FTIR indicated that the TEO was embedded into β-CD successfully.Meanwhile,TEO/β-CD ?-PL nanoparticles exhibited an effective antibacterial effect on C.jejuni.After 48 h treatment,the sterilization rate was 99.99%.(3)Preparation and characterization of TEO/β-CD ?-PL gelatin nanofibersIn this study,gelatin with good biodegradability was selected as the substrate material,and TEO/β-CD ?-PL gelatin nanofibers was prepared by high-voltage electrospinning technology.The nanofibers are uniform and delicate,which is suitable for food packaging materials.SEM and AFM show that the nanofibers shows a uniform and disordered network structure with good continuity,no broken filaments,and uniform diameter distribution.The average diameter is 206.2 nm.The nanofibers had an effective antibacterial effect on C.jejuni.After 48 h,the sterilization rate was 99.99%.(4)The preservation effect of TEO/β-CD ?-PL gelatin nanofibers on meat productsFresh chicken and pork were used to study the preservation effect of TEO/β-CD ?-PL gelatin nanofibers during storage.The population of C.jejuni,total number of colonies and TBA values showed that the nanofibers had good antibacterial and antioxidant effects on meat products.The changes of TVB-N and p H value verified that the nanofibers can effectively delay the spoilage of meat products.Chromaticity evaluation,texture analysis and sensory evaluation showed that the nanofibers not only have no impact on meat products,but also can effectively maintain their quality.It has good application perspective in the storage and preservation of meat products. |
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