Based On β Glucan Freshness Of Chilled Meat Fluorescent Color Indicates The Building And Application Of Materials

Chilled meat has the advantages of good sensory quality and rich nutrients,so it is loved by consumers.However,in the process of storage,transportation and sale,it will be affected by temperature,ultraviolet and other environmental factors,so it is very important to monitor the freshness of chilled meat.Smart tag is a kind of real-time monitoring of food status and changes in the composition of the packaging,consumers at any time to judge the freshness of food,assist consumers to make decisions to judge food safety,quality and other issues.β-glucan was modified with luminol and fluorescein isothiocyanate(FITC)to make it sensitive to volatile nitrogen-containing substances,and the freshness of meat was reflected by the fluorescent color change of the smart label.In this study,through blending modification and copolymerization modification,luminol and fluorescein isothiocyanate were combined withβ-glucan to prepare intelligent response tags to visually monitor the quality of chilled meat.The main contents and results are as follows:(1)In this study,β-glucan was used as the base material,and luminol was blended intoβ-glucan,and after tableting,a fluorescent colorimetric indicator sheet with ammonia gas response was prepared to monitor cold freshness in real time.The freshness of the pork.The structure and fluorescence properties of the material were characterized by Fourier transform infrared spectroscopy(FTIR)and fluorescence spectrometer.Four concentrations of ammonia water were used to simulate the ammonia gas produced during the spoilage of chilled fresh pork.Under the irradiation of 365 nm ultraviolet rays,the fluorescence colorimetric film showed a phenomenon of fluorescence quenching after dropping hydrogen peroxide,and when the pH was 8～14 The fluorescence gradually decreased to quenching after hydrogen peroxide.The colorimetric film is applied to the freshness detection of chilled pork.The volatile basic nitrogen of the pork is 23.6 mg/100g on the 8th day of storage,which has exceeded the national standard,and the blue fluorescence of the colorimetric film is quenched.The experimental results show that the fluorescent colorimetric film can be used to monitor the freshness of chilled pork.(2)Dissolveβ-glucan and FITC in N,N-dimethylformamide(DMF),use dibutyltin dilaurate(DBTDL)as a catalyst,react at 100°C for 4 hours,filter the product and dry it in vacuum for 24 hours to obtainβGlu-FITC powder.A film prepared from polyvinyl alcohol(PVA)was used as a substrate,andβGlu-FITC was covered on the PVA film by solution casting method on the substrate to prepare a fluorescent responsive film.The chemical structure and thermal properties of the synthesized products were characterized by hydrogen nuclear magnetic resonance(~1H NMR),FTIR,and differential scanning calorimetry(DSC),and the fluorescence properties ofβGlu-FITC were characterized by fluorescence spectroscopy.Under 365 nm ultraviolet irradiation,βGlu-FITC has the ability to respond to ammonia gas produced by different concentrations of ammonia water,from light green fluorescence to strong yellow-green fluorescence,and shows different fluorescence intensities in pH 8～14 solutions.When applied to cold fresh pork packaging,the pork was spoiled on the 8th day,and the TVB-N value was 22.5 mg/100g.At the same time,the fluorescent color of the fluorescent responsive film in the package changed from the initial dark green to light green,indicating that the fluorescent responsive film can effectively indicate the freshness of meat.