摘要
Using biodegradable films as smart packaging to monitor the freshness of meat in real time is a promising and challenging work.Herein,the phosphorus-doped carbon dots(P-CDs)with pH sensitivity were coated on starch/polyvinyl alcohol film(SP film)by a simple scrape-coating method and applied to monitor the freshness of pork.The P-CDs@SP film exhibits a uniform surface,excellent mechanical properties,higher light blocking.When the total volatile base nitrogen(TVB-N)of pork exceeded 15 mg/100 g,the color of the film changed from brownish-yellow to purple-red,and the total color difference(ΔE)of the film obviously increased from 10.24 to 9.37 to 20.75 and 22.93 under the storage conditions of 25 and 4℃,respectively.This can be attributed to the abundant hydroxyl groups on the surface of P-CDs and SP film to promote their stable binding through hydrogen bonds,which greatly improves the hydrophilicity of the films,providing conditions for the rapid conversion of the TVB-N to ammonia and the formation of an alkaline environment.This work can simply and effectively monitor the freshness of pork through the changes of film color,will provide a new idea for the preparation of biodegradable smart packaging materials.
基金
supported by the National Natural Science Foun-dation of China(Nos.22268005 and 22178074)
Natural Science Foundation of Guangxi Province,China(Nos.2019GXNSFDA245020 and 2020GXNSFGA297001)
China Postdoctoral Science Foundation(Nos.2023MD734150).
