Preparation And Properties Of Oxygen Scavenging Film Based On Tea Polyphenols-?-Cyclodextrin Inclusion Complex

Food is easy to be affected by oxygen and then produce spoilage,so reduce the oxygen content in the package can effectively extend the shelf life of food.Oxygen packaging can take the initiative to remove the oxygen in the packaging,is a new type of effective food preservation technology.Currently the most extensive form of oxygen scavenger on the market is iron-based oxygen scavenger in bag,although it can effectively reduce the oxygen content in the package,but there is a risk of eating,leakage,and is not suitable for liquid beverage packaging.Therefore,adding the active oxygen scavenging material into the plastic to prepare the oxygen absorbing film so that the packaging material itself has the oxygen absorption ability,is the focus of the study of oxygen scavenging packaging.In this research,tea polyphenols was used as the oxygen scavenging agent,citric acid as the oxygen scavenging assistant,?-cyclodextrin as the wall material,the tea polyphenols-?-cyclodextrin inclusion complex was prepared through the saturated aqueous solution method.Tea polyphenols-?-cyclodextrin inclusion complex was added into LDPE resin and be extruded and granulated to prepare the oxygen scavenging film,and the effect of oxygen scavenging film on the orange juice quality was studied.The main research contents and results are as follows:(1)Influence of the ratio of tea polyphenols and ?-cyclodextrin and the adding ratio of oxygen scavenging additive on the oxygen scavenging property of the inclusion compound were researched,to determine the optimal technological preparation parameters of the inclusion complex.Results show that:when the tea polyphenols: ?-cyclodextrin: citric acid was 1:2:1,the maximum oxygen consumption could reach 95.6mL/g,the inclusion rate was 65.26%.Meanwhile,thermal stability could meet the temperature requirements for film processing.(2)Tea polyphenols-?-cyclodextrin inclusion compound was used as the filler,LDPE resin as the base material,the two materials were blended and pelletizated through the twin screw extruder,then be extruded and granulated to prepare the oxygen scavenging film.The oxygen scavenging performance,physical and mechanical properties,barrier properties and heat sealing performance etc.were seleceted as the evaluating indicators to determine the optimum oxygen scavenger content.The results showed that when the oxygen scavenger content was 5%,the maximal oxygen uptake was up to 607mL/m2 which was the best oxygen scavenging effect of the film.Meanwhile,the tensile strength,heat sealing performance,oxygen resistance and humidity resistance were also at a better level.(3)Self-made oxygen sacvenging film was used to package the fresh orange juice,the O2 content,soluble vitamin C content,total soluble solid content,pH value as the evaluation indexs,to evaluate the effect of the prepared oxygen scavenging film on the orange juice quality.The results showed that the quality indexes of the orange juice in the oxygen scavenging film group were better than that of the pure LDPE film group,which indicated that the prepared oxygen scavenging film could effectively prolong the shelf life of orange juice.