Study on the Preparation of Transglutaminase Treated Whey Protein Edible Film

Edible film can be used as a barrier layer to control oxygen permeability and water permeability, hence keeping food in good condition and prolonging food shelf-life.In order to improve the barrier properties of whey protein film, the transglutaminase was used to modify whey protein.In this study, the effects of different factors on the oxygen permeability and water permeability of whey protein film were investigated.The results showed that according to the oxygen permeability of whey protein film, the order of the influencing factors was enzyme reaction time, protein mass concentration, solution pH and enzyme content.According to the water permeability of whey protein film, the order of the influencing factors was enzyme reaction time, solution pH, enzyme content and protein mass concentration.The optimum conditions obtained through comprehensive balance method were as follows:the enzyme reaction time was 70 min, the enzyme content was 60 U/g, the whey protein mass concentration was 105 g/L and the film formation solution pH was 7.5.Under those conditions, the oxygen permeability and the water permeability of whey protein film was(4.99±0.12) g/(m²·d) and 1.21±0.05 g·mm/(m²·h·kPa), respectively.Compared with untreated whey protein film, the oxygen permeability and the water permeability of transglutaminase treated whey protein film was reduced 59.88% and 15.38%, respectively.