Preparation Of Collagen Casing Films Using Natural Casings

Natural casing is a kind of film that has certain strength and barrier properties, which is made from animal gut through salted or dried method. It has a long history to use natural casings as sausages’packing material. However, as a kind of natural resource, natural casing has a series of problems when be commercial used, especially the high defective percentage and low productivity. So recycling this part of defective natural casing to produce edible casing film has important practical significance and commercial value.This article studied the possibility and mechanism to use the homemade single screw extruder to produce tubular films through defective natural casing. Through the research we found that plasticizer, cross-linker, pH and drying temperature have great influence in the properties of the film, and we analyzed the film formation mechanism and affecting factors through the micro perspective using FT-IR, XRD, SEM and TGA. Through the research, we successfully produced the tubular films using homemade single screw extruder. From these affecting factors we found that plasticizer and cross-linker have the biggest influence in the mechanical properties and swelling property of the film, and pH and drying temperature also have influences in the properties of the film. We think the optimal preparation conditions are3wt%(GLY/casings),0.04wt%(GTA/casings), pH9, drying temperature50℃, and the properties of the films can reach at40MPa (TS),50%(E),0.140ng.m/m2.s.Pa (WVP),120%(swelling%).