鱼皮明胶蛋白膜的制备及其性质改良

利用罗非鱼鱼皮提取明胶制备蛋白膜,考察了浸提条件和戊二醛的添加对明胶蛋白膜性质的影响.结果表明,利用罗非鱼鱼皮可以制备成无色透明的明胶蛋白膜.在80℃水浴条件下,伴随着明胶浸提时间的延长,膜的抗拉伸强度（TS）出现先上升后下降的趋势,在浸提时间为1.0 h时达到最大值.而膜的断裂延伸率（EAB）和水蒸气透过率（WVP）则随着浸提时间的增加而下降.然而,浸提时间对膜的透光率没有显著影响.另一方面,当利用质量分数为1%～4%（相对明胶蛋白）的戊二醛对蛋白膜进行改性时,膜的TS、EAB、WVP和溶解性均明显下降,而蛋白膜的色泽变黄,紫外线阻隔能力增强.利用SDS-PAGE分析发现,戊二醛的添加会使明胶分子发生交联反应,且反应更易在高分子成分之间发生.

Preparation and Improvement of Gelatin Films Based on Tilapia Skin

The effect of extraction conditions and glutaraldehyde（GLU）incorporation on the physical and chemical properties of the gelatin films prepared from tilapia skin was investigated.As a result,colorless and transparent edible film could be successfully prepared using tilapia skin gelatin.The tensile strength（TS）of films as prepared from gelatin extracted at 80 ℃ increased and reached a peak after extraction for 1.0 h,while a gradual decrease of TS was observed when the extraction time was increased.The elongation at break（EAB） and water vapor permeability（WVP） of films were enhanced together with the increase of gelatin extraction time at 80 ℃.However,the light transmition of films was not affected by extraction time.On the other hand,when GLU was incorporated in the film-forming solutions at 1%~4%（m/m） of protein,the TS,EAB,WVP and solubility of films all decreased,while the yellowness and barrier properties against UV lights increased.SDS-PAGE analysis indicated that the protein cross-linking reaction mainly involved in high molecular weight polymers was induced by GLU.