壳聚糖-植酸复合膜的制备及其对鲈鱼片保鲜品质的影响

以壳聚糖为成膜剂，植酸为抗氧化剂，并添加丙三醇制备一种具有保鲜性能的壳聚糖-植酸复合膜。以复合膜的拉伸强度、断裂拉伸率、水蒸气透过系数、透光率为考察指标，进行单因素试验，再以拉伸强度为响应值，运用Design Expert 软件对壳聚糖添加量、植酸添加量、丙三醇添加量进行三因素三水平响应面试验设计。以感官品质、色差、电子鼻分析为指标，探究复合膜对鲈鱼保鲜风味效果的影响。结果表明，复合膜的最佳工艺配方为：壳聚糖添加量1.5 g/100 mL，植酸添加量0.06 g/100 mL，丙三醇添加量0.225%。此条件下制成的复合膜工艺最好，拉伸强度可达29.281 MPa。由该复合膜包裹的鲈鱼片可以保持较高的感官品质，有效控制L*、a*值的降低和b*值的升高。采用电子鼻进行气味检测，发现随着储藏时间的延长，PE保鲜膜包裹的鲈鱼肉响应强度大于复合膜组。按最优配方制备的壳聚糖-植酸复合膜对鲈鱼片具有一定的保鲜效果。

Preparation of Chitosan-Phytic Acid Composite Film and the Effects on Fresh-Keeping Qualitiy of Perch Slices

A chitosan-phytic acid composite film with fresh-keeping performance was prepared using chitosan as film-forming agent and phytic acid as antioxidant with glycerol addition. The single factor experiments were carried out with the tensile strength, breaking elongation, water vapor transmittance and light transmittance of the composite films as the investigation indicators, then response surface test design with three-factor and three-level taking tensile strength as response value was conducted to optimize the chitosan, phytic acid, glycerol additions through Design Expert software. Finally the effects of composite films on fresh-keeping flavors of perches were explored taking sensory qualities, color differences and electronic nose analysis as indicators. The results showed that the optimal process formula of the composite membrane was determined as follows: chitosan addition of 1.5 g/100 mL, phytic acid addition of 0.06 g/100 mL, glycerin addition of 0.225%. The tensile strength of prepared film could reach to 29.281 MPa. The composite films wrapping could maintain high sensory qualities of perch fillets, and effectively control the decrease of L* and a* values, and the increase of b* value. The odor detection results by electronic nose demonstrated that the response intensity of perch meat wrapped in PE plastic film was greater than that in composite film group with the time extension. The chitosan-phytic acid composite film prepared under the optimal formula presented a certain fresh-keeping effects on the quality of perch fillets.