乳清分离蛋白-聚乳酸双层膜的制备及其在猪肉保鲜中的应用

蔡青文; 谢晶; 黎柳; 雷昊

doi:10.13386/j.issn1002-0306.2015.12.051

乳清分离蛋白-聚乳酸双层膜的制备及其在猪肉保鲜中的应用

Preparing bilayer films by whey protein isolate-poly lactic acid and applying on the pork preservation

摘要

摘要: 应用浇铸法制备乳清分离蛋白-聚乳酸双层可降解膜,通过膜的机械性能、水溶性、透光率、雾度等指标的测定来表征膜的包装性能,并将其应用在冷却猪肉的保鲜中。结果表明,聚乳酸的添加使单层蛋白膜的抗拉伸强度显著提高（p<0.05）,可由2.08MPa增加到12.15MPa;双层膜在未添加任何黏附剂的条件下仍能紧密粘合且显示出较高的透明度,膜的水溶性及溶胀系数也因聚乳酸的添加有所降低,膜断裂伸长率显著降低（p<0.05）。该双层膜包装冷却猪肉（4℃）,在贮藏期间（10d）,猪肉的p H、TBA值、细菌总数均低于聚乙烯膜包装的猪肉,表明双层膜能有效延长冷却猪肉的货架期。

Abstract: The bilayer films of whey protein (WPI) and poly (lactic acid) (PLA) were prepared by a simple solvent casting method in this study. The mechanical properties, water-soluble, light transmittance and haze of the films were measured. Moreover, WPI- PLA was applied to preserve the pork. The results showed that the adding of PLA could improve significantly the tensile strength of bilayer films (p<0.05) which could be increased from 2.08 MPa to 12.15 MPa. The films showed strong adhesion between layers without adding any extra component and displayed higher transparency. With the application of PLA, the water soluble, swelling index and elongation at break (EB) were reduced significantly (p<0.05) . Within 10 days storage at 4℃, p H, TBA and total bacterial count in pork packaged with this bilayer films were lower than control pork packaged with PE films significantly. The results suggested that the bilayer films could prolong the shelf life of pork effectively.