新型共混膜的制备及在烟草薄片中的应用研究

将多糖(藻酸丙二醇酯(PGA)、果胶、卡拉胶、芦荟多糖)以共干燥和直接加入两种方式对大豆分离蛋白(SPI)/脂类膜共混改性,研究多糖对膜水蒸气透过系数(WVP)及机械性能的改善作用。结果表明,共干燥法加入4种多糖,都能明显降低SPI/脂类/多糖膜的WVP;抗拉强度(TS)随着多糖的加入显著提高,而且共干燥法加入PGA还能显著提高膜的伸长率(E%);SPI/脂类膜与共干燥法制备的SPI/脂类/多糖膜阻氧性能没有显著区别。共干燥法共混改性效果优于直接加入法,且PGA对膜改性作用最为显著。多糖改性对膜微观结构的影响表明SPI、脂类、多糖形成的可食性膜微观结构决定了膜的阻隔性能和机械性能。其对烟草薄片的机械加工性能作用与前述基本一致。

Study on the Preparation of the New Blend membranes and Applied to the Tobacco Sheet

Different types of polysaccharides(propylene glycol alginate(PGA),pectin and carrageenin) were incorporated into soy protein isolate(SPI)/lipids films by co-drying preparation or direct addition to form biodegradable composite films with modified water vapor permeability(WVP) and mechanical properties.WVP of SPI/lipid/polysaccharide films decreased with the addition of polysaccharides by co-drying preparation,regardless of types of polysaccharides.Tensile strength increased with the addition of polysaccharides,and also the percentage elongation at break increased with incorporation of PGA by co-drying preparation.No remarkable differences were observed in the oxygen-barrier performance between SPI/lipid and SPI/lipid/polysaccharide films.The most significant improvement was observed through blending with PGA,and co-drying preparation showed better result than direct addition.SEM analysis showed that microstructures of the films is the basis for the differences in their barrier and mechanical properties of blend-modification among SPI,polysaccharides and lipids.