冷冻干燥对大豆分离蛋白/月桂酸膜性能的影响

Influence of Freeze-drying on Soy Protein Isolate/Lauric Acid Film Performance

通过对大豆分离蛋白/月桂酸复合膜性能水蒸气透过系数、抗拉强度、伸长率及透氧率的变化的研究,探究干燥温度对大豆分离蛋白/月桂酸复合膜的影响。运用冷冻干燥法制备大豆分离蛋白/月桂酸复合膜,在4℃、相对湿度为53%的环境下,作为试验组。以25℃、相对湿度为53%下作为对照组,评价大豆分离蛋白/月桂酸复合膜膜液及成膜后阻水、机械性能及阻氧性能的特点。研究结果表明,冷冻干燥未造成可使用膜的穿孔或破裂,而且加入月桂酸的膜的各项性能在冷冻干燥条件下性能变化较大;其中阻水性能增加,抗拉强度及延伸率变化不大,阻氧性也有所增加。因此,成膜液在冷冻干燥过程中产生了更为致密和稳定的网络结构,从而使得应用性能更为优越,冷冻干燥程序可以作为制备涂膜食品干燥的替代手段。

Through the research of the changes of water vapour permeability, tensile strength, percentage elongation, and oxygen permeability of soy protein isolate/lauric acid composite film, study the influence of drying temperature on the composite film. Prepare soy protein isolate/lauric acid composite film with freeze-drying method. With the composite film under the temperature of 4℃ and relative humidity of 53% as an experimental group, and the composite film under the temperature of 25 ℃ and relative humidity of 53% as control group to evaluate the characteristic of the composite film liquid, water blocking property, mechanical property and oxygen barrier property of the film. Freeze-drying results will not result in the perforation or the breakage of the film, and furthermore, the properties of the film with the addition of lautic acid will have a greatly changes under the condition of freeze-drying. Water block property will be increased, and the tensile strength and percentage elongation properties will almost keep the same, while the oxygen barrier property will be increased. So the film liquid has formed a network more tighten and stable during freeze-drying process, so as to improve its application properties. Freeze-drying can be used as an alternative method in food drying with coating film.