高分子量普鲁兰多糖保鲜复合膜的制备及性能研究

Preparation and characterization of high molecular pullulan blended films

目的:利用普鲁兰多糖优良特性,复配抗菌、成膜等添加剂,制备普鲁兰多糖基复合膜,并研究其对富士苹果的保鲜作用。方法:以2.5%普鲁兰多糖为成膜基质,复配甘油、CaCl_2、壳聚糖、蔗糖酯、大豆分离蛋白海藻酸钠、羧甲基纤维素钠等功能成膜添加剂制备复合膜,对膜的物理特性进行研究。利用筛选后的复合膜保鲜富士苹果,分析其保鲜过程中失重率、POD、PPO的变化,研究保鲜复合膜的保鲜功能。通过膜抗菌作用,研究其延长鲜切富士苹果货架期的能力。结果:通过复配发现,加入其他物质均会导致膜抗拉强度的下降;而加入CaCl_2和甘油时复合膜的断裂延伸率上升,是良好的成膜添加剂,通过优化最终确定保鲜复合膜配方。同时对比其他配方,发现利用保鲜复合膜对富士苹果保鲜时失重率、硬度、可溶性固形物和Vc方面均有所提高。同时改良后的保鲜复合膜液对鲜切富士苹果的保鲜效果也非常明显,4 d后褐变程度、PPO、POD均优于对照组。结论:2.5%普鲁兰多糖复配0.5%甘油和1%CaCl_2为良好的保鲜复合膜配方,对富士苹果常温保鲜具有明显效果。同时改良后的复合膜液可作为鲜切富士苹果的保鲜剂,对延长其货架期有显著作用。

The use of pullulan properties, compound antibacterial, film-forming additives, preparation of pullulan composite film, and study its effect on the preservation of Fuji apple. In 2.5% pullulan as film- forming material, compound glycerin, CaCI2, chitosan, sucrose ester, sodium alginate, soy protein isolate sodium carboxymethyl cellulose functional film-forming additives for preparing composite membrane, and studied physical characteristics of the film. The preservation of Fuji apple was studied by using the screened composite membrane, and the weight loss rates, the changes of POD and PPO in the process of preservation were analyzed, and the fresh-keeping function of the fresh-keeping composite film was studied. The ability of prolonging the shelf life of fresh cut Fuji apple was studied by antibacterial action of membrane. It was found that the mixture of other substances may result in the decrease of tensile strength and fracture, adding CaCl2 and glycerol composite membrane elongation is increased, good film-forming additives, by optimizing the final compound film formula. At the same time, compared with other formulations, it was found that the use of fresh-keeping composite membrane improved the weight loss, firmness, soluble solids and Vc of Fuji apple. At the same time, the fresh-keeping effect of the modified fresh-keeping composite membrane on fresh cut Fuji Apple was also very obvious. The degree of browning, PPO and POD were better than those of the control group after 4 days. 2.5% pullulan mixed 0.5% glycerol and 1% CaCl2 compound film could be good formula, has obvious effect on the Fuji apple preservation at room temperature. At the same time, the improved composite film solution can be used as a preservative for fresh cut Fuji apple, and has a significant effect on prolonging shelf life.