普鲁兰多糖-胶原蛋白复合膜的结构表征和成膜特性及其对神红葡萄的保鲜作用

Structural Characterization, Film-forming Property Analysis and Fresh-keeping Study of Prulandoligosaccharide-Collagen Composite Film for Grapes

摘要:

为提高可食性涂膜的性能,添加不同浓度的蔗糖酯,采用流延法制备普鲁兰多糖-胶原蛋白-蔗糖酯复合膜,并应用于神红葡萄的保鲜。通过扫描电镜、热重分析等多维度表征手段,研究不同蔗糖酯对薄膜的微观形貌、分子构象、流变学特性、热稳定性和阻隔性的影响,并评估其在葡萄中的保鲜效果。结果表明,蔗糖酯与普鲁兰多糖-胶原蛋白基质具有很好的相容性,且与多糖、胶原蛋白分子间存在协同作用,所成膜液为非牛顿流体,铺展性好。相较于普鲁兰多糖-胶原蛋白膜,添加蔗糖酯后,复合膜的最大崩解温度从310 ℃升至332 ℃,透光率从42%降至16.21%,氧气透过率从2.38×10_-4 ^g/(m₂^.s)增至5.62×10_-4 ^g/(m₂^.s)。在葡萄涂膜保鲜中,当蔗糖酯添加量为1%时,具有最佳的保鲜效果,腐烂率、失重率和菌落总数分别降低了43.66%、14.81%和45.11%,可滴定酸减缓了29.17%,与未涂膜组相比,葡萄货架期延长了6 d。研究为PE膜在果蔬保鲜领域的应用提供理论依据。

Abstract:

To improve the performance of the edible coating, different concentrations of sucrose esters were added, and the pullulan polysaccharide-collagen-sucrose ester composite film was prepared by the casting method and applied for the preservation of red grape. Through multi-dimensional characterization methods such as scanning electron microscopy and thermogravimetric analysis, the effects of different sucrose esters on the microscopic morphology, molecular conformation, rheological properties, thermal stability and barrier properties of the film )sucrose esters had good compatibility with the pullulan polysaccharide-collagen matrix, and there was a synergistic effect between them and the polysaccharide and collagen molecules. The formed film liquid was a non-Newtonian fluid with good spreading properties. Compared with the pullulan polysaccharide-collagen film, after adding sucrose esters, the maximum disintegration temperature of the composite film increased from 310 °C to 332 °C, the transmittance decreased from 42% to 16.21%, and the oxygen permeability increased from 2.38×10_-4 ^g/(m₂^{.s) to 5.62×10}_-4 ^g/(m₂.s). In grape coating preservation, when the sucrose ester addition amount was 1%, it had the best preservation effect. The decay rate, weight loss rate and colony count were reduced by 43.66%, 14.81% and 45.11% respectively, and the titratable acid was slowed down by 29.17%. Compared with the uncoated group, the shelf life of the grapes was extended by 6 days. The research provided a theoretical basis for the application of PE films in the preservation of fruits and vegetables.