Kowalczyk Dariusz, Kazimierczak Waldemar, Zięba Emil, Lis Magdalena, Wawrzkiewicz Monika
Department of Biochemistry and Food Chemistry, Faculty of Food Sciences and Biotechnology, University of Life Sciences in Lublin, Skromna 8, 20-704 Lublin, Poland.
Department of Biomedicine and Environmental Research, Faculty of Medicine, John Paul II Catholic University of Lublin, Konstantynów 1J, 20-708 Lublin, Poland.
Molecules. 2024 Dec 19;29(24):5998. doi: 10.3390/molecules29245998.
Hydrophobization could improve the moisture resistance of biopolymer-based materials, depending on the methods and materials used, providing benefits for packaging applications. The aim of this study was to compare the effect of increasing concentrations (0-2.0%) of candelilla wax (CW) and oleic acid (OA) on the structural and physicochemical properties, including water affinity, of glycerol-plasticized pea protein isolate (PPI) films. OA acidified the film-forming solution and increased its viscosity more effectively than CW. At the highest concentration, OA prevented cohesive film formation, indicating a weakening of protein self-interaction. OA caused less yellowing, matting, and a smaller reduction in UV/VIS light transmittance compared to CW. Both lipids caused a slight reduction in the films' water content. Phase separation (creaming) of CW enhanced surface hydrophobicity, resulting in a greater reduction in water vapor permeability than OA (~37-63% vs. 2-18%). The addition of lipids did not reduce film solubility or water absorption, and OA even increased these parameters. Increasing lipid content decreased the mechanical strength and stretchability of the films by 28-37% and 18-43%, respectively. The control film exhibited low heat-sealing strength (0.069 N/mm), which improved by 42% and 52% with the addition of CW and OA at optimal levels.
根据所使用的方法和材料，疏水化处理可以提高生物聚合物基材料的防潮性，这对包装应用有益。本研究的目的是比较增加小烛树蜡（CW）和油酸（OA）浓度（0-2.0%）对甘油增塑豌豆分离蛋白（PPI）薄膜的结构和物理化学性质（包括亲水性）的影响。与CW相比，OA使成膜溶液酸化，并更有效地提高了其粘度。在最高浓度下，OA阻止了粘性薄膜的形成，表明蛋白质自相互作用减弱。与CW相比，OA导致的泛黄、哑光现象更少，紫外/可见透光率的降低也更小。两种脂质都使薄膜的含水量略有降低。CW的相分离（乳油化）增强了表面疏水性，导致其水蒸气透过率的降低幅度大于OA（~37-63%对2-18%）。脂质的添加并未降低薄膜的溶解性或吸水性，OA甚至提高了这些参数。脂质含量的增加分别使薄膜的机械强度和拉伸性降低了28-37%和18-43%。对照薄膜的热封强度较低（0.069 N/mm），在最佳水平添加CW和OA后，热封强度分别提高了42%和52%。
