为了增强成膜过程中的美拉德反应，以提高薄膜的功能特性，该研究以乳清分离蛋白（Whey Protein Isolate, WPI）、酪蛋白酸钠（Sodium Caseinate, NaCas）、普鲁兰多糖（Pullulan, PUL）为成膜基材。在pH 值7.0~12.0的碱性条件下，采用湿法加热（90 ℃）协同引发美拉德反应，通过成膜溶液中游离氨基酸、还原糖含量的变化和褐变程度等参数来判断其羰氨反应的程度；研究了改性薄膜的结构变化、阻隔性、热稳定性和抗氧化活性，并应用于椰子油的包装贮藏中。实验结果表明，碱性条件能够显著加速和增强热致成膜溶液的美拉德反应并提高薄膜的功能特性，且在pH值11.0条件下表现显著，薄膜性能也更为优异：氧气透过率、水蒸气透过率、抗拉强度分别达到0.045 cm3/(m2•d)、5.680×10-12 g•cm/(cm2•s•Pa)、3.61 MPa的高阻隔性和高强度；DPPH自由基清除能力和还原力分别达到95.07%和1.83，具备优良的抗氧化活性，在50 ℃加速保藏实验中，20天后椰子油的酸价和过氧化值分别为0.27 mg/g、0.12 g/100 g，显著抑制了椰子油的氧化酸败作用，延长了椰子油的货架期。研究结果为美拉德反应改性薄膜应用于延长油脂货架期提供新思路。

To enhance the Maillard reaction during the film formation process and improve their functional properties, whey protein isolate (WPI), sodium caseinate (NaCas), and pullulan polysaccharide (PUL) were used as film-forming substrates. Under alkaline conditions with a pH value of 7.0~12.0, wet heating (90 ℃) was used to synergistically trigger the Maillard reaction. The degree of carbonyl-ammonia reaction was determined by parameters such as changes in the content of free amino acids and reducing sugars in the film-forming solution and degree of browning. The structural changes, barrier properties, thermal stability and antioxidant activity of the modified films were investigated. These films were also applied to the packaging and storage of coconut oil. The results show that alkaline conditions significantly accelerate and enhance the Maillard reaction of the thermotropic film-forming solution and improve the functional properties of films. Furthermore, the performance and properties of films significantly improved at pH value 11.0. Oxygen transmittance, water vapor transmittance, and tensile strength reached 0.045 cm3/(m2•d), 5.680×10-12 g•cm/(cm2•s•Pa), and 3.61 MPa high barrier and high strength, respectively; DPPH radical scavenging ability and reducing power reached 95.07% and 1.83, respectively, achieving outstanding antioxidant activities. In the accelerated storage experiment at 50 ℃, the acid and peroxide values of coconut oil were 0.27 mg/g and 0.12 g/100 g, respectively, after 20 days. The films significantly inhibited the oxidative rancidity of coconut oil and extended its shelf life. The results provide new applications of Maillard reaction modified films to prolong the shelf life of oils and fats.

上海市教育委员会产学研项目（15cyx69）