该研究旨在探索不同时长Plasma处理对复合蛋白基成膜溶液性能的影响。为此,采用功率为30 W的大气压Plasma对WPI-NaCas-GLY复合成膜溶液分别进行0、5、10、15、20、30、40和60 min的低温等离子体处理,研究了处理期间成膜溶液的色度、pH值、粒度、表面张力、发泡性能和乳化能力的变化以及制得薄膜的机械性能、光学性能和阻隔性能的变化。实验结果显示,随着处理时间的延长,由于活性氧及氮物质的形成及作用,成膜溶液黄度提高,pH值先增后降,蛋白质聚合使得溶液中蛋白质大分子颗粒粒径以每5 min提高一倍的速率增长,蛋白质羰基和游离巯基分别增加和减少一倍,基质表面张力降低至约35 mN/m,发泡能力降低10%,泡沫稳定性显著提升(P<0.05),由74.99 %增至94.60 %,乳化性能最高达到0.12 m2/g。所得复合蛋白膜抗拉强度增大了0.5 Mpa,透光率有所下降,氧气透过率降低至0.53 cc/(m2?day),水蒸气透过系数降低约40%。由此推论,Plasma的适时处理能够有效改善蛋白基成膜溶液疏水性、发泡能力以及乳化性能,并得到较理想的复合蛋白膜。
The present study was designed to explore the effects of Plasma treatment on properties of protein-based film-forming solutions. For this purpose, the WPI-NaCas-GLY composite film-forming solution was treated with atmospheric pressure cold Plasma of 30 W at different temperatures for 0, 5, 10, 15, 20, 30, 40 and 60 min,respectively. Changes in chromaticity, pH, particle size, surface tension, foaming properties and emulsifying capacity of the film forming solution during the treatment were observed. The results showed that the yellowness of the film forming solution rose, and the pH value waved to decline, protein polymerization increased the size of protein macromolecule particles in solution at a rate of doubling every 5 minutes with the extension of treatment time, due to the action of reactive oxygen species and nitrogen species induced by plasma. The protein carbonyl groups and free SH groups of the protein increased and decreased at the rate of doubling respectively, the surface tension of the matrix was reduced to about 35 mN/m, the foaming capacity was reduced by 10%, and the foam stability was significantly improved (P<0.05), increasing from 74.99 % to 94.60 %, and the emulsification capacity reached 0.12 m2/g. The tensile strength of the composite protein film was increased by 0.5 Mpa, light transmittance decreased, the oxygen transmission rate was reduced to 0.53 cc/(m2?day), and the water vapor transmission coefficient was reduced by about 40%. It was inferred that the timely Plasma treatment can effectively improve the hydrophobicity, foaming ability, and emulsification properties of protein-based film-forming solution, and got the ideal composite protein film.