香草醛调控蜡质玉米淀粉-壳聚糖交联薄膜的结构和性能

Structure and Property of Waxy Starch-chitosan Crosslinking Films Regulated by Vanillin

通过在蜡质玉米淀粉-壳聚糖交联薄膜中加入香草醛探讨香草醛对交联薄膜亲水性、微观形貌、结构及热性能的影响规律。未加香草醛时,随着壳聚糖添加量的增大,薄膜的水接触角由82.88°(7:3)降低至75.37°(0:10)、断面粗糙度先下降后上升、壳聚糖分子中-N-H波数逐渐降低,淀粉/壳聚糖大分子的热裂解峰值温度由336.23℃(10:0)降低至310.83℃(0:10)。加入香草醛后,随着壳聚糖添加量的增加,交联薄膜的水接触角越大、断面粗糙度越高、壳聚糖分子中-N-H波数越低,waxy淀粉/壳聚糖的热裂解温度降低。结果表明,香草醛的加入形成香草醛-壳聚糖、壳聚糖-淀粉及香草醛-淀粉三种作用力,香草醛中-CHO与壳聚糖分子中-NH3+形成-C=N键弱化淀粉与壳聚糖的交联作用,调控交联薄膜的结构和性能,该结果可以为拓宽淀粉/壳聚糖在食品包装中的应用提供数据支持和理论依据。

Waxy cornstarch-chitosan crosslinking films were prepared with vanillin. Hydrophilicity, morphology, structures and thermal properties of crosslinking films were studied with vanillin addition. When crosslinking films were prepared without vanillin, watercontact angle of samples was decreased from 82.88°(7:3) to 75.37°(0:10), the unevenness of cross-sections was decreases and then increased, the wave number of-N-H deformation vibration was reduced, and the decomposition temperature of starch/chitosan was declined from 336.23 ℃(10:0)to 310.83 ℃(0:10). Comparatively, when the films were regulated by vanillin, water contact angles and roughness were both increased with the increased mass ratio of chitosan, the wave number of-N-H deformation vibration and the decomposition temperature of starch/chitosan was declined. Results indicated that three kinds of interactions(vanillin-chitosan, waxy starch-chitosan, waxy starch-vanillin) were formed in the films, the formation of-C=N bond between-CHO of vanillin and-NH+3 of chitosan weakened the hydrogen-bond interactions between chitosan and starch, which helped to regulate the structure and property of starch-chitosan films. The investigation provided data support and theoretical basis for broadening the application of starch and chitosan in active food packaging.