冻融处理对淀粉膜结构、热稳定性、机械性能及物理性质的影响  

Effect of Freeze-Thaw Treatment on Structural,Thermal,Mechanical and Physical Properties of Starch-Based Films

作　　者：高珊 于力 邓云[1] 王丹凤[1] 钟宇[1] GAO Shan;YU Li;DENG Yun;WANG Danfeng;ZHONG Yu(SJTU-OSU Innovation Center for Environmental Sustainability and Food Control,Key Laboratory of Urban Agriculture,Ministry of Agriculture and Rural Affairs,School of Agriculture and Biology,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学农业与生物学院,上海交通大学-OSU环境可持续性与食品控制创新中心,农业农村部都市农业重点实验室,上海200240

出　　处：《食品科学》2021年第21期72-79,共8页Food Science

基　　金：国家自然科学基金面上项目(32072270);“十三五”国家重点研发计划项目(2018YFD0401305);上海市科学技术委员会项目(19DZ2284200)。

摘　　要：本实验分别以天然马铃薯淀粉(potatostarch,PS)、改性马铃薯淀粉(包括羟丙基二淀粉磷酸酯(hydroxypropyl distarch phosphate,HDP)、醋酸淀粉(acetate starch,AS)和氧化淀粉(oxidized starch,OS))为基材,通过流延法制备可食用淀粉膜,考察冻融处理对膜物理性质、机械性能、阻隔性能、微观结构和热稳定性的影响。X射线衍射结果表明,马铃薯来源的淀粉颗粒具有典型的B型晶体结构,在成膜过程中淀粉结晶度降低,冻融处理后淀粉膜晶体峰强度明显减弱。扫描电子显微镜观察结果显示,冻融处理破坏了淀粉膜的微观结构,其中PS膜上出现明显裂纹,AS膜上出现蜂窝和层状结构,而HDP和OS淀粉膜具有更完整的形态。热重分析结果表明,随着温度的升高,淀粉膜的热重曲线出现4个质量损失阶段,分别对应水分散失、甘油挥发、淀粉解聚及淀粉分解,而冻融处理对膜热稳定性影响较小。常温条件下,PS膜具有最佳的机械性能,其拉伸强度为2.29 MPa,断裂伸长率为68.82%。在3个冻融循环后,淀粉膜的拉伸强度至少增加了2倍,断裂伸长率普遍降低,而溶解度和水蒸气透过率仅有轻微变化。综合考虑不同淀粉膜微观结构、机械性能、水蒸气透过率及水溶性,HDP膜表现出更好的冻融稳定性,可应用于冷冻低水分食品的保藏。A series of edible films were obtained using native potato starch(PS)or modified potato starches,including hydroxypropyl distarch phosphate(HDP),acetate starch(AS)and oxidized starch(OS)by the casting method.The effects of freeze-thaw(F-T)treatment on the physical,mechanical and barrier properties,microstructure and thermal stability of the films were studied.X-ray diffraction(XRD)indicated that potato starch granules displayed a typical B-type crystalline structure,the crystallinity was damaged during the film-forming process,and the peak intensity was decreased obviously after F-T treatment.F-T treatment damaged the microstructure of starch-based films as observed by scanning electron microscopy(SEM),and there appeared obvious cracks on PS film,and honeycomb-like and lamellar structures on AS film,while OS and HDP films maintained a more complete morphology.In the thermogravimetric curves of starch-based films,four stages of mass loss appeared as temperature increased,corresponding to water loss,volatilization of glycerol,and depolymerization and decomposition of starch,respectively.Nevertheless,F-T treatment had little effects on the thermostability.At room temperature,PS film had the best mechanical property with tensile strength(TS)of 2.29 MPa and elongation at break(EB)of 68.82%.After three F-T cycles,film TS increased at least twice and EB generally declined,while solubility and WVP changed only a little.HDP film displayed much better F-T stability considering the microstructure,mechanical property,water vapor permeability and water solubility collectively,indicating its potential applications in frozen low-moisture foods.

关 键 词：可食性淀粉膜 冻融稳定性 改性淀粉 物理性质 结构表征 

分 类 号：TS206.4[轻工技术与工程—食品科学]