超声处理对魔芋葡甘聚糖流变与结构的影响  

Effect of ultrasonic treatment on the rheology and structure of konjac glucomannan

作　　者：彭曼曼 吴思凝 迪珂君 徐丹[1] 张甫生[1] PENG Manman;WU Sining;DI Kejun;XU Dan;ZHANG Fusheng(College of Food Science,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学食品科学学院

出　　处：《食品与发酵工业》2020年第3期152-159,共8页Food and Fermentation Industries

基　　金：重庆市自然科学基金项目(cstc2018jcyjAX0002);重庆市社会事业与民生保障科技创新项目(cstc2017shms-kjfp80020);西南大学科研基金项目(GZRY20170058)

摘　　要：为考察超声处理对魔芋葡甘聚糖(konjac glucomannan,KGM)的理化性质的影响,以溶胀完全的KGM溶胶为对象,研究不同时间、不同功率的超声处理对KGM的流变与结构的影响。结果表明,随着超声时间的增加,KGM溶胶表观黏度及储能模量(G′)和损耗模量(G″)均下降,与未经超声处理的KGM相比,超声处理时间为240min时下降最为显著,表观黏度在剪切速率为21.9s^-1时下降了46.3%,G′、G″分别在角速度为75.0rad/s时下降了44.3%和55.1%;增大超声功率,KGM溶胶表观黏度及G′和G″也均减少,处理功率为180 W时减少最为明显,180 W处理的KGM溶胶的表观黏度在剪切速率为21.9s^-1时下降了66.1%,G′、G″则分别在角速度为75.0 rad/s时下降了43.2%和41.0%。超声处理对KGM溶胶结构破坏明显,扫描电镜(scanning electron microscope,SEM)分析显示,超声使KGM的网络结构由相对连续、平整变得断裂、卷曲、松散。但红外吸收光谱(Fourier transform infrared spectrometer,FT-IR)表明超声没有对KGM分子重复结构单元和功能基团造成破坏,仅对氢键产生影响。因此,超声处理可作为改善KGM溶胶流变特性的有效手段,可拓展KGM在饮料、酸奶、化妆品等领域的应用。This paper attempts to investigate the effect of ultrasonic treatment on the physicochemical properties of konjac glucomannan(KGM).The structure and rheology of completely swelling KGM sol were studied after ultrasonic treatment with different time and power.The results indicated that KGM sol′s apparent viscosity,storage modulus(G′)and loss modulus(G″)decreased with ultrasonic time increasing.Compared with untreated KGM sol,the decrease was most significant when the ultrasonic time was 240 minutes,the apparent viscosity decreased by 46.3% at 21.9 s^-1,while G′,G″decreased by 44.3% and 55.1%at 75.0 rad/s,respectively.The higher ultrasonic power,the lower apparent viscosity,G′and G″.The most obvious decrease was obtained when ultrasonic power was 180 W,the apparent viscosity decreased by 66.1% at 21.9 s^-1,and G′,G″decreased by 43.2% and 41.0% at 75.0 rad/s,respectively.Ultrasonic treatment damaged KGM sol structure immensely.Scanning electron microscopy(SEM)confirmed that the structure of KGM sol was changed from relatively continuous,smooth to fractured,curled and loosened after ultrasonic treatment.However,Fourier infrared spectrometer spectra(FT-IR)revealed that ultrasound did not destroy the constitutional repeating unit and functional groups of KGM,only weaken the hydrogen bonding.Therefore,ultrasonic treatment is an effective way to change the rheology of KGM sol,and helps to expand the application of KGM in beverages,yogurts,cosmetics and other fields.

关 键 词：魔芋葡甘聚糖 超声 流变 结构 

分 类 号：TQ314.1[化学工程—高聚物工业]