摘要
应用质构仪、紫外可见分光光度仪、粘度仪、流变仪分别对6批具有凝胶性能的黄原胶进行了凝胶强度、丙酮酸含量、剪切性能的测定以及流变学特性的研究,并与不具有凝胶性能的黄原胶进行了比较。结果表明:具有凝胶强度的黄原胶在1722cm-1波数处酯类物质或者有机酸中C=O键吸收峰及1200~1000cm-1处各种C-O键吸收峰的强度明显增强;通过质构仪凝胶强度的测定可以区分不同黄原胶,该指标与应变扫描时损耗正切在α=0.05上具有显著相关。与不具有凝胶性能的黄原胶相比,具有较低的剪切稀化能力与牛顿流体域,具有较高的弹性模量、粘性模量、复合粘度、损耗正切及流动时的较高模量值及较小的应变值,当频率达到0.2~0.5Hz时粘性模量开始出现平台区或随频率变化缓慢的现象,在温度升高至80℃左右弹性模量、粘性模量及粘度出现明显的下降。另外,丙酮酸与剪切性能、弹性模量、粘性模量、复合粘度在α=0.05上显著相关;剪切性能与零剪切粘度在α=0.01上具有显著相关,与粘度在α=0.05上具有显著相关。
The gel strength,pyruvic acid content,shearing properties and rheological properties of 6 batches of xanthan gum with gel properties were studied by texture analyzer,UV-VIS spectrophotometer,viscometer and rheometer respectively,and compared with the xanthan gum without gel properties.The results showed that the intensity of C=O bond absorption peak at 1722cm-1 of ester or organic acid and of various C-O bond absorption peaks at 1200~1000cm-1 were significantly enhanced.The gel strength obtained by texture analyzer could be used to distinguish different xanthan gum,which was significantly correlated with the loss tangent in strain sweep atα=0.05.Compared with the xanthan gum without gel properties,it had lower shearing thinning ability and Newton fluid domain,had higher elastic modulus,viscosity modulus,complex viscosity,loss tangent and higher modulus value and smaller strain value at G′=G″.Moreover,the curve of viscous modulus in frequency sweep started to be a plateau or increase slowly when the frequency reached 0.2~0.5Hz,the right elastic modulus,viscosity modulus and viscosity decreased obviously when temperature was up to 80℃.In addition,pyruvic acid had significant correlation with shearing property,elastic modulus,viscosity modulus and complex viscosity atα=0.05,shearing property had significant correlation with zero-shearing viscosity atα=0.01,and with viscosity atα=0.05.
作者
欧凯
吴伟都
赵志红
冯玉红
李言郡
王雅琼
李卫群
OU Kai;WU Wei-du;ZHAO Zhi-hong;FENG Yu-hong;LI Yan-jun;WANG Ya-qiong;LI Wei-qun(Hangzhou Wahaha Group Company Limited,Key Laboratory of Food and Biological Engineering of Zhejiang Province,Hangzhou 310018,China)
出处
《饮料工业》
2020年第1期22-26,共5页
Beverage Industry
关键词
凝胶性能
黄原胶
凝胶强度
流变特性
丙酮酸含量
红外光谱
gel properties
xanthan gum
gel strength
rheological properties
pyruvate content
infra-red spectrum
