青稞β-葡聚糖凝胶热特性、华体会(中国)粘弹性及微观结构研究
Study on the thermal property,dynamic viscoelasticity and microstructure of Hulless barley β- glucan gel
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摘要: 本文采用差示扫描量热仪(DSC)、华体会(中国)粘弹谱仪(DMA)及原子力显微镜(AFM)研究了青稞β-葡聚糖(BG)凝胶的热特性、华体会(中国)粘弹性及微观结构变化,旨在为BG凝胶在食品中的应用提供依据。DSC结果表明,当样品的储存温度相同时,BG凝胶随着浓度的升高起始温度(T0)、峰值温度(Tp)、最终温度(Tc)及热焓值(ΔH)增加;而当样品浓度相同时,凝胶热稳定性随温度增加而降低;DMA实验表明,BG凝胶的浓度越大、形成温度越低,弹性响应的系数(G’)值越大,表明BG分子间的交联增加,凝胶的弹性增强;AFM结果显示青稞BG分子会发生自然聚集,且随着浓度增加和存放时间的延长,聚集程度就越高,当其浓度为100μg/m L时样品中就会出现网络状聚集结构。Abstract: The thermal property and dynamic viscoelasticity of Hulless barley β- glucan gel( BG) as well as microstructure were investigated respectively in order to provide a theory foundation on food industry. The differential scanning calorimeter( DSC) analysis showed that the onset temperature( To),peak temperature( Tp),end temperature( Tc) and enthalpy of gelatinization( ΔH) increased with the increase of the concentration,when the gels were prepared in the same temperature; while the gels had the same concentration,the thermostability of gels decreased with the increase of the preparation temperature. The dynamic viscoelastometer( DMA) analysis demonstrated that the value of G' increased with the increase of solution concentration and the preparation temperature,suggesting that the cross- linked structures among the gels was increased. The atomic force microscope( AFM) indicated that the BG molecules could naturally gather.In addition,the aggregation level of BG molecules became higher with the rise of gels concentration and the extension of the storing time of gels.Especially,when solution concentration was 100 μg / m L,the network- like structures would be formed among BG molecules.