冻融对红豆浓浆稳定性及流变学特性的影响研究

Research on the Effect of Freeze-thaw on Stability and Rheological Properties of Red Bean Pulp

通过对红豆浓浆进行反复冻融试验,分析其冻融稳定性及流变学特性的变化,以期为其在储运及品质稳定性改善等方面提供数据参考。研究表明:红豆浓浆的结构体系在经历1次冻融循环(–18℃,储藏7天)后已经遭到了严重破坏,其稳定系数呈现显著下降趋势,析水率、澄清指数及颗粒粒度呈现显著增加趋势,而经历多次反复冻融循环后,这些指标无显著变化,但损耗角正切值(tanδ)呈现逐渐增大趋势,这说明反复冻融循环会使红豆浓浆中高聚物的数量越来越少,聚合度越来越小。冻融循环对红豆浓浆弹性模量(G′)具有相关性,而对粘性模量(G″)的影响不大。

To provide data references for the improvement of red bean pulp storage,transportation and quality stability,the changes of freeze-thaw stability and rheological properties of red bean pulp were analyzed through repeated freeze-thaw tests in this paper.The results showed that the structure system of the red bean pulp suffered serious damage after one freeze-thaw cycle(–18℃storaged 7 days),the stability coefficient significantly declined,the syneresis rate,clarify index and grain size showed significant increasing trend,these indicators had no significant changes after repeated freeze-thaw cycles,but the loss angle tangent(tanδ)showed a trend of gradual increase,indicating that the repeated freeze-thaw cycles would lead to fewer polymers and lower degree of polymerization in red bean pulp.The freeze-thaw cycle had a correlation to the elastic modulus(G′)of red bean pulp,but had little influence on the viscosity modulus(G″).