紫薯对炼乳流变及质构特性的影响

Effects of purple potato powder on rheological and textural properties of condensed milk

将紫薯粉添加至炼乳中,研制一种新型调制炼乳.向炼乳中添加质量分数为0.5%~2.5%的紫薯粉,研究炼乳体系流变、质构及微观结构的变化,并对其影响机理进行初步探讨.结果表明,紫薯炼乳表现出假塑性流体行为,流动曲线最符合Power Law模型.紫薯炼乳具有一定触变性,紫薯粉添加量低于1.5%时炼乳形变较易恢复.黏弹性测试表明,紫薯粉添加量大于1.5%时,炼乳表现出固体行为.质构测试表明,紫薯粉添加量低于2.5%时,炼乳在20℃下贮藏5个月浓稠度和黏度均较稳定.扫描电镜显示,紫薯粉添加量越高,炼乳内部网络结构表面越光滑致密.添加紫薯粉会对炼乳流动行为和食用品质产生影响,该文可为调制炼乳的工业化加工提供有效指导.

This study aimed to reveal the influences of purple potato on the rheological and textural properties of condensed milk. The rheological,texture and microstructural changes in condensed milk were studied by adding 0.5%-2.5% purple potato powder,and the mechanisms were discussed. The results showed that the condensed milk treated with purple potato had a pseudoplastic fluid behavior,and the flow curve fitted well with the Power Law model. The condensed milk with purple potato also possessed certain thixotropic property. When the content of purple potato powder was less than 1.5%( w/w ),the condensed milk was easy to recover after deformation. The viscoelastic tests showed that 1.5% and more purple potato powder could give the condensed milk a solid behavior. Moreover,the consistency and viscosity of the condensed milk with less than 2.5% purple potato powder were stable after being stored at 20℃ for 5 months. Furthermore,the higher the content of purple potato powder added,the smoother and denser the internal network structure of the condensed milk. Therefore,the flow behavior and edible quality of condensed milk were significantly affected by purple potato powder,which provides an effective guidance for industrial processing of condensed milk.