The Effect of Come-up Time on Fractal Dimension of Lime Juice in Thermal Processing by Conventional and Infra-red Methods

Pizhūhish va Nuāvarī dar ̒Ulūm va Sanāyi̒-i Ghaz̠āyī

卷:5

Aman Mohammad Ziaiifar¹  Sara Aghajanzadeh Suraki²  Mahdi Kashaninejad³ 

[1] Associate Professor, Department of Food Process Engineering, University of Agricultural Sciences and Natural Resources, Gorgan, Iran;

[2] Ph.D. student, Department of Food Process Engineering, University of Agricultural Sciences and Natural Resources, Gorgan, Iran;

[3] Professor, Department of Food Process Engineering, University of Agricultural Sciences and Natural Resources, Gorgan, Iran;

关键词: come up time;    fractal dimension;    infrared radiation;    lime juice;    pectin methylesterase;   

DOI  :  10.22101/jrifst.2016.09.17.526

来源: DOAJ

【 摘 要 】

Juice cloud and turbidity are considered as desirable properties in lime and other citrus juices. The turbidity is influenced by the presence of pectin in citrus juice. Pectin methylesterase (PME) causes cloud loss due to its function in desterification of the pectin. Thermal processing is commonly used to inactivate this enzyme. As the first stage of the heating process, the come up time (CUT) plays a considerable role in PME inactivation. The aim of this study was to investigate the PME inactivation, turbidity and fractal dimension (FD) changes during lime juice thermal processing using conventional (water bath) and infrared (IR) heating at 60, 70, 80 and 90 ^oC. The results showed that by rising   juice temperature, the PME inactivation and the turbidity increased during both thermal treatment methods. Therefore, the cloud particles remained suspended and less particles aggregation took place to form fractal structures, resulting in a homogeneous distribution of cloud particles and FD reduction. Due to shorter CUT, the samples heated by IR showed higher PME retention and FD in comparison with conventional processing.

【 授权许可】

Unknown