Kinetic Models of Evaporation and Total Phenolics Degradation during Pomegranate Juice Concentration

Abstract

Pomegranate juice was concentrated by conventional heating at different temperatures (45, 50, 55, 60, and 65°C), and the effect of temperature on evaporation rate and on thermal degradation of total phenolics was investigated. Concentration kinetics modeling was developed based on thin-layer drying models. The logarithmic model was found to give better predictions than the others. The temperature dependence of the model constants was expressed by polynomial relationships. In addition, a first-order decay model, with an Arrhenius and a polynomial dependency on temperature and water content, respectively, was used to describe the joint influence of temperature and moisture content on the thermal degradation of total phenolics in a concentration process of pomegranate juice.

Üzüm, Nar Ve Kara Havuç Sularinin Farkli Yöntemlerle Konsantrasyonunun Matemati̇ksel Modellenmesi̇

“…The experimental data from all techniques show exponential-type concentration behavior in grape, pomegranate and black carrot juice. This is in agreement with the results reported in many studies on different materials (Assawarachan and Noomhorm, 2010;Onsekizoglu, 2013;Goula et al 2014;Bozkir and Baysal, 2017). Grape, pomegranate and black carrot juice samples were concentrated to 65 °Bx by thermal methods for 114.7, 124.3 and 138.2 min.…”

“…The k-value of the Midilli model varied between -3.0816 and -0.1563, whereas the k-value of the logarithmic model varied between -0.0500 and -0.0033 in the present study (Tables 7-9). On the other hand, the k-value of the logarithmic model varied between -0.120 and -0.0003 in pomegranate juice (Goula et al 2014) and between 0.0422 and 0.0742 in pineapple juice (Assawarachan and Noomhorm, 2011).…”

“…However, the logarithmic model exhibited better fitting for the thermal concentration method at 80°C than the Midilli model. Goula et al (2014) reported that the logarithmic model was the best descriptive model for rotary vacuum evaporation of pomegranate juice, whereas Assawarachan and Noomhorm (2011) stated that the modified Page model gave better predictions for vacuum microwave concentration of pineapple juice. On the other hand, Yousefi et al (2012) used a first-order reaction model to describe the concentration of pomegranate juice during microwave and conventional concentration processes.…”

“…) to describe the drying process for different foods (Yaldýz and Ertekýn, 2001;Delgado et al 2014;Demiray and Tulek 2014;Doymaz and Karasu, 2018;Karabacak et al 2018). These models have also been used by a few researchers for the description of the concentration process for fruit juices (Assawarachan and Noomhorm, 2008;2010;Goula et al 2014;Bozkir and Baysal 2017).…”

The Effect of Cultivation Method of Strawberry (Fragaria x ananassa Duch.) cv. Honeoye on Structure and Degradation Dynamics of Pectin during Cold Storage

“…Destruction of the enzyme or the degradation of the cell structure leads to the disruption of anthocyanin biosynthesis and reduction of fruit quality. The lower yields of anthocyanin-synthesizing enzymes were particularly evident in fruit cultivated in a flat-planted plot (conventional) [ 49 ].…”