Ultrasonikasyon Destekli Vakum İmpregnasyon (Emdirme) Tekniği İle Muamele İşleminin Kivi Dilimlerinin Kuruma Kinetiği Üzerine Etkisi.

Vacuum impregnation (VI) has been frequently used as a pre-treatment in drying technology to provide energy saving. The aim of ultrasonication process is to increase mass transfer rates by opening pores in fruits and vegetables. Simultaneous use of these two pre-treatments may improve the quality and composition of a final product while providing some advantages like the development of a new product and extended shelf life. The aim of this study was to determine the effect of ultrasound assisted VI pre-treatment on drying kinetics of kiwi slices. To determine its effect, immersion at atmospheric pressure and vacuum impregnation processes were also used separately as pre-drying treatments. In this study, kiwi slices with a thickness of 6 mm were treated with impregnation solutions at 61.8% Brix value during pre-treatments. At the end of a thirty minute long pre-treatment, water from the fruit tissues was transferred into the syrup, and mass transfer ratios were 4.21% for immersion process, 5.50% for VI process and 6.63% for ultrasound assisted VI process. After pretreatments, kiwi slices were dried in a convection drier at 60°C. Drying processes were determined by mathematical modeling. For drying processes of all pre-treated kiwi slices, Henderson-Pabis and Newtonian models were best fitted mathematical models. Color analyses of dried kiwi slices revealed that the degree of reaction kinetics for color changes was fluctuating for samples pre-treated with immersion and VI processes; however, color changes in the CIE L *, a *, b * values of kiwi slices followed a zero degree reaction kinetics. Results indicated that simultaneous application of VI process with ultrasonication increased the mass transfer rates between impregnation solution and kiwi slices. [ABSTRACT FROM AUTHOR]