Izvorni znanstveni članak
https://doi.org/10.17113/ftb.55.02.17.4942
Hybrid Drying of Carrot Preliminary Processed with Ultrasonically Assisted Osmotic Dehydration
Dominik Mierzwa
; Poznań University of Technology, Department of Process Engineering, Institute of Technology and Chemical Engineering, ul. Berdychowo 4, PL-60-965 Poznań, Poland
Stefan Jan Kowalski
; Poznań University of Technology, Department of Process Engineering, Institute of Technology and Chemical Engineering, ul. Berdychowo 4, PL-60-965 Poznań, Poland
Joanna Kroehnke
; Poznań University of Technology, Department of Process Engineering, Institute of Technology and Chemical Engineering, ul. Berdychowo 4, PL-60-965 Poznań, Poland
Sažetak
In this paper the kinetics of osmotic dehydration of carrot and the influence of this pretreatment on the post-drying processes and the quality of obtained products are analysed. Osmotic dehydration was carried out in the aqueous fructose solution in two different ways: with and without ultrasound assistance. In the first part of the research, the kinetics of osmotic dehydration was analysed on the basis of osmotic dewatering rate, water loss and solid gain. Next, the effective time of dehydration was determined and in the second part of research samples were initially dehydrated for 30 min and dried. Five different procedures of drying were established on the grounds of convective method enhanced with microwave and infrared radiation. The influence of osmotic dehydration on the drying kinetics and final product quality was analysed. It was found that it did not influence the drying kinetics significantly but positively affected the final product quality. Negligible influence on the drying kinetics was attributed to solid uptake, which may block the pores, hindering heat and mass transfer. It was also concluded that the application of microwave
and/or infrared radiation during convective drying significantly
influenced the kinetics of the final stage of drying. A proper combination of aforementioned techniques of hybrid drying allows reducing the drying time. Differences between the particular dehydration methods and drying schedules were discussed.
Ključne riječi
osmotic dehydration; ultrasound; microwaves; hybrid drying; dry product colour
Hrčak ID:
183066
URI
Datum izdavanja:
14.6.2017.
Posjeta: 1.364 *