The application of unconventional technologies as pulsed electric field, ultrasound and microwave-vacuum drying in the production of dried cranberry snacks

Malgorzata Nowacka; Artur Wiktor; Aleksandra Anuszewska; Magdalena Dadan; Katarzyna Rybak; Dorota Witrowa-Rajchert

doi:10.1016/j.ultsonch.2019.03.023

The application of unconventional technologies as pulsed electric field, ultrasound and microwave-vacuum drying in the production of dried cranberry snacks

Ultrason Sonochem. 2019 Sep:56:1-13. doi: 10.1016/j.ultsonch.2019.03.023. Epub 2019 Mar 23.

Authors

Malgorzata Nowacka¹, Artur Wiktor², Aleksandra Anuszewska¹, Magdalena Dadan¹, Katarzyna Rybak¹, Dorota Witrowa-Rajchert¹

Affiliations

¹ Department of Food Engineering and Process Management, Faculty of Food Sciences, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-776 Warsaw, Poland.
² Department of Food Engineering and Process Management, Faculty of Food Sciences, Warsaw University of Life Sciences, Nowoursynowska 159c, 02-776 Warsaw, Poland. Electronic address: artur_wiktor@sggw.pl.

PMID: 31101243
DOI: 10.1016/j.ultsonch.2019.03.023

Abstract

A lot of effort is put to decrease the energy consumption of drying. This effect might be achieved by shift of a drying technology e.g. from a hot-air to a microwave-vacuum method. Moreover, an unconventional pre-treatment such as ultrasound or pulsed electric field may modify a cellular tissue, what influences drying kinetics of plant tissue. The aim of the study was to analyse the quality of microwave-vacuum dried, osmodehydrated (OD) cranberries processed by the means of blanching and ultrasound (US) or blanching followed by pulsed electric field and sonication (PEF + US) in comparison to traditionally treated material. Physical, chemical and sensorial properties of cranberry fruits were assessed. What is more, the impact of aforementioned unconventional treatments on the kinetics of microwave-vacuum dried cranberries was studied. Microwave-vacuum drying process was very short (25-38 min) in comparison to convective drying, which lasted several hours (13.2 h). Most of the samples subjected to US and PEF + US treatments before OD and drying were characterized by similar or a higher amount of bioactive compounds such as polyphenols, anthocyanins and flavonoids, and better colour and taste, as compared to cut osmodehydrated cranberry fruits subjected to convective drying (reference samples).

Keywords: Bioactive compounds; Colour; Cranberries; Microwave-vacuum drying; Organoleptic properties; Osmotic dehydration; Pulsed electric field; Ultrasound.