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

• Published in: Ultrasonics sonochemistry 2019-09, Vol.56, p.1-13
• Main Authors: Nowacka, Malgorzata, Wiktor, Artur, Anuszewska, Aleksandra, Dadan, Magdalena, Rybak, Katarzyna, Witrowa-Rajchert, Dorota
• Format: Article
• Language: English
• Subjects: Bioactive compounds; Colour; Cranberries; Microwave-vacuum drying; Organoleptic properties; Osmotic dehydration; Pulsed electric field; Ultrasound
• ISSN: 1350-4177; 1873-2828
• DOI: 10.1016/j.ultsonch.2019.03.023

•Innovative technologies utilisation in the production of dried cranberry snacks was studied.•The impact of different osmotic solutions on dried cranberry snacks was investigated.•Microwave-vacuum drying reduced drying time in comparison to hot-air drying.•US and PEF + US treatments reduced sugars content in dried cranberries.•Microwave-vacuum drying resulted in better retention of bioactive compounds. 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).