Premium
Ultrasound assisted low‐temperature drying of kiwifruit: Effects on drying kinetics, bioactive compounds and antioxidant activity
Author(s) -
Vallespir Francisca,
Rodríguez Óscar,
Cárcel Juan A,
Rosselló Carmen,
Simal Susana
Publication year - 2019
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.9503
Subject(s) - antioxidant , chemistry , ultrasound , food science , ascorbic acid , polyphenol , kinetics , diffusion , shelf life , vitamin c , chromatography , biochemistry , physics , quantum mechanics , acoustics , thermodynamics
Background Low‐temperature drying is considered to be a promising technique for food processing. It preserves thermolabile compounds and might be intensified by acoustic assistance. The effect of acoustic assistance (20.5 kW m −3 ) during low‐temperature drying of kiwifruit (at 5, 10 and 15 °C, and 1 m s −1 ) on drying kinetics, bioactive compounds (such as ascorbic acid, vitamin E, and total polyphenols), and antioxidant activity was studied. Results Drying time was shortened by 55–65% when using power ultrasound. A diffusion model was used to evaluate the drying kinetics. The effective diffusion coefficient increased by 154 ± 30% and the external mass transfer coefficient increased by 158 ± 66% when ultrasound was applied during drying, compared with drying without ultrasound application. With regard to bioactive compounds and antioxidant activity, although samples dried at 15 °C presented significantly higher ( P < 0.05) losses (39–54% and 57–69%, respectively) than samples dried at 5 °C (14–43% and 23–50%, respectively) when ultrasound was not applied, the application of ultrasound during drying at 15 °C significantly reduced ( P < 0.05) those losses in all quality parameters (15–47% and 47–58%, respectively). Conclusion Overall, low‐temperature drying of kiwifruit was enhanced by acoustic assistance preserving bioactive compounds and antioxidant activity, especially at 15 °C. © 2018 Society of Chemical Industry