Effect of Ultrasound Pretreatment on the Retention of Loquat Phenolics and Antioxidants during Tray and Freeze-Drying

authored by

Manolya Eser Öner, Gülay Özkan, İlayda Doğan, Tuba Esatbeyoglu, Esra Çapanoğlu Güven

Abstract

In this study, the effect of ultrasound (US) pretreatment (600W for 30 min) prior to tray drying (TD) (46±1°C at 1.10 m/s) and freeze drying (FD) (-58°C at 0.001 mbar) on the quality characteristics of loquat cubes was investigated. US pretreatment in TD demonstrated a significant decrease in drying time (19.67%) and an increase in drying rates (22.23%, p<0.05). With US pretreatment, the effective moisture diffusivity increased from 7.83x10

^-9 to 8.92x10

^-9 m

²/s in TD. The highest rehydration capacity (4.47±0.23 g/g) was found in FD samples with US. In comparison to TD and control samples, FD samples had higher phenolic contents. US pretreatment significantly reduced phenolic contents from 1551.19±142.12 to 1197.03±80.51 mg GAE/100g and from 770.12±125.93 to 374.78±71.95 mg GAE/100g for FD and TD, respectively (p<0.05). The antioxidant capacity of loquat cubes significantly decreased with TD compared to FD (p<0.05). Results indicated that FD is a viable option for drying loquat cubes with a low moisture content, high rehydration capacity, and enhanced phenolic content and antioxidant activity.

Organisation(s)

Institute of Food Science and Human Nutrition
Molecular Food Chemistry and Food Development
Institute of Food and One Health

External Organisation(s)

Alanya Alaaddin Keykubat University (ALKU)
Istanbul Technical University

Type

Article

Journal

Akademik Gıda

Volume

Pages

78-85

No. of pages

Publication date

04.09.2024

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Food Science

Electronic version(s)

https://doi.org/10.24323/akademik-gida.1543478 (Access: Open)