fulltext.study @t Gmail

Effect of temperature on hot-air drying rate and on retention of antioxidant capacity in apple leathers

Paper ID Volume ID Publish Year Pages File Format Full-Text
19094 43045 2013 9 PDF Available
Title
Effect of temperature on hot-air drying rate and on retention of antioxidant capacity in apple leathers
Abstract

Fruit leathers are pectic gels, eaten as snack or dessert, obtained by dehydrating fruit purees. In this work, apple leathers were prepared by a hot-air drying process which allows the formation of a gel, following the “saccharide–acid–high methoxyl pectin” gelation mechanism. Leathers were produced at 50, 60 and 70 °C, from two formulations: control and added with potassium metabisulphite (KM) as antioxidant. The drying process was studied applying a diffusive model, while antioxidant capacity (AC) losses were represented by a first-order model. Activation energy for drying (20.6 kJ/mol) was lower than those estimated for AC losses in control (31.5 kJ/mol) and KM-added (37.9 kJ/mol) leathers. Therefore, the drying time reduction achieved by increasing air temperature is not sufficient to decrease AC losses in the range covered. AC retention decreased in both formulations at increasing air temperature. KM-added samples showed higher AC retention than the controls, except for those dried at 70 °C. Kinetic constants were lower for KM-added samples, suggesting a protective effect of the additive, especially at moderate air temperatures. In the most favorable situation, AC retention was of only 16%. Therefore, the functional character of these products may not be preserved if dried with hot air and the research on economically viable, less-severe drying technologies should be intensified.

► Hot-air drying kinetics of apple leathers was described by a diffusive model. ► Antioxidant capacity retention in leathers decreases at increasing air temperature. ► Potassium metabisulphite showed a protective effect at moderate air temperatures. ► The use of higher temperatures reduces quality more than it increases the drying rate. ► Alternative technologies should be tested to improve nutritional quality of leathers.

Keywords
Fruit leather; Apple; Hot-air drying; Antioxidant
First Page Preview
Effect of temperature on hot-air drying rate and on retention of antioxidant capacity in apple leathers
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Food and Bioproducts Processing - Volume 91, Issue 4, October 2013, Pages 310–318
Authors
, , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us