Drying characteristics and quality of grape under physical pretreatment

Adiletta, G. and Russo, P. and Senadeera, W. and Di Matteo, M. (2016) Drying characteristics and quality of grape under physical pretreatment. Journal of Food Engineering, 172. pp. 9-18. ISSN 0260-8774

Abstract

Grape drying is a slow and energy intensive process because the waxy peel has low permeability to moisture. Therefore, peel chemical and physical pretreatments are considered before drying in order to facilitate water diffusion. However, they cause heterogeneity in the waxes removal and problems during shelf-life.

In this paper an alternative abrasive pretreatment of grape peel, for enhancing the drying rate and preserving the samples, was applied to Red Globe grapes. Convective drying experiments were carried out at 40–70 °C and at 2.3 ms−1 air velocity. The effect of wax abrasive pretreatment on the drying kinetics and quality parameters of raisins was investigated. The results were compared with those of samples pretreated by dipping in alkaline ethyl oleate solution and untreated grapes. All the dried samples are darker than fresh one and shrunked. The samples pretreated by peel abrasion and dried at 50 °C showed the lowest color changes, less shrinkage and the best rehydration capacity. The drying kinetics and shrinkage curves were also analyzed using some commonly available empirical models.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to Published version due to publisher copyright policy.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering
Date Deposited: 22 Feb 2017 06:05
Last Modified: 22 Feb 2017 23:09
Uncontrolled Keywords: grape; drying; abrasive pretreatment; antioxidant activity; shrinkage; empirical models
Fields of Research : 09 Engineering > 0908 Food Sciences > 090802 Food Engineering
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970109 Expanding Knowledge in Engineering
Identification Number or DOI: 10.1016/j.jfoodeng.2015.06.031
URI: http://eprints.usq.edu.au/id/eprint/30527

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