Staff View: Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures

Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures

Freeze-drying is an energy intensive unit operation used for the production of dehydrated foods, such as instant coffee and dried fruits, and results in high sensorial, nutritional and reconstitution properties of the final products. Understanding the relationships between operating conditions and p...

Full description

Saved in:

Bibliographic Details
Main Authors:	Malik, N., Muttakin, S., Lopez-Quiroga, E., Watson, N.J., Fryer, P.J., Bakalis, S., Gouseti, O.
Format:	Article
Language:	English
Published:	Elsevier 2020
Subjects:	T Technology (General) TP368-456 Food processing and manufacture
Online Access:	http://eprints.uthm.edu.my/5085/1/AJ%202020%20%2885%29.pdf http://eprints.uthm.edu.my/5085/ https://doi.org/10.1016/j.foodhyd.2020.105712
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my.uthm.eprints.5085
record_format	eprints
spelling	my.uthm.eprints.50852022-01-05T05:35:37Z http://eprints.uthm.edu.my/5085/ Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures Malik, N. Muttakin, S. Lopez-Quiroga, E. Watson, N.J. Fryer, P.J. Bakalis, S. Gouseti, O. T Technology (General) TP368-456 Food processing and manufacture Freeze-drying is an energy intensive unit operation used for the production of dehydrated foods, such as instant coffee and dried fruits, and results in high sensorial, nutritional and reconstitution properties of the final products. Understanding the relationships between operating conditions and product quality is essential to design processes that are energy efficient, whilst producing high quality dried foods. In this work, the properties (microstructure and reconstitution) of freeze-dried gum arabic samples (with initial concentrations ranging between 20 and 60% solids by weight) were evaluated. The materials were dried at three different primary drying shelf temperatures, Ts (- 20, - 30 and - 40 ◦C). Sample temperatures recorded throughout freeze-drying were close to the pre-set Ts, with the exception of the 60% initial concentration system, where the sample was hotter than the shelf by 10–15 ◦C, in particular on increasing Ts. This was attributed to a combination of local temperature and pressure conditions that may have resulted in partial melting of the material. For the 20–50% systems, the properties of the freeze-dried materials were mainly affected by the initial concentration of the system, with increasing initial concentration generally resulting in lower porosities (ranging between 20 and 40%) and higher reconstitution times (ranging between 0.5 and 10min for 95% reconstitution). Pores were generally needle-shaped and <200 μm. Large (200–1800 μm), circular pores were observed in high initial concentration systems, and they were dominant in the microstructure of the freeze-dried 60% sample. The presence of these large bubbles was linked to the partial melting of the material, which enabled its expansion and puffing. For the 60% system, primary drying temperature had a profound effect on the properties of the freeze-dried solid, with samples dried at higher temperature showing higher porosity (e.g. 60–70% for Ts = -¬¬ 20◦C) and faster reconstitution rates (e.g. 3min for 95% reconstitution at Ts = - 20◦C). Overall, this study demonstrates the significance of formulation and shelf temperature on the porous structure of freeze-dried samples, which directly influences product performance. Elsevier 2020 Article PeerReviewed text en http://eprints.uthm.edu.my/5085/1/AJ%202020%20%2885%29.pdf Malik, N. and Muttakin, S. and Lopez-Quiroga, E. and Watson, N.J. and Fryer, P.J. and Bakalis, S. and Gouseti, O. (2020) Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures. Food Hydrocolloids, 104. pp. 1-11. ISSN 0268-005X https://doi.org/10.1016/j.foodhyd.2020.105712
institution	Universiti Tun Hussein Onn Malaysia
building	UTHM Library
collection	Institutional Repository
continent	Asia
country	Malaysia
content_provider	Universiti Tun Hussein Onn Malaysia
content_source	UTHM Institutional Repository
url_provider	http://eprints.uthm.edu.my/
language	English
topic	T Technology (General) TP368-456 Food processing and manufacture
spellingShingle	T Technology (General) TP368-456 Food processing and manufacture Malik, N. Muttakin, S. Lopez-Quiroga, E. Watson, N.J. Fryer, P.J. Bakalis, S. Gouseti, O. Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures
description	Freeze-drying is an energy intensive unit operation used for the production of dehydrated foods, such as instant coffee and dried fruits, and results in high sensorial, nutritional and reconstitution properties of the final products. Understanding the relationships between operating conditions and product quality is essential to design processes that are energy efficient, whilst producing high quality dried foods. In this work, the properties (microstructure and reconstitution) of freeze-dried gum arabic samples (with initial concentrations ranging between 20 and 60% solids by weight) were evaluated. The materials were dried at three different primary drying shelf temperatures, Ts (- 20, - 30 and - 40 ◦C). Sample temperatures recorded throughout freeze-drying were close to the pre-set Ts, with the exception of the 60% initial concentration system, where the sample was hotter than the shelf by 10–15 ◦C, in particular on increasing Ts. This was attributed to a combination of local temperature and pressure conditions that may have resulted in partial melting of the material. For the 20–50% systems, the properties of the freeze-dried materials were mainly affected by the initial concentration of the system, with increasing initial concentration generally resulting in lower porosities (ranging between 20 and 40%) and higher reconstitution times (ranging between 0.5 and 10min for 95% reconstitution). Pores were generally needle-shaped and <200 μm. Large (200–1800 μm), circular pores were observed in high initial concentration systems, and they were dominant in the microstructure of the freeze-dried 60% sample. The presence of these large bubbles was linked to the partial melting of the material, which enabled its expansion and puffing. For the 60% system, primary drying temperature had a profound effect on the properties of the freeze-dried solid, with samples dried at higher temperature showing higher porosity (e.g. 60–70% for Ts = -¬¬ 20◦C) and faster reconstitution rates (e.g. 3min for 95% reconstitution at Ts = - 20◦C). Overall, this study demonstrates the significance of formulation and shelf temperature on the porous structure of freeze-dried samples, which directly influences product performance.
format	Article
author	Malik, N. Muttakin, S. Lopez-Quiroga, E. Watson, N.J. Fryer, P.J. Bakalis, S. Gouseti, O.
author_facet	Malik, N. Muttakin, S. Lopez-Quiroga, E. Watson, N.J. Fryer, P.J. Bakalis, S. Gouseti, O.
author_sort	Malik, N.
title	Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures
title_short	Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures
title_full	Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures
title_fullStr	Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures
title_full_unstemmed	Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures
title_sort	microstructure and reconstitution of freeze-dried gum arabic at a range of concentrations and primary drying temperatures
publisher	Elsevier
publishDate	2020
url	http://eprints.uthm.edu.my/5085/1/AJ%202020%20%2885%29.pdf http://eprints.uthm.edu.my/5085/ https://doi.org/10.1016/j.foodhyd.2020.105712
_version_	1738581334437134336
score	13.211869

Microstructure and reconstitution of freeze-dried gum Arabic at a range of concentrations and primary drying temperatures

Similar Items