Advanced

Microscopic studies providing insight into the mechanisms of mass transfer in vacuum impregnation

Panarese, Valentina; Dejmek, Petr LU ; Rocculi, Pietro and Gomez, Federico LU (2013) In Innovative Food Science & Emerging Technologies 18. p.169-176
Abstract
A microscopic method was developed to detect pressure thresholds for gas outflow and solution impregnation during vacuum impregnation of plant materials. Raw materials with different porosities (apple and spinach) were impregnated with an isotonic sucrose solution at a minimum pressure of 150 mbar. An automatic vacuum controller system (AVCS) was used to control the pressure during vacuum impregnation. Micrographs of tissues subjected to vacuum impregnation were recorded as the pressure in the treatment chamber was varied. Image analysis allowed the evaluation of the pressure at which gas was released from the pores (seen as bubbles) during the application of vacuum, and the pressure at which tissue impregnation took place during the... (More)
A microscopic method was developed to detect pressure thresholds for gas outflow and solution impregnation during vacuum impregnation of plant materials. Raw materials with different porosities (apple and spinach) were impregnated with an isotonic sucrose solution at a minimum pressure of 150 mbar. An automatic vacuum controller system (AVCS) was used to control the pressure during vacuum impregnation. Micrographs of tissues subjected to vacuum impregnation were recorded as the pressure in the treatment chamber was varied. Image analysis allowed the evaluation of the pressure at which gas was released from the pores (seen as bubbles) during the application of vacuum, and the pressure at which tissue impregnation took place during the restoration of atmospheric pressure. Spinach tissues showed gas release at a much lower pressure than apple, and impregnation commenced at a much higher pressure. These differences in pressure threshold could be caused by the narrow pores in spinach and possibly by changes in leaf volume. Industrial relevance: Vacuum impregnation is considered a promising technology to facilitate the impregnation of vegetable tissues with different solutions containing, e.g., firming, antioxidant or antimicrobial agents. The mass transfer taking place during vacuum impregnation depends on the characteristics of the tissue pores. Effective vacuum impregnation requires the efficient removal of air from the tissue during vacuum treatment to obtain complete filling of the tissue during the subsequent impregnation step. The findings of this study may allow food manufacturers to optimize vacuum impregnation parameters depending on the porosity characteristics of the raw material. (C) 2013 Elsevier Ltd. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Vacuum impregnation, Porosity, Capillary pressure, Pressure thresholds
in
Innovative Food Science & Emerging Technologies
volume
18
pages
169 - 176
publisher
Elsevier
external identifiers
  • wos:000319237000023
  • scopus:84876724270
ISSN
1466-8564
DOI
10.1016/j.ifset.2013.01.008
language
English
LU publication?
yes
id
d7e02177-5a16-434e-8b50-ac87e74176f1 (old id 3932285)
date added to LUP
2013-07-15 13:37:09
date last changed
2019-03-05 02:31:59
@article{d7e02177-5a16-434e-8b50-ac87e74176f1,
  abstract     = {A microscopic method was developed to detect pressure thresholds for gas outflow and solution impregnation during vacuum impregnation of plant materials. Raw materials with different porosities (apple and spinach) were impregnated with an isotonic sucrose solution at a minimum pressure of 150 mbar. An automatic vacuum controller system (AVCS) was used to control the pressure during vacuum impregnation. Micrographs of tissues subjected to vacuum impregnation were recorded as the pressure in the treatment chamber was varied. Image analysis allowed the evaluation of the pressure at which gas was released from the pores (seen as bubbles) during the application of vacuum, and the pressure at which tissue impregnation took place during the restoration of atmospheric pressure. Spinach tissues showed gas release at a much lower pressure than apple, and impregnation commenced at a much higher pressure. These differences in pressure threshold could be caused by the narrow pores in spinach and possibly by changes in leaf volume. Industrial relevance: Vacuum impregnation is considered a promising technology to facilitate the impregnation of vegetable tissues with different solutions containing, e.g., firming, antioxidant or antimicrobial agents. The mass transfer taking place during vacuum impregnation depends on the characteristics of the tissue pores. Effective vacuum impregnation requires the efficient removal of air from the tissue during vacuum treatment to obtain complete filling of the tissue during the subsequent impregnation step. The findings of this study may allow food manufacturers to optimize vacuum impregnation parameters depending on the porosity characteristics of the raw material. (C) 2013 Elsevier Ltd. All rights reserved.},
  author       = {Panarese, Valentina and Dejmek, Petr and Rocculi, Pietro and Gomez, Federico},
  issn         = {1466-8564},
  keyword      = {Vacuum impregnation,Porosity,Capillary pressure,Pressure thresholds},
  language     = {eng},
  pages        = {169--176},
  publisher    = {Elsevier},
  series       = {Innovative Food Science & Emerging Technologies},
  title        = {Microscopic studies providing insight into the mechanisms of mass transfer in vacuum impregnation},
  url          = {http://dx.doi.org/10.1016/j.ifset.2013.01.008},
  volume       = {18},
  year         = {2013},
}