Using phenolphthalein as a promising indicator to monitor the vacuum freeze-drying process

To improve the quality of the product, an important subject in vacuum freeze-drying process is to accurately monitor the state of water at its freezing stage and that of the residual water at its drying stage. In this paper, an easy-to-perform method is shown to monitor the state of water during the...

Full description

Saved in:
Bibliographic Details
Published inMaterials letters Vol. 139; pp. 245 - 248
Main Authors Liu, Lin, Wang, Ya, Fan, Daidi, Mi, Yu
Format Journal Article
LanguageEnglish
Published 15.01.2015
Subjects
Color
Colour
Drying
Freezing
Hydrogen bonding
Monitors
Phenolphthalein
Online AccessGet full text
ISSN0167-577X
DOI10.1016/j.matlet.2014.10.047

Cover

More Information
Summary:To improve the quality of the product, an important subject in vacuum freeze-drying process is to accurately monitor the state of water at its freezing stage and that of the residual water at its drying stage. In this paper, an easy-to-perform method is shown to monitor the state of water during the whole freeze-drying process (i.e. the state of water in the freezing stage and that of the residual water in drying stage) based on colour changes of phenolphthalein. A sample prepared with phenolphthalein was sensitive to structural changes of water hydrogen bonding network and exhibited colour-changing effect. This makes it possible to accurately trace the dynamic freeze-drying process, thus providing a valuable tool for preparing high-quality products.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0167-577X
DOI:10.1016/j.matlet.2014.10.047