Effect of relative humidity on lipid oxidation in freezedried emulsions
DOI:
https://doi.org/10.3989/gya.2000.v51.i5.436Keywords:
Freeze-dried emulsion, Lipid, Oxidation, Relative humidity (effect of)Abstract
Oxidative stability was studied in a freeze-dried emulsion consisting of linoleic acid (LA), Tween-20, sucrose and maltodextrin in the presence of a catalyst (FeSO4/ascorbic acid). Changes in residual LA and conjugated dienes as a function of time were monitored at 0, 32, 43 and 75% relative humidities (RH). Based on GC analyses, LA oxidation was more significant in the surface fraction than the entrapped. The loss of surface oil upon storage may also be due to partial entrapment. However faster oxidation of the surface oil was confirmed by measurement of diene conjugation. Oxidation was more rapid at the lower relative humidities (0 and 32% RH) and decreased with increasing RH. At high moisture, physical modifications in the sample were observed, including reduced porosity, structural collapse, reduction of the surface oil and coalescence of oil droplets triggered by sucrose crystallization. These may be responsible for the decreased oxidation. Sucrose crystallization at the higher humidities inhibited oxidation. In addition, while samples with similar glass transition temperature (Tg) range behaved differently, samples with different glass transition range showed similar oxidative behaviour. Microstructural changes leading to oil entrapment and oil droplet coalescence were found to be significant, in this case.
Downloads
Download data is not yet available.
Downloads
Published
2000-10-30
How to Cite
1.
Ponginebbi L, Nawar WW, Chinachoti P. Effect of relative humidity on lipid oxidation in freezedried emulsions. Grasas aceites [Internet]. 2000Oct.30 [cited 2024Apr.20];51(5):348-54. Available from: https://grasasyaceites.revistas.csic.es/index.php/grasasyaceites/article/view/436
Issue
Section
Research
License
Copyright (c) 2000 Consejo Superior de Investigaciones Científicas (CSIC)
This work is licensed under a Creative Commons Attribution 4.0 International License.
© CSIC. Manuscripts published in both the printed and online versions of this Journal are the property of Consejo Superior de Investigaciones Científicas, and quoting this source is a requirement for any partial or full reproduction.All contents of this electronic edition, except where otherwise noted, are distributed under a “Creative Commons Attribution 4.0 International” (CC BY 4.0) License. You may read here the basic information and the legal text of the license. The indication of the CC BY 4.0 License must be expressly stated in this way when necessary.
Self-archiving in repositories, personal webpages or similar, of any version other than the published by the Editor, is not allowed.
