Glover, ZJ, Francis, MJ, Bisgaard, AH et al. (6 more authors) (2020) Dynamic moisture loss explored through quantitative super-resolution microscopy, spatial micro-viscosity and macroscopic analyses in acid milk gels. Food Hydrocolloids, 101. 105501. ISSN 0268-005X
Abstract
Molecular interactions and dynamic changes at a range of length scales affect the structuring of food materials, as such it is essential to explore structure at a range of different length scales. Herein, four acid milk gel samples are produced from either fresh or reconstituted skim milk that either had no heat treatment or had undergone heat treatment at 85 °C for 10 min. Milk acid gels demonstrate complex structure on a range of length scales of interest in colloidal materials and exhibit different macroscopic and water binding properties. A method is presented to measure the dynamic moisture loss in these samples, without applying external force. Super-resolution microscopy images are quantitatively analysed to describe the gel microstructure with precise features. Fluorescent Lifetime Imaging Microscopy is used to spatially resolve differences in molecular confinement across the sample's microstructure, which is quantified for each sample. Moisture loss and microstructural analyses are correlated to bulk and macroscopic properties determined through rheological and texture analysis, pH and conductivity measurements. More severe thermal and processing treatments leads to a reduction in moisture loss over time. Differences in moisture loss and mechanical properties relate to different thermal processing histories, but are not fully explained by levels of denatured whey proteins, and appear related to changes in mineral balance. The methods presented provide a comprehensive and complementary overview of material properties across relevant length scales and relevant sample conditions.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019, Elsevier. All rights reserved. This is an author produced version of an article published in Food Hydrocolloids. Uploaded in accordance with the publisher's self-archiving policy. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/. |
Keywords: | Super-resolution (STED) microscopy; Fluorescent lifetime imaging microscopy (FLIM); Dynamic moisture loss; Spatially resolved micro-viscosity; 2D spatial correlation analysis |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Food Science and Nutrition (Leeds) > FSN Colloids and Food Processing (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 07 May 2020 09:31 |
Last Modified: | 12 Nov 2020 01:39 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.foodhyd.2019.105501 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:159710 |