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Influence of Thermomechanical Treatment and Ratio of β-Lactoglobulin and α-Lactalbumin on the Denaturation and Aggregation of Highly Concentrated Whey Protein Systems
The influence of thermomechanical treatment (temperature 60 °C–100 °C and shear rate 0.06 s(−1)–50 s(−1)) and mixing ratio of β-lactoglobulin (βLG) and α-lactalbumin (αLA) (5:2 and 1:1) on the denaturation and aggregation of whey protein model systems with a protein concentration of 60% and 70% (w/w...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7555948/ https://www.ncbi.nlm.nih.gov/pubmed/32872486 http://dx.doi.org/10.3390/foods9091196 |
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author | Quevedo, Maria Kulozik, Ulrich Karbstein, Heike P. Emin, M. Azad |
author_facet | Quevedo, Maria Kulozik, Ulrich Karbstein, Heike P. Emin, M. Azad |
author_sort | Quevedo, Maria |
collection | PubMed |
description | The influence of thermomechanical treatment (temperature 60 °C–100 °C and shear rate 0.06 s(−1)–50 s(−1)) and mixing ratio of β-lactoglobulin (βLG) and α-lactalbumin (αLA) (5:2 and 1:1) on the denaturation and aggregation of whey protein model systems with a protein concentration of 60% and 70% (w/w) was investigated. An aggregation onset temperature was determined at approx. 80 °C for both systems (5:2 and 1:1 mixing ratio) with a protein concentration of 70% at a shear rate of 0.06 s(−1). Increasing the shear rate up to 50 s(−1) led to a decrease in the aggregation onset temperature independent of the mixing ratio. By decreasing the protein concentration to 60% in unsheared systems, the aggregation onset temperature decreased compared to that at a protein concentration of 70%. Furthermore, two significantly different onset temperatures were determined when the shear rate was increased to 25 s(−1) and 50 s(−1), which might result from a shear-induced phase separation. Application of combined thermal and mechanical treatment resulted in overall higher degrees of denaturation independent of the mixing ratio and protein concentration. At the conditions applied, the aggregation of the βLG and αLA mixtures was mainly due to the formation of non-covalent bonds. Although the proportion of disulfide bond aggregation increased with treatment temperature and shear rate, it was higher at a mixing ratio of 5:2 compared to that at 1:1. |
format | Online Article Text |
id | pubmed-7555948 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-75559482020-10-19 Influence of Thermomechanical Treatment and Ratio of β-Lactoglobulin and α-Lactalbumin on the Denaturation and Aggregation of Highly Concentrated Whey Protein Systems Quevedo, Maria Kulozik, Ulrich Karbstein, Heike P. Emin, M. Azad Foods Article The influence of thermomechanical treatment (temperature 60 °C–100 °C and shear rate 0.06 s(−1)–50 s(−1)) and mixing ratio of β-lactoglobulin (βLG) and α-lactalbumin (αLA) (5:2 and 1:1) on the denaturation and aggregation of whey protein model systems with a protein concentration of 60% and 70% (w/w) was investigated. An aggregation onset temperature was determined at approx. 80 °C for both systems (5:2 and 1:1 mixing ratio) with a protein concentration of 70% at a shear rate of 0.06 s(−1). Increasing the shear rate up to 50 s(−1) led to a decrease in the aggregation onset temperature independent of the mixing ratio. By decreasing the protein concentration to 60% in unsheared systems, the aggregation onset temperature decreased compared to that at a protein concentration of 70%. Furthermore, two significantly different onset temperatures were determined when the shear rate was increased to 25 s(−1) and 50 s(−1), which might result from a shear-induced phase separation. Application of combined thermal and mechanical treatment resulted in overall higher degrees of denaturation independent of the mixing ratio and protein concentration. At the conditions applied, the aggregation of the βLG and αLA mixtures was mainly due to the formation of non-covalent bonds. Although the proportion of disulfide bond aggregation increased with treatment temperature and shear rate, it was higher at a mixing ratio of 5:2 compared to that at 1:1. MDPI 2020-08-29 /pmc/articles/PMC7555948/ /pubmed/32872486 http://dx.doi.org/10.3390/foods9091196 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Quevedo, Maria Kulozik, Ulrich Karbstein, Heike P. Emin, M. Azad Influence of Thermomechanical Treatment and Ratio of β-Lactoglobulin and α-Lactalbumin on the Denaturation and Aggregation of Highly Concentrated Whey Protein Systems |
title | Influence of Thermomechanical Treatment and Ratio of β-Lactoglobulin and α-Lactalbumin on the Denaturation and Aggregation of Highly Concentrated Whey Protein Systems |
title_full | Influence of Thermomechanical Treatment and Ratio of β-Lactoglobulin and α-Lactalbumin on the Denaturation and Aggregation of Highly Concentrated Whey Protein Systems |
title_fullStr | Influence of Thermomechanical Treatment and Ratio of β-Lactoglobulin and α-Lactalbumin on the Denaturation and Aggregation of Highly Concentrated Whey Protein Systems |
title_full_unstemmed | Influence of Thermomechanical Treatment and Ratio of β-Lactoglobulin and α-Lactalbumin on the Denaturation and Aggregation of Highly Concentrated Whey Protein Systems |
title_short | Influence of Thermomechanical Treatment and Ratio of β-Lactoglobulin and α-Lactalbumin on the Denaturation and Aggregation of Highly Concentrated Whey Protein Systems |
title_sort | influence of thermomechanical treatment and ratio of β-lactoglobulin and α-lactalbumin on the denaturation and aggregation of highly concentrated whey protein systems |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7555948/ https://www.ncbi.nlm.nih.gov/pubmed/32872486 http://dx.doi.org/10.3390/foods9091196 |
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