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Effect of homogenisation in formation of thermally induced aggregates in a non- and low- fat milk model system with microparticulated whey proteins

Torres, Isabel Celigueta; Nieto, Gema; Nylander, Tommy LU ; Simonsen, Adam Cohen; Tolkach, Alexander and Ipsen, Richard (2017) In Journal of Dairy Research 84(2). p.229-238
Abstract

The objective of the research presented in this paper was to investigate how different characteristics of whey protein microparticles (MWP) added to milk as fat replacers influence intermolecular interactions occurring with other milk proteins during homogenisation and heating. These interactions are responsible for the formation of heat-induced aggregates that influence the texture and sensory characteristics of the final product. The formation of heat-induced complexes was studied in non- and low-fat milk model systems, where microparticulated whey protein (MWP) was used as fat replacer. Five MWP types with different particle characteristics were utilised and three heat treatments used: 85 °C for 15 min, 90 °C for 5 min and 95 °C for... (More)

The objective of the research presented in this paper was to investigate how different characteristics of whey protein microparticles (MWP) added to milk as fat replacers influence intermolecular interactions occurring with other milk proteins during homogenisation and heating. These interactions are responsible for the formation of heat-induced aggregates that influence the texture and sensory characteristics of the final product. The formation of heat-induced complexes was studied in non- and low-fat milk model systems, where microparticulated whey protein (MWP) was used as fat replacer. Five MWP types with different particle characteristics were utilised and three heat treatments used: 85 °C for 15 min, 90 °C for 5 min and 95 °C for 2 min. Surface characteristics of the protein aggregates were expressed as the number of available thiol groups and the surface net charge. Intermolecular interactions involved in the formation of protein aggregates were studied by polyacrylamide gel electrophoresis and the final complexes visualised by darkfield microscopy. Homogenisation of non-fat milk systems led to partial adsorption of caseins onto microparticles, independently of the type of microparticle. On the contrary, homogenisation of low-fat milk resulted in preferential adsorption of caseins onto fat globules, rather than onto microparticles. Further heating of the milk, led to the formation of heat induced complexes with different sizes and characteristics depending on the type of MWP and the presence or not of fat. The results highlight the importance of controlling homogenisation and heat processing in yoghurt manufacture in order to induce desired changes in the surface reactivity of the microparticles and thereby promote effective protein interactions.

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organization
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type
Contribution to journal
publication status
published
subject
keywords
aggregation, heating, homogenisation, Microparticulated whey protein, protein interactions
in
Journal of Dairy Research
volume
84
issue
2
pages
10 pages
publisher
Cambridge University Press
external identifiers
  • scopus:85019623037
  • wos:000401844000019
ISSN
0022-0299
DOI
10.1017/S002202991700019X
language
English
LU publication?
yes
id
c80f4121-28bc-44d4-b1fc-89ae905b9190
date added to LUP
2017-06-13 15:41:32
date last changed
2017-09-18 11:40:40
@article{c80f4121-28bc-44d4-b1fc-89ae905b9190,
  abstract     = {<p>The objective of the research presented in this paper was to investigate how different characteristics of whey protein microparticles (MWP) added to milk as fat replacers influence intermolecular interactions occurring with other milk proteins during homogenisation and heating. These interactions are responsible for the formation of heat-induced aggregates that influence the texture and sensory characteristics of the final product. The formation of heat-induced complexes was studied in non- and low-fat milk model systems, where microparticulated whey protein (MWP) was used as fat replacer. Five MWP types with different particle characteristics were utilised and three heat treatments used: 85 °C for 15 min, 90 °C for 5 min and 95 °C for 2 min. Surface characteristics of the protein aggregates were expressed as the number of available thiol groups and the surface net charge. Intermolecular interactions involved in the formation of protein aggregates were studied by polyacrylamide gel electrophoresis and the final complexes visualised by darkfield microscopy. Homogenisation of non-fat milk systems led to partial adsorption of caseins onto microparticles, independently of the type of microparticle. On the contrary, homogenisation of low-fat milk resulted in preferential adsorption of caseins onto fat globules, rather than onto microparticles. Further heating of the milk, led to the formation of heat induced complexes with different sizes and characteristics depending on the type of MWP and the presence or not of fat. The results highlight the importance of controlling homogenisation and heat processing in yoghurt manufacture in order to induce desired changes in the surface reactivity of the microparticles and thereby promote effective protein interactions.</p>},
  author       = {Torres, Isabel Celigueta and Nieto, Gema and Nylander, Tommy and Simonsen, Adam Cohen and Tolkach, Alexander and Ipsen, Richard},
  issn         = {0022-0299},
  keyword      = {aggregation,heating,homogenisation,Microparticulated whey protein,protein interactions},
  language     = {eng},
  month        = {05},
  number       = {2},
  pages        = {229--238},
  publisher    = {Cambridge University Press},
  series       = {Journal of Dairy Research},
  title        = {Effect of homogenisation in formation of thermally induced aggregates in a non- and low- fat milk model system with microparticulated whey proteins},
  url          = {http://dx.doi.org/10.1017/S002202991700019X},
  volume       = {84},
  year         = {2017},
}