Publicação
Development of whey protein network systems under application of moderate electric fields – Effects on protein structure and interactions
| Resumo: | This thesis describes the study of the MEF effects on protein structure and interactions, aiming at the development of whey protein network systems. For the first time MEF effects were verified in protein structure and conformation, revealing to be synergetic with thermal action and dependent of the pH of the protein solutions. MEF effects in protein structure demonstrated a linear dependence on the voltage gradients applied and were more evident at low electrical frequencies. The structural changes resultant from the electric treatment also lead to changes in protein's interactions with hydrophobic compounds, namely ANS affinity increase and retinol binding conservation. The effects of MEF in protein aggregation and gelation were accessed in WPI cold-set gels. The presence of the MEF inherent to OH contributed to the formation of smaller aggregates with lower content of reactive thiol groups and lower viscosity. The cold-set gels produced presented distinctive properties such as finer stranded structures with lower disulphide crosslinking but higher hydrophobic interactions and hydrogen bonds. These changes resulted in weaker and more elastic gel structures, with higher water retention and swelling capacity. These changes in aggregation and gel properties were potentiated by the use of higher EF strength and lower frequency treatments. As a proof of concept, the potentiality of OH and MEF application in innovative protein applications were evaluated in the production of protein-based scaffolds for tissue engineering. OH demonstrated to be an adequate technique to promote protein functionalization and to tune the scaffold´s functional properties. The variation of the EF strength during the denaturation and aggregation process resulted in scaffolds with distinctive functional properties and improved cellular proliferation. These scaffolds can be used as a support for cellular growth for tissue regeneration or as support to growing cultured meat. The effects of MEF during OH influenced the denaturation process, resulting in distinctive protein structural features and interactions. These changes at molecular level were reflected in protein aggregation, network formation and final functional properties. Therefore, an accurate selection of the MEF process variables allows controlling the functionality of protein systems, opening innovative perspectives on the use of OH and MEF not only in food and bioprocessing applications, but also in the pharmaceutical and biomedical areas. |
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| Autores principais: | Rodrigues, Rui Miguel Martins |
| Assunto: | Electric fields Gelation Protein functionality Protein structure Whey proteins Campos elétricos Estrutura de proteínas Funcionalidade proteica Gelificação Proteínas de soro |
| Ano: | 2019 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | This thesis describes the study of the MEF effects on protein structure and interactions, aiming at the development of whey protein network systems. For the first time MEF effects were verified in protein structure and conformation, revealing to be synergetic with thermal action and dependent of the pH of the protein solutions. MEF effects in protein structure demonstrated a linear dependence on the voltage gradients applied and were more evident at low electrical frequencies. The structural changes resultant from the electric treatment also lead to changes in protein's interactions with hydrophobic compounds, namely ANS affinity increase and retinol binding conservation. The effects of MEF in protein aggregation and gelation were accessed in WPI cold-set gels. The presence of the MEF inherent to OH contributed to the formation of smaller aggregates with lower content of reactive thiol groups and lower viscosity. The cold-set gels produced presented distinctive properties such as finer stranded structures with lower disulphide crosslinking but higher hydrophobic interactions and hydrogen bonds. These changes resulted in weaker and more elastic gel structures, with higher water retention and swelling capacity. These changes in aggregation and gel properties were potentiated by the use of higher EF strength and lower frequency treatments. As a proof of concept, the potentiality of OH and MEF application in innovative protein applications were evaluated in the production of protein-based scaffolds for tissue engineering. OH demonstrated to be an adequate technique to promote protein functionalization and to tune the scaffold´s functional properties. The variation of the EF strength during the denaturation and aggregation process resulted in scaffolds with distinctive functional properties and improved cellular proliferation. These scaffolds can be used as a support for cellular growth for tissue regeneration or as support to growing cultured meat. The effects of MEF during OH influenced the denaturation process, resulting in distinctive protein structural features and interactions. These changes at molecular level were reflected in protein aggregation, network formation and final functional properties. Therefore, an accurate selection of the MEF process variables allows controlling the functionality of protein systems, opening innovative perspectives on the use of OH and MEF not only in food and bioprocessing applications, but also in the pharmaceutical and biomedical areas. |
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