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Study of phase separated food-inks by oral tribology assessment and molecular dynamics modelling

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Resumo:The incorporation of dairy products in food is widely used worldwide as a source of important nutrients in human food. It has kept pace with technological development over the years as its consumption increases. Milk proteins and whey proteins, in particular, exhibit high nutritional values, contributing to many functional properties of food formulations. Despite these properties, with the incorporation of these proteins there is a concern related to the perception of astringency, which is roughly characterized by an unpleasant oral sensation (dry mouth), although it is a more complex phenomenon. In this study, we intend to highlight the mechanisms responsible for the oral astringency phenomenon, conducting tribological tests and later experimental validation by atomistic computational simulations (molecular dynamics), to characterize the friction and lubrication behaviour of 3 systems: food (whey proteins), polysaccharides (gellan gum) and mucins. Tribological tests were performed in a ball-on-disk configuration, lubricated by artificial saliva and mucins, subjected to a 1N force. To plan the samples to be tested, to quantify the influence of the studied variables and their correlation on friction and lubrication behaviour, a statistical design tool (DOE) was used. All assays were followed with microscopy techniques (SEM, AFM, CLSM). For simulation, we used molecular dynamics (MD) with the code LAMMPS and the visualization of atomic trajectories with OVITO. MD simulation was used to model the system tribe studied, in order to observe the mechanisms underlying the nanometer scale under conditions equivalent to macroscopic assays. Regarding the results obtained, samples of WPI, GG and mucins produced revealed that it is possible to establish a correlation between the various techniques used. The information obtained from these tools provides relevant data for astringency measurement and subsequently enables the production of foods (dairy products) that may reduce this mouthfeel, in the future.
Autores principais:Pires, Mariana Araújo
Assunto:Astringency Friction Molecular dynamics Perception Statistical design tool Adstringência Atrito Desenho experimental Dinâmica molecular Perceção Engenharia e Tecnologia::Engenharia Médica
Ano:2020
País:Portugal
Tipo de documento:dissertação de mestrado
Tipo de acesso:acesso aberto
Instituição associada:Universidade do Minho
Idioma:inglês
Origem:RepositóriUM - Universidade do Minho
Descrição
Resumo:The incorporation of dairy products in food is widely used worldwide as a source of important nutrients in human food. It has kept pace with technological development over the years as its consumption increases. Milk proteins and whey proteins, in particular, exhibit high nutritional values, contributing to many functional properties of food formulations. Despite these properties, with the incorporation of these proteins there is a concern related to the perception of astringency, which is roughly characterized by an unpleasant oral sensation (dry mouth), although it is a more complex phenomenon. In this study, we intend to highlight the mechanisms responsible for the oral astringency phenomenon, conducting tribological tests and later experimental validation by atomistic computational simulations (molecular dynamics), to characterize the friction and lubrication behaviour of 3 systems: food (whey proteins), polysaccharides (gellan gum) and mucins. Tribological tests were performed in a ball-on-disk configuration, lubricated by artificial saliva and mucins, subjected to a 1N force. To plan the samples to be tested, to quantify the influence of the studied variables and their correlation on friction and lubrication behaviour, a statistical design tool (DOE) was used. All assays were followed with microscopy techniques (SEM, AFM, CLSM). For simulation, we used molecular dynamics (MD) with the code LAMMPS and the visualization of atomic trajectories with OVITO. MD simulation was used to model the system tribe studied, in order to observe the mechanisms underlying the nanometer scale under conditions equivalent to macroscopic assays. Regarding the results obtained, samples of WPI, GG and mucins produced revealed that it is possible to establish a correlation between the various techniques used. The information obtained from these tools provides relevant data for astringency measurement and subsequently enables the production of foods (dairy products) that may reduce this mouthfeel, in the future.