This database contains bibliographic descriptions of all Wageningen University PhD theses from 1920 onwards. It is updated on a daily basis by WUR Library.
Author abstracts and/or summaries are added to all descriptions. A link to the full text dissertation is added to the bibliographic description. In a few cases, no electronic version is available, mostly because of copyright issues.
Hard copies of all theses are available for loan at WUR Library. To request them, click the link Request this publication in the full record presentation. This is a fee based service.
Abstract: When we eat a food product, we perceive its sensory properties and subconsciously decide whether we like the food. Next to properties of flavor and taste, we perceive textural properties. How thick, rough and creamy the food is perceived depends on the structure and properties of the food product in the mouth. This thesis explores which properties of semisolid foods (mayonnaise, Dutch custard) are important for the perception of creaminess and other textural properties as well as how we can instrumentally measure these properties.
beta-lactoglobulin - whey protein - structure - ingredients - foods - fibres - physical state - food physics
Abstract: The development of new functional ingredients is important for future food products. This PhD research aimed at the development of protein based structuring agents. Structuring agents are ingredrients that can be used to tailor the texture (and the mouth-feel) of products. Proteins were transferred into protein fibres (fibrils) that are long (1 micrometer) and very thin (few nanometers). Due to their special properties, protein fibrils offer unique possibilities to mimick meat structures and make products like yoghurt more creamy. This research shows that protein fibrils can be made from different protein sources (whey protein of milk, soy protein, potato protein) by heating an acidic protein solution. Furthermore, the mechanism of fibril formation was clarified. As a result, it was possible to optimize the fibril production and control the fibril properties. Finally, an important step was made towards the application of these fibrils in food products by studying the behaviour of fibrils in a model system for food products.
Abstract: The objective of this thesis was to study fibril assembly in mixtures of whey proteins. The effect of the composition of the protein mixture on the structures and the resulting phase behaviour was investigated. The current work has shown that beta-lactoglobulin is responsible for the fibril assembly in whey protein mixtures upon heating at pH 2 and low ionic strength. To determine the efficiency of fibril formation, a method was developed to measure the conversion of whey protein monomers into fibrils. This method was used to study the effect of heating time, protein concentration, and stirring and seeding on the formation of fibrils in whey protein isolate solutions. The results have provided a better understanding of the mechanism of fibril formation and a model for fibril formation is proposed, including an activation, nucleation, growth, and termination step. Based on the method to measure the conversion two fast assays were found to determine the fibril concentration quantitatively. These two fast assays can be used for studying the kinetics of protein assembly in general, once they have been calibrated for a certain protein.
To support researchers to publish their research Open Access, deals have been negotiated with various publishers. Depending on the deal, a discount is provided for the author on the Article Processing Charges that need to be paid by the author to publish an article Open Access. A discount of 100% means that (after approval) the author does not have to pay Article Processing Charges.
For the approval of an Open Access deal for an article, the corresponding author of this article must be affiliated with Wageningen University & Research.
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.