Studies on selected physicochemical properties and microstructure of β-casein-enriched ingredients for applications in formulated nutritional products

Show simple item record

dc.contributor.advisor O'Mahony, Seamus Anthony en
dc.contributor.advisor Kelly, Alan en
dc.contributor.author Li, Meng
dc.date.accessioned 2021-05-11T08:55:04Z
dc.date.available 2021-05-11T08:55:04Z
dc.date.issued 2020-09
dc.date.submitted 2020-09
dc.identifier.citation Li, M. 2020. Studies on selected physicochemical properties and microstructure of β-casein-enriched ingredients for applications in formulated nutritional products. PhD Thesis, University College Cork. en
dc.identifier.endpage 242 en
dc.identifier.uri http://hdl.handle.net/10468/11268
dc.description.abstract The milk protein β-casein (β-CN) possesses excellent functional properties and is the most abundant casein in human milk. Therefore, β-CN has the potential to be used as an ingredient in nutritional food applications, in particular in infant formulae (IF). However, the manufacture of β-CN products using various feed materials and enrichment approaches can lead to considerably differences in the overall composition and purity of β-CN in such ingredients. These differences would be expected to influence the physicochemical and functional properties of β-CN ingredients and their formulated nutritional products. This thesis presents an investigation of the physicochemical and microstructural properties of three different β-CN products (pure β-CN [β-CNpure, β-CN=90% of total protein], β-CN concentrate [β-CNconc, 80% purity], β-CN-enriched ingredient [β-CNen, 58% purity]) in different dairy systems (solutions, emulsions and model IF). The results of this work demonstrated that the three β-CN products exhibited different thermal-induced association behaviour, which was highly dependent on the purity and composition of β-CN products, along with the presence of ionic calcium and phosphates. Both β-CNpure and β-CNen showed significantly lower surface/interfacial tension compared to whey protein isolate (WPI), indicating the excellent surface-active properties of β-CN. The stability of 10% oil-in-water (O/W) emulsions stabilised with 0.5% β-CNconc was strongly dependent on the state of association of β-CN in aqueous solution. β-CNpure was covalently labelled using a fluorescent dye (NHS-Rhodamine) and the mixture of labelled β-CN and WPI (1:1 w/w) was employed as an emulsifier in O/W emulsions. Combining covalent and generic labelling techniques with confocal laser scanning microscopy (CLSM) allowed simultaneous visualisation of β-CN and WPI at the interface of oil droplets. β-CN-enriched model IF were also produced with β-CNen and WPI at various whey protein:casein ratios in the range 100:0-0:100, where the model IF enriched with β-CNen better reflected the protein profile of human milk. Increasing the proportion of β-CNen increased the stability and viscosity of IF and decreased the wettability and dispersibility of β-CNen IF powders. Overall, the findings of these studies are of relevance to end-users of β-CN-enriched products in controlling the association behaviour of β-CN and improving the stability of nutritional products enriched with β-CN. en
dc.format.mimetype application/pdf en
dc.language.iso en en
dc.publisher University College Cork en
dc.rights © 2020, Meng Li. en
dc.rights.uri https://creativecommons.org/licenses/by-nc-nd/4.0/ en
dc.subject β-casein en
dc.subject Emulsion en
dc.subject Aggregation en
dc.subject Microscopy en
dc.title Studies on selected physicochemical properties and microstructure of β-casein-enriched ingredients for applications in formulated nutritional products en
dc.type Doctoral thesis en
dc.type.qualificationlevel Doctoral en
dc.type.qualificationname PhD - Doctor of Philosophy en
dc.internal.availability Full text available en
dc.description.version Accepted Version en
dc.contributor.funder Irish Dairy Levy Research Trust en
dc.contributor.funder Teagasc Walsh Scholarship Scheme en
dc.description.status Not peer reviewed en
dc.internal.school Food and Nutritional Sciences en
dc.internal.conferring Summer 2021 en
dc.internal.ricu Food Institute en
dc.relation.project Irish Dairy Levy Research Trust (ProPart project number MDDT 6261) en
dc.contributor.advisorexternal Brodkorb, André en
dc.availability.bitstream openaccess


Files in this item

This item appears in the following Collection(s)

Show simple item record

© 2020, Meng Li. Except where otherwise noted, this item's license is described as © 2020, Meng Li.
This website uses cookies. By using this website, you consent to the use of cookies in accordance with the UCC Privacy and Cookies Statement. For more information about cookies and how you can disable them, visit our Privacy and Cookies statement