{"id":{"repo_id":"cork","oai_identifier":"oai:cora.ucc.ie:10468/11268"},"canonical_url":"https://search.dev.ndltd.org/etd/cork/oai:cora.ucc.ie:10468/11268","repository":{"repo_id":"cork","name":"University College Cork","base_url":"https://cora.ucc.ie/server/oai/request"},"display":{"title":"Studies on selected physicochemical properties and microstructure of β-casein-enriched ingredients for applications in formulated nutritional products","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.","abstract_html":"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.","abstract_has_math":false,"creators":["Li, Meng"],"institution":"University College Cork","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["O'Mahony, Seamus Anthony","Kelly, Alan"],"committee_chairs":[],"committee_members":[],"year":2020,"date_issued":"2020-09","date_published":"2020-09","updated_at":"2026-07-24T01:48:42Z","subjects":["β-casein","Emulsion","Aggregation","Microscopy"],"languages":["en"],"rights":["© 2020, Meng Li."],"rights_urls":["https://creativecommons.org/licenses/by-nc-nd/4.0/"],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/10468/11268","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["O'Mahony, Seamus Anthony","Kelly, Alan"]},{"key":"dc:creator","label":"Author","values":["Li, Meng"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2021-05-11T08:55:04Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2021-05-11T08:55:04Z"]},{"key":"dc:date.issued","label":"Date","values":["2020-09"]},{"key":"dc:publisher","label":"Institution","values":["University College Cork"]},{"key":"dc:type","label":"Dc Type","values":["Doctoral thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["PhD - Doctor of Philosophy"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["β-casein","Emulsion","Aggregation","Microscopy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["© 2020, Meng Li."]},{"key":"dc:rights.uri","label":"Rights URI","values":["https://creativecommons.org/licenses/by-nc-nd/4.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10468/11268"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["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."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Studies on selected physicochemical properties and microstructure of β-casein-enriched ingredients for applications in formulated nutritional products"]}]}],"canonical_facts":{"dc:contributor.advisor":["O'Mahony, Seamus Anthony","Kelly, Alan"],"dc:creator":["Li, Meng"],"dc:date.accessioned":["2021-05-11T08:55:04Z"],"dc:date.available":["2021-05-11T08:55:04Z"],"dc:date.issued":["2020-09"],"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."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["https://hdl.handle.net/10468/11268"],"dc:language.iso":["en"],"dc:publisher":["University College Cork"],"dc:rights":["© 2020, Meng Li."],"dc:rights.uri":["https://creativecommons.org/licenses/by-nc-nd/4.0/"],"dc:subject":["β-casein","Emulsion","Aggregation","Microscopy"],"dc:title":["Studies on selected physicochemical properties and microstructure of β-casein-enriched ingredients for applications in formulated nutritional products"],"dc:type":["Doctoral thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["PhD - Doctor of Philosophy"]},"updated_at":"2026-07-24T01:48:42Z"}