Background
The protein content of milk and milk commodities is achieved by multiplying the analytically measured nitrogen content by a conversion factor, known as the nitrogen-to-protein conversion factor (NPCF). Total nitrogen content is most commonly determined using the Kjeldahl or Dumas methods. The most typically used NPCF for milk was proposed by Jones (1941) and was set at a figure of 6.38, meaning that milk protein is comprised of 15.67% N.
However, ambiguity on the correct conversion number arises from the fact that milk is comprised of numerous sub-protein fractions, all of which have different primary and secondary structures. The ambiguity is compounded on the basis that several proteins contain modifications to their structure aside from the basic building blocks, i.e., amino acids. Enzymatic, covalent chemical modifications of proteins typically occur after the translation of mRNAs.
These modifications include phosphorylation and glycosylation, which are assigned to certain casein protein fractions. These additional groups contribute to the overall molecular weight of proteins, which effects the ratio of total N to protein and thus effects the NPCF. Recently, some nutritionists deemed that proteins should only be defined by their amino acid profile. This excludes the covalently bound moieties, which are associated with certain amino acids within the polypeptide chain. By excluding these moieties the NPCF is reduced accordingly, effecting milk protein content and having a significant economic impact on all protein based commodities. This project will aim to determine the nitrogen content, mass of individual protein fractions, and the impact of phosphorylated, and glycosylated groups on protein functionality.
Requirements
Applications are invited from postgraduates holding or expecting a First Class Honours or Second Class Honours Grade One degree in Food Science, Chemistry, Biochemistry, Agricultural Science, Science or a related discipline.
Applicants with a relevant Masters degree are also eligible to apply. The successful candidate should be highly self-motivated and work well as part of a wider research team. Laboratory experience and experience with chromatographic or spectrometric techniques are desirable, but not essential. For applicants whose first language is not English, the English language requirements are available at https://ucc.ie/en/study/comparison/english/postgraduate/.
Award
The scholarship funding is €25,000 per annum, which includes University fees of up to a maximum of €6,000 per annum (candidate paid a flat rate stipend of €19,000 per annum) and is tenable for 4 years.
Further information
There will be a requirement and opportunities throughout the programme for professional development training and international conference attendance. It is envisaged that the successful candidate will begin January 2024 and will be primarily based at Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland under the supervision of:
- Dr Noel McCarthy, Teagasc.
- Email: noel. mccarthy @teagasc.ie
- Phone: +353 2542202
- Dr. Tom O'Callaghan,
- School of Food and Nutritional Sciences, University College Cork, Cork.
- Email: tom_ocallaghan@ucc.ie
- Phone: +353 21 4902762.
The project is also in collaboration with Prof. Thom Huppertz, FrieslandCampina Innovation Centre, Wageningen, The Netherlands.
Application procedure
Applicants should submit a cover letter and curriculum vitae detailing relevant qualifications, experience and contact details for at least one academic referee with the subject line “Dairy protein PhD application” to Dr Noel McCarthy (noel.mccarthy @teagasc.ie) cc’'ing Dr Tom O'Callaghan (tom ocallaghan@ucc.ie) by 3" of November 2023. Interviews are expected to take place in mid-December 2023 (In-person and online options will be available for interview) with an intention to start the PhD in January, 2024.
Closing date
34 November 2023
You can find the call to application here
