An opportunity to advance the fundamental understanding of lipid crystallization.
Crystallization and polymorphism under flow in cocoa butter blends
Prof Malcolm Povey and Prof Michael Rappolt, University of Leeds, School of Food Science and Nutrition Industrial Partner: Nestlé Product Technology Centre, York
OUTLINE
Chocolate bloom is a whitish coating that can appear on the surface of chocolate, resulting in an unappetizing appearance and texture. This effect is one of the main concerns in the production of chocolate. When vegetable oils are blended with cocoa butter, the usual, albeit very complicated polymorphic behavior is altered in ways, which may lead to the appearance of unsightly bloom in chocolate. This could be due to phase separation processes such as compound crystallization or to other, unknown causes.
We propose to study the fundamentals of the crystal nucleation and growth in cocoa butter and its blends by SAXS/WAXS and ultrasound spectroscopy using a flow cell specially designed for use with the SAXSPACE instrument in our laboratory. The impact of various vegetable oil blends on cocoa butter crystallization will be followed through the evolution of diffraction pattern as a function of time and temperature, using pure cocoa butter as a baseline for comparison. If the preliminary data at Leeds justifies it, a case may also be made for beam time at the Diamond Synchrotron and other intense X-ray facilities. The student will gain real-world industrial research experience from the collaboration between Leeds and Nestlé as part of a wider effort to enlarge the range of fats and vegetable oils available to chocolate and confectionary manufacture, hence improving diet and health of consumers.
The PhD supervisors will be the project proposers Prof Malcolm Povey and Professor Michael Rappolt (Academic) and Dr Josélio Vieira (Industrial); however we expect to collaborate also with Dr Xiaojun Lai (SPEME), X-ray diffraction, and Dr Johan Mattsson (Physics), DSC. We will locate the project as part of Professor Fiona Meldrum’s Crystallization Centre (www.crystals.leeds.ac.uk) and the student will benefit from being part of a large group of research students working in a number of faculties across the university with regular seminars and invited speakers.
The project objective is to gain a better understanding of edible fat crystal nucleation and growth in cocoa butter blends.
This is a four year BBSRC CASE studentship with fees and maintenance support (Stipend £19,206.50 pa) to UK residents. Due to funding restrictions, the full studentship is open to UK/EU applicants who meet BBSRC’s studentship eligibility criteria - seehttp://www.bbsrc.ac.uk/web/FILES/Guidelines/studentship_eligibility.pdf. UK/EU candidates who do not meet BBRSC’s residency requirements will only qualify for tuition fees and industrial supplement, not the full studentship.
This is cutting edge research and the candidate must have at least an upper second science honours degree or equivalent, preferably in the physical sciences or engineering, although enthusiastic candidates with other science degrees will be seriously considered. The candidate will join a lively and expanding research group leading in the application of food physics to industrial problems of national importance. The group established its international reputation through the application of ultrasound and acoustics to the measurement and control of food processing operations. The recent appointment of a Leadership Chair in Lipid Biophysics and the acquisition of a SAXSPACE SAXS/WAXS X-ray diffraction instrument supports this work.
Applications:
Enquiries, should be directed to Prof Malcolm Povey, School of Food Science and Nutrition, University of Leeds (01133432963). We expect the studentship to begin in January 2015 but there is some flexibility in the starting date.
<input type="text" class="email-value js-email-value" id="email-value" readonly="readonly" value="University_of_Leeds-idl3ap-827049@jobs.researchgate.net" style="margin: 0px; font-size: 12px; vertical-align: middle; outline: 0px; padding: 3px; cursor: text; width: 384px; border-style: none; font-weight: bold; color: rgb(68, 68, 68); box-shadow: none; -webkit-transition: all 0.1s linear; transition: all 0.1s linear; background-image: initial; background-attachment: initial; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial; " />