The appeal of chocolate as an indulgent treat is partly due to the ability to process it in the molten state, allowing the combination with other ingredients and shaping into various shapes and formats.
Chocolate is a suspension of particles (cocoa, milk, sugar) in fat, and how it can be processed is influenced by its rheology. The plant-based emulsifier lecithin is often used to control its viscosity, typically in combination with synthetic emulsifiers, such as polyglycerol polyricinoleate (PGPR). This synergistic combination allows for products with sharp shapes and superior control over thickness. However, PGPR has a negative perception by consumers. The challenge for the chocolate manufacturing industry is that there is no replacement that matches PGPR performance and has better label declaration acceptance. Emulsifiers derived from natural sources such as chloroplasts, fulfilling both criteria, performance and consumer acceptance, would be ideal to have available as formulation ingredient.
The PhD project will build on preliminary data and advance the understanding of using chloroplast or lipid extracts of cocoa leaves. The aim is to develop a sustainable emulsifier system that offers all the functional benefits of PGPR in chocolate formulations. The research will involve extraction of chloroplasts and lipids from green leaves, initially working with a spinach model before validating results on cocoa leaves as a waste product of cocoa production, their physico-chemical characterisation such as composition and interfacial tension, and their impact on chocolate rheology. Finally, a sustainability assessment needs to be carried out for emulsifier systems with demonstrated functionality.
This project is funded by the BBSRC funded Food Consortium CTP and sponsored by Nestlé Product Technology Centre Confectionery York. The Food Consortium CTP comprises four major food manufacturers together with the largest UK-based independent science and technology provider and trainer for the food industry (Campden BRI), and the Haydn Green Institute (Nottingham University Business School). This industry-led collaborative programme will develop highly skilled PhD researchers and provide an innovation ecosystem through collaboration and partnership. As a successful PhD candidate, you will be part of a larger cohort of students with the opportunity to form strong links to industry and be part of a supportive network of peers, academic supervisors, industrial supervisors, and training partners.
The PhD student will be based at the School of Chemical Engineering, University of Birmingham, and collaborate with the Food Structure and Biomaterials Research Group at Nottingham’s School of Biosciences. The industrial sponsor is Nestlé Product Technology Centre Confectionery York.
For informal enquiries and to apply (including CV, cover letter, contact details for two referees and transcripts) please contact Prof Bettina Wolf @ [Email Address Removed].
Equality, Diversity and Inclusion (EDI) is fundamental to the success of the programme. The full EDI plan for the Food Consortium is available on request.