Process manufacturing of functional food particles from lignin-rich feed

Background: Recent research at Nottingham has demonstrated that cocoa particles and cocoa fibres may be utilised to stabilise food emulsions [1] and foams [2]. An investigation attempting to understand the interfacial activity of cocoa material has highlighted the role of lignin as surface active constituent. Utilising a lab-scale thermal process and spent coffee grounds, we have since been able to validate that presence of lignin affects the hydrophobic-lipophilic balance of the particles presenting an opportunity to tune particle properties for application. Thermal processing melts internalised lignin which then deposits onto the particle surface in the form of droplets altering surface. Alternatively, microwave processing may be utilised [3].

PhD research: The overall aim of this PhD project is to build on preliminary work and investigate process-based modification of lignin-rich feed material into functional food particles. Thermal processing and alternatively microwave processing are to be investigated as key modification processes, and the impact of process parameters and feed material on particle properties and functionality is to be quantified. Analyses will include composition, and properties relevant to and functionality as emulsifiers or Pickering particles, foam stabilisers, and hydrophobic matrix filler particles.
The specific objectives in the first year of PhD study will include selection of lignin-rich waste material; application and, where necessary, development of analytical assays for lignin quantification and particle property analysis; application and validation of small scale functionalisation processes. Specific objectives for year 2 and 3 will build on the findings of the first year.

1. Gould, J., J. Vieira, and B. Wolf, Cocoa particles for food emulsion stabilisation. Food & Function, 2013. 4(9): p. 1369-1375.
2. Gould, J., A. Doyen, and B. Wolf, Using particles to structure cake. 2015: Poster presentation @ EPSRC Centre for Innovative Manufacturing in Food
3. Hu Z., and Z. Wen, Enhancing enzymatic digestibility of switchgrass by microwave-assisted alkali pretreatment. Biochemical Engineering Journal, 2008. 38: p. 369-378.