Professor Alan Mackie

Profile

I joined the Institute of Food Research in 1983. Since then I have worked on Interfacial layer composition, where the work was key to understanding how caseinate emulsions (common food systems) are stabilised and how that stability can be manipulated to give specific textures. Work subsequently focused on protein surfactant interactions: In particular, I was interested in understanding how the interaction between proteins and surfactant at interfaces affected colloidal stability to flocculation and coalescence. We showed that proteins and surfactants stabilise colloidal structures in different ways and that these two mechanisms are incompatible and lead to phase separation at the interface known as Orogenic displacement.

More recently I have worked on Colloidal behaviour in the GI tract where my team have shown the ability of dietary fibre to limit hydrolysis products from in vitro digested emulsions from diffusing into intestinal mucus. In this work we have used multiple particle-tracking of latex beads to reveal the microstructure of intestinal mucus. We also showed for the first time that the high negative charge imparted by bile and free fatty acids to mixed micelles and other self-assembled systems allows them to penetrate the mucus layer. Recently, I have used MRI to look at the link between gastric behaviour and physiological responses. In particular they show the importance of understanding the effects of the food matrix on rates of nutrient release. My research now uses in vitro models of gastrointestinal digestion and absorption to assess the role of food structure and dietary fibre on nutrient release, absorption and metabolism.  

In 2016 I moved to University of Leeds to continue these studies as Chair of Colloid Chemistry in the School of Food Science and Nutrition and in 2017 I was appointed Head of the School. I have over 220 peer reviewed publications with total citations of over 11,000 and an h-index of 57 (Scopus).

Research interests

Alan's principal research interest is in tailoring of food structures for improved health benefits. This involves research in the following areas:

• Using processing and formulation of protein systems to control nutrient release and regulate satiety.
• Investigating the role of fibre in the upper GI tract including interactions with bile acids and dietary phenolics, as a potential agent to alter intestinal mucus permeability and alter the transport of food components into the colon.
• Assessing structural and compostional factors affecting digestion and absorption kinetics in relation to risk factors for disease.

The laboratory is equipped for this work with: interfacial rheometers, surface tension apparatus and both static and semi-dynamic simulations of upper gastrointestinal digestion and Ussing chamber apparatus for determining mucosal interactions. In addition we will have the capability to fully analyse the products of digestion as well as assess their interactions with the intestinal mucosa.

Alan has worked with a wide range of UK sponsors including UK research councils, EU and other international funding agencies and in collaboration with a number of large national and international food companies. Potential visitors are very welcome to discuss related projects, funded for example via UK Research Councils (BBSRC and EPSRC) the European Union (e.g., EU Marie Curie schemes) or the Royal Society, etc.

Qualifications

• PhD, Colloid Chemistry, 2004, UEA
• BSc Hons Physics with electronics, 1982, UEA

Research groups and institutes

• Food Colloids and Processing
• Food Colloids and Soft Matter at Interfaces
• Novel Food Design and Processing
• Human Nutrition and Lifestyle Intervention
• Digestion and Delivery
• Functional Biopolymers for Food and Health

Current postgraduate researchers

• Muhammad Gilang Ramadhan
• Aygul Can