Abstract #442
Section: Milk Protein and Enzymes
Session: Milk Protein and Enzymes Symposium: Protein Interactions—Aggregations and Interfaces
Format: Oral
Day/Time: Wednesday 10:00 AM–10:30 AM
Location: 330
Presentation is being recorded
Session: Milk Protein and Enzymes Symposium: Protein Interactions—Aggregations and Interfaces
Format: Oral
Day/Time: Wednesday 10:00 AM–10:30 AM
Location: 330
Presentation is being recorded
# 442
Effect of aggregation and interfaces on the digestion of dairy proteins.
A. Mackie*1, N. Rigby1, A. Macierzanka2, 1University of Leeds, Leeds, United Kingdom, 2Gdansk University of Technology, Gdansk, Poland.
Key Words: digestion, structure, protein
Speaker Bio
Effect of aggregation and interfaces on the digestion of dairy proteins.
A. Mackie*1, N. Rigby1, A. Macierzanka2, 1University of Leeds, Leeds, United Kingdom, 2Gdansk University of Technology, Gdansk, Poland.
It is becoming clear that the role of food structure is important in digestion, nutrient absorption and health. Over the last 10 years, I have studied the effects of processing on rates and patterns of protein digestion both in vitro and in vivo. Protein digestion is governed by accessibility of the enzyme to the substrate and the removal of the hydrolysis products. Thus in principle, more structure leads to slower digestion. Using this idea, we will show that the thermal processing of whey proteins to form aggregates of different sizes can have a profound effect on the rate at which the protein can be digested in simulated gastric and intestinal phase [Macierzanka et al., Food Chemistry, 2012, 134:2156–2163]. The unfolding of proteins induced by absorption to an oil/water interface during emulsification can increase the susceptibility to digestion [Macierzanka et al., Soft Matter, 2009, 5:538–550]. In my final examples, I will show how enzymatic cross linking of proteins at interfaces using transglutaminase can alter digestion kinetics, both in vitro and in vivo [Juvonen et al., Br. J. Nutr., 2015, 114:418–429]. This latter work showed that we could successfully simulate the behavior in the GI tract, and also that the cross-linking of the protein that stabilizes the emulsions was only able to alter the digestion of proteins and had no effect on the hydrolysis of the lipid it was stabilizing.
Key Words: digestion, structure, protein
Speaker Bio
Professor Alan Mackie BSc, PhD
Chair in Colloid Chemistry
School of Food Science & Nutrition
University of Leeds
Leeds
LS2 9JT
UK
Email: a.r.mackie@leeds.ac.uk
Tel: +44 113 34 31420
My early research in food colloids was on Interfacial layer composition, where my work was key to understanding how caseinate emulsions (common food systems) are stabilised and how that stability can be manipulated to give specific textures. I subsequently focused on protein surfactant interactions: In particular I was interested in understanding how the interaction between proteins and surfactants 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. Using a combination of in vitro and in vivo studies my team have shown that thermal processing, emulsification and enzymatic cross-linking can all be used to alter the rate and patterns of dairy protein digestion. 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.
In September 2016 I moved to University of Leeds to continue these studies as chair in colloid chemistry in the School of Food Science and Nutrition. I have over 180 peer reviewed publications, Total citations (non-self) = 4743, Average citations per item = 29.4, H-index = 44.
Chair in Colloid Chemistry
School of Food Science & Nutrition
University of Leeds
Leeds
LS2 9JT
UK
Email: a.r.mackie@leeds.ac.uk
Tel: +44 113 34 31420
My early research in food colloids was on Interfacial layer composition, where my work was key to understanding how caseinate emulsions (common food systems) are stabilised and how that stability can be manipulated to give specific textures. I subsequently focused on protein surfactant interactions: In particular I was interested in understanding how the interaction between proteins and surfactants 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. Using a combination of in vitro and in vivo studies my team have shown that thermal processing, emulsification and enzymatic cross-linking can all be used to alter the rate and patterns of dairy protein digestion. 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.
In September 2016 I moved to University of Leeds to continue these studies as chair in colloid chemistry in the School of Food Science and Nutrition. I have over 180 peer reviewed publications, Total citations (non-self) = 4743, Average citations per item = 29.4, H-index = 44.
