After nearly three years at the Riddet Institute as a postdoctoral fellow, Sophie Gallier is off to Danone Research in Utrecht, The Netherlands, to take up a role as Research Scientist. A French national, Dr Gallier says she is looking forward to being back closer to her family.
Encouraged by her supervisor, Dr David Everett at the University of Otago, to join New Zealand’s Centre of Research Excellence, Dr Gallier took up a postdoctoral position at the Riddet Institute.
“I believed that the Institute would offer me the opportunity to develop international collaborations and work with its nutrition team.”
During her time at the Institute Dr Gallier has been examining the impact of food microstructures on the digestion of natural lipids. The lipid structures under study are: walnut and almond oil bodies, and bovine milk fat globules.
“We have looked at the impact of initial food microstructures, then followed the microstructural changes in the stomach and intestine using in vitro and in vivo (rats) models,” she says.
Almond oil bodies were first studied in an aqueous dispersion system obtained by grinding almonds in water. This system was close to the bolus formed after chewing almonds. Almond oil bodies showed extensive flocculation in the stomach in vitro. The walnut study was completed with the assistance of summer student, Holly Tate.
In vitro experiments showed that walnut oil bodies flocculated and coalesced in the stomach and formed multiple emulsions in the intestine, a phenomenon that Dr Gallier had not observed before.
In her in vivo studies with bovine milk Dr Gallier showed that cream from pasteurised, homogenised milk was digested to a greater extent than creams from raw milk and pasteurised milk. The study also showed that fatty acid crystals formed in the intestine possibly due to the formation of soaps of saturated fatty acids and calcium.
Last year Dr Gallier collaborated on a project with Professor Rafael Jiménez–Flores at California State Polytechnic, building model systems to understand the changes occurring at the interface of milk fat globules under intestinal conditions.
A further human study with 42 participants is ongoing with Professor Manohar Garg at the University of Newcastle in Australia, who is also a Resident Fellow at the Riddet Institute. The study will measure postprandial effects of almonds, almond milk, almond oil and emulsified almond oil on cardiovascular risk factors. An animal study, with Dr Shane Rutherfurd of the Riddet Institute, is looking at the effect of initial microstructure on the gastric emptying rate, microstructural changes within the gastrointestinal tract and fatty acid absorption of almond oil bodies. Dr Gallier will remain involved with these projects.
So far Dr Gallier’s work has resulted in one paper on the characterisation of natural lipids, two papers on the digestion of bovine milk and cream, and two papers on the digestion of almonds and walnuts. Two reviews have been published on lipid digestion. Two book chapters and two more papers have been submitted.
Article courtesy of the Riddet Institute.
