Fatty formulation may boost feeling of fullness
Consumption of the acid-stable emulsion reportedly increased feeling of fullness, decreased hunger, and decreased appetite, compared to an acid-unstable emulsion, scientists from the University of Nottingham report in the British Journal of Nutrition.
"Our research proves it is possible to design oil-in-water emulsions with different behaviours in the gut to influence gastrointestinal physiology and, ultimately, satiety," said lead author Dr Luca Marciani.
Acid-stable emulsions were formulated using olive oil and water and stabilised using the commonly used food-grade emulsifier polyoxyethylene sorbitan monostearate (Tween 60, E491, from Macphie, UK).
"This formulation could be used as an ingredient in new foods to make them more filling, which in turn could help reduce overconsumption of calories," said co-researcher Dr Martin Wickham from the Institute of Food Research.
Dr Wickham told FoodNavigator that the research is at a very early stage and a long way from commercialisation. He added that food manufacturer would probably not be able to use the formulation currently.
Satiety is seen as a key target in the battle against obesity, with figures from Europe showing that up to 27 per cent of men, 38 per cent of women, and 3 million children are clinically obese in some parts of the bloc.
Foods marketed for satiety enhance feelings of fullness after eating, acting as a boost to a person's will-power and helping them avoid a reversion to old habits in a bid to stave off hunger pangs, or 'grazing' in between meals.
Study details
The Nottingham-based researchers recruited 11 healthy male volunteers with an average age of 24 and an average BMI of 23.8 kg/m2, and, on two separate occasions, fed them 500 ml of an acid-stable or unstable emulsion containing 15 per cent palmitate-enriched olive oil-in-water emulsion meals. The acid-unstable emulsion employed sorbitan monooleate (Span 80, E494; Esterchem Ltd, UK) as the emulsifier.
The volunteers' stomachs were imaged in real time until they looked empty using an ultra-fast type of MRI scanning called echo-planar imaging.
The unstable emulsion was found to quickly separate into water and fat and the droplets coalesce. This resulted in a rapid emptying of the stomach and after one hour the volume was nearly half that of the stable meal.
On the other hand, the acid-stable emulsion did not separate, and the average time for half of the stomach to empty was almost three times that as for the acid-unstable emulsion (185 versus 67 minutes, respectively).
Furthermore, self-reported feelings of satiety increased in the acid-stable emulsion group, while hunger appetite decreased.
“The present study found that the intragastric behaviour of fat emulsions influences the subsequent sensations of satiety. We found that the acid-stable emulsion meal made subjects feel fuller, less hungry and have less appetite compared with the acid-unstable emulsion meal,” wrote the researchers in the BJN.
The retail market for weight management products was estimated by Euromonitor International to be worth US$0.93bn (€0.73) in Europe in 2005 and $3.93bn in the US, indicating that call to slim down or face the health consequences is being heeded by a slice of the overweight population at least.
The study was funded by the Biotechnology and Biological Sciences Research Council.
Source: British Journal of Nutrition Volume 101, Issue 06, Pages 919-928, doi: 10.1017/S0007114508039986“Effect of intragastric acid stability of fat emulsions on gastric emptying plasma lipid profile and postprandial satiety” Authors: L. Marciani, R. Faulks, M.S.J. Wickham, D. Bush, B. Pick, J. Wright, E.F. Cox, A. Fillery-Travis, P.A. Gowland, R.C. Spiller
