Scientists develop healthier sausage rolls without sacrificing flaky pastry
Professor Stephen Euston and Dr Hector Mora Gallego from the School of Engineering and Physical Sciences are working with industry collaborators New Food Innovation and AB Mauri, to develop a new way to cut the saturated fat in the layered dough used in sausage rolls.
If it works, it could significantly reduce the amount of saturated fat in everyday pastries.
The team has been funded by the UK Research and Innovation Engineering and Physical Sciences Research Council (EPSRC) to reach a new milestone: moving their modified pastry from the lab into the kitchen and putting its taste to the test with real people.
You need the fat sitting between the layers of dough so that when the pastry bakes, steam forces those layers apart and gives you that flaky texture people expect. Simply replacing the fat with a healthier oil doesn’t work, because liquid oils lack the structure needed to separate the pastry layers.
Professor Stephen Euston said: “Around 10-15 million sausage rolls are sold a week in the UK, and the bestselling version contains 11 to 12.4g of saturated fat.
“That’s more than 60% of the recommended daily limit for adults.
“We want to lower the level of saturated fat while keeping the taste and texture that people love.
“We’re focused on sausage rolls, but this also applies to other baked goods that contain laminated pastry such as croissants, Danish pastries and sweet or savoury turnovers.
“Reducing the saturated fat content of these ubiquitous snacks could have a very positive impact on the nation’s health and waistlines.”
Finding new fats
Euston and his colleagues are using oleogelation, which turns liquid vegetable oils into a solid-like fat that behaves in the same way as traditional bakery fats during cooking and baking.
Professor Euston said: "Making flaky pastry is surprisingly complicated. The fat is not just there for flavour; it plays a crucial structural role in the pastry."
"You need the fat sitting between the layers of dough so that when the pastry bakes, steam forces those layers apart and gives you that flaky texture people expect.
“Simply replacing the fat with a healthier oil doesn’t work, because liquid oils lack the structure needed to separate the pastry layers.”
The Heriot-Watt team is testing whether oleogels from sunflower or rapeseed oil can mimic the behaviour of traditional solid fats while reducing the saturated fat content.
Euston said: “We’re interested in oils from crops that can be grown sustainably in the UK, in order to minimise the impact on the environment.”
Better for bakers
The scientists say bakers could also benefit from their research.
Traditional laminated pastry often has to be chilled repeatedly during production so that the fat layers do not melt as the dough is folded.
Professor Euston said: "We are hoping our oleogels will stay stable at higher temperatures, which means manufacturers may not have to chill the pastry as much.
“If we are lucky, they might not need to chill it at all."
The 10-month project is funded through an EPSRC Impact Acceleration Award. The team is working towards testing the new fats in their food industry partner’s kitchen.
Dr Andrew Bourne, UKRI ESPRC’s executive director for innovation and partnerships, said: “UKRI EPSRC’s Impact Acceleration Awards use public funding to turn promising research into practical solutions, and this project does exactly that.
“By taking innovative food science out of the lab into the kitchen and testing it with everyday consumers, it has the potential to make the nation’s favourite snacks healthier and make a genuine difference to our health and wellbeing.”
Alongside pastry, the researchers are also exploring whether the same technology could reduce saturated fat in vegan cheese alternatives.