An estimated 10 to 15 million sausage rolls are sold in the UK every week – but a single one can contain more than 60% of an adult’s recommended daily intake of saturated fat. Now researchers at Heriot-Watt University in Edinburgh are developing a new way to make the puff pastry that could significantly cut that fat while preserving the distinctive flaky texture and taste.
The team, led by Professor Stephen Euston from the School of Engineering and Physical Sciences, is focusing on a process called oleogelation. This turns healthier liquid oils – such as sunflower or rapeseed oil, which are low in saturated fat – into a solid-like fat that can mimic the structural role of traditional solid fats in pastry. The goal is to replace the high-saturated-fat butters and margarines currently used in laminated pastries like sausage rolls, croissants, Danish pastries and turnovers without compromising on the eating experience.
“Explains the science behind making sausage rolls healthier while keeping the flaky pastry”
The science behind the flaky pastry is surprisingly intricate. As Professor Euston explains, the fat is not just there for flavour; it plays a crucial structural role. In laminated dough, the fat sits between thin layers of dough. When the pastry bakes, steam from the water in the dough forces those layers apart, creating the light, flaky texture people expect. Liquid oils lack the structure needed to separate the layers effectively, so simply swapping the fat for a healthier oil doesn’t work. Oleogelation, however, uses a gel network to give liquid oils the solid-like properties required.
The research also has potential benefits for manufacturers. Traditional laminated pastry often needs to be chilled repeatedly during production to stop the fat layers from melting as the dough is folded. The oleogels the team is developing may stay stable at higher temperatures, reducing or even eliminating the need for chilling – which could save energy and simplify production.
Why does this matter for UK readers? Sausage rolls are a staple of British convenience food, from bakeries to petrol stations. If the research succeeds, it could lead to healthier versions of not only sausage rolls but also other popular pastries, making it easier for people to enjoy these treats without exceeding saturated fat guidelines. The team is also focusing on oils from crops that can be grown in the UK, which would minimise the environmental impact of importing tropical oils.
Q: What is oleogelation? Oleogelation is a process that turns liquid oils into a solid-like fat using a gelling agent. This allows healthier oils, which are lower in saturated fat, to behave like traditional solid fats in pastry, providing the necessary structure for flaky layers.
Q: Will healthier sausage rolls taste the same? The researchers at Heriot-Watt are specifically aiming to keep both the taste and the texture that people love. They are using a type of oleogel that mimics the behaviour of traditional fats, so the final product should be indistinguishable from a standard sausage roll.
Q: When will these healthier sausage rolls be available? The project is a 10-month research effort, so any commercial product is likely several years away. The team first needs to perfect the oleogel recipe, then scale up production and ensure food safety and regulatory approval before bakeries can adopt the technology.
What happens next: The Heriot-Watt team is continuing its 10-month study, with the aim of developing a practical oleogel that can be used in industrial pastry production. If successful, the process could be applied across the baking industry, potentially changing the nutritional profile of many of the UK’s most popular pastries.