Scientists attempt to enhance nutritional value of sausage rolls while keeping pastry’s flakiness
Scientists at Heriot-Watt University in Edinburgh are developing a method to reduce the saturated fat content of Britain’s beloved sausage roll without compromising its signature flaky pastry. The research, which centres on a process known as oleogelation, aims to tackle the health toll exacted by one of the nation’s most popular snacks.
The health problem
An estimated 10 to 15 million sausage rolls are sold in the UK every week, but a single roll can contain more than 60% of an adult’s recommended daily saturated fat intake. High consumption of saturated fat is linked to elevated LDL cholesterol – the “bad” kind – and is a major risk factor for heart disease. To put the numbers in perspective, a typical Greggs sausage roll (103g) contains around 348 calories, 24g of fat (of which 11g is saturates) and 1.5g of salt. An M&S British sausage roll supplies about 122 calories and 5g of saturates. UK health guidelines advise that men should consume no more than 30g of saturated fat per day and women no more than 20g. Pastries as a category contribute roughly 10% of the UK’s total saturated fat intake.
How oleogelation works
The puff pastry used in sausage rolls and other laminated baked goods relies on solid fat for its distinctive flaky texture. The research team, led by Professor Stephen Euston of Heriot-Watt’s School of Engineering and Physical Sciences, is trying to replace those solid fats with healthier liquid oils such as sunflower or rapeseed oil, which are lower in saturated fat. The challenge is that liquid oils cannot perform the same structural role. “Simply replacing the fat with a healthier oil doesn’t work, because liquid oils lack the structure needed to separate the pastry layers,” Professor Euston explained.
The solution lies in oleogelation, a technique that transforms liquid oils into a “solid-like fat” using structuring agents. The resulting oleogel is designed to mimic the behaviour of traditional solid fats, allowing steam to force the dough layers apart during baking and create the flaky texture consumers expect. “Making flaky pastry is surprisingly complicated,” Professor Euston said. “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.”
The team is also prioritising environmental considerations by focusing on oils from crops that can be grown in the UK. While the production of oils such as rapeseed and sunflower can have significant environmental footprints – including land use and greenhouse gas emissions – sourcing them domestically aims to mitigate some of those concerns.
Broader applications and benefits
Although the immediate focus is on sausage rolls, the researchers believe the oleogelation process could be applied to a wide range of pastries, including croissants, Danish pastries, and sweet or savoury turnovers. Professor Euston said: “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. Reducing the saturated fat content of these ubiquitous snacks could have a very positive impact on the nation’s health and waistlines.”
The innovation could also streamline commercial baking. Traditional laminated pastry often requires repeated chilling during production to stop the fat layers from melting 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 a collaboration between Heriot-Watt University and industry partners New Food Innovation and AB Mauri, a global bakery ingredients supplier. AB Mauri operates a Global Technology Centre focused on bakery ingredient research and has also partnered with Nutris to develop fava bean-based solutions for the UK and Irish markets. The work is funded by the UK Research and Innovation Engineering and Physical Sciences Research Council (UKRI EPSRC) through its Impact Acceleration Awards, which provide flexible early-stage funding to translate scientific discoveries into practical applications.
Dr Andrew Bourne, UKRI EPSRC’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 Heriot-Watt team is also exploring whether the same oleogelation technology could reduce saturated fat in vegan cheese alternatives.
