23 July 2013

Food engineering solution to obesity

Obesity
Education, exercise, food labelling, healthy-eating campaigns, taxation, regulation and restrictions on fast food advertising are just some of the options to promote healthier lifestyles. But could the real solution be to re-engineer our food to taste and look the same – but have 50 per cent less fat?

It’s a possible solution to a growing problem as consumers show few signs of changing their eating habits and obesity levels continue to rise at alarming rates. 

In the USA, around two-thirds of adults are overweight or obese, and predictions indicate nearly half will be obese by 2030. In the UK, nearly two-thirds of adults and one in three children are overweight

For several years, food engineers – also known as chemical engineers – have been looking closely at ways to reduce calories with new ingredients that mimic fats found in foods without losing the taste and texture demanded by consumers.

The solution could be a natural protein extracted from fungi such as mushrooms called hydrophobins.

In food, hydrophobins can act as a ‘foam’ and an ‘emulsifier’ to aerate and help bind ingredients together – a role normally achieved using fats and sugars. The process often determines the mouth feel and flavour of the food we eat and produce distinctive food characteristics enjoyed by consumers such as the frothy head on beer and the crumb structure in bread.

Research by chemical engineers at the University of Birmingham1, UK, found that hydrophobins have the potential to halve fat levels in some foods by replacing them with highly stable air-filled emulsions. Despite removing the fat, the foods retained the same eating experience as full fat versions and didn’t compromise texture or flavour.

The discovery means that high calorie foods heavily reliant on foams and emulsifiers – such as chocolate, ice cream, mayonnaise, salad dressings, whipped cream, mousses, milk-shakes, smoothies, crisps, marshmallows, cakes, ale, lagers, bread and even hot drinks like cappuccinos – can now be re-engineered in a way that avoids the compromises associated with many diet foods.

However, there are challenges. In their latest review2 of food foams and emulsifiers the University of Birmingham and the University of Wolverhampton indicated that developments like hydrophobins have not been widely used 'due to the conservative nature of the food industry’.

David Brown, chief executive of the Institution of Chemical Engineers (IChemE), said: “Obesity is a major issue even to the extent that some Governments have legislated and introduced ‘fat taxes’ on fast foods. In countries like the UK, the NHS estimates it spends over £5bn each year on treating obesity related diseases such as heart attacks.

“Re-engineering our food is another serious option in the battle against obesity. But it will take time. The key will be public confidence and acceptance. Many consumers are unwilling to compromise their eating and drinking experience associated with some diet products.

“Hydrophobins may be able to overcome this fundamental resistance and follow successful attempts to reduce sugar levels in foods over recent years. Artificial sweeteners and natural sugar substitutes are now widely used and accepted in foods by consumers, and, in particular, has helped to reduce sugar consumption especially in fizzy drinks.

“If the same level of trust can be achieved with hydrophobins, then food manufacturers could be persuaded to re-formulate brands worth billions of dollars and make the single biggest contribution to promoting healthier lifestyles”.

The role of chemical engineers in the food sector is explored in IChemE’s latest technical strategy, Chemical Engineering Matters. The strategy also includes actions chemical engineers are taking on other global challenges including water, energy and health.

IChemE is a registered charity in England & Wales and a charity registered in Scotland (SC 039661).