The World Health Organization is strongly advising that appropriate actions need to be taken due to obesity levels worldwide having nearly doubled since 1980. Many factors related to our lifestyle are responsible for this situation. The most important is our diet, more precisely our calorie intake. The number of calories which should be consumed daily is individually tailored to every single person’s lifestyle and varies depending on age, sex, job type and physical activity. However, energy balance works the same way for everyone. To maintain healthy weight the number of calories we eat during the day should be equal to the number of calories we burn. When we eat more than we burn the calorie surplus is turned into fat and weight gain occurs. Our bodies utilise available internal fat reserves when additional energy is required to keep us going when food is not provided externally. Using our stored energy reserves leads to weight loss.
Nowadays people are interested in maintaining a healthy lifestyle and seeking healthy low calorie food products to support their diet. In order to meet the consumer’s expectations food manufacturers are continuously improving existing food products by making them less calorie- dense. Consumers’ decisions regarding healthier food products are based on several elements such as: nutritional value, calorie content, no artificial additives. Nevertheless flavour, appearance, and texture are equally important.
Fats as a food component impacts on all of the factors mentioned above and that is why reduction of content without compromising on any of them is a very challenging task. Ideal fat mimetics should cover all the fat sensory functions and additionally provide fewer calories which in practice is very hard to achieve. Unfortunately at the moment low-fat products are perceived as watery and lacking taste. Chemical engineers are working to change this and are interested in reformulation of food products with newly designed food microstructure. The aim is to mimic fat as closely as possible and help to reduce unhealthy components, whilst maintaining the same oral response as the original product. Recently discovered materials which show potential as fat replacers in semi-solid food products, such as margarine and mayonnaise, are called fluid gel. Their structure is made of gelled particles dispersed in non-gelled liquid. In contrast to an ordinary gel, ‘sheared’ gel behaves very similarly to emulsions used in food formulations. Scientists are now trying to mix various gelling materials to find a perfect fat mimetic. Investigated mixtures are based on natural components derived from seaweed which is calorie free. This means that instead of using fat which provides nine calories per gram, we can use almost zero calorie mixed fluid gels and the difference between full fat and reduced fat products would be impossible to distinguish between by our senses.
The research undertaken to date, showed promising results. There is a significant potential to improve the existing situation and produce consumer friendly, low calorie food products with an appealing look which are enjoyable to eat. This brings a new perspective on healthy eating, especially for people trying to maintain an ideal body weight and struggling because of the poor quality dietetic products currently available on the market. Chemical engineering approaches to reformulate food products using new materials such as mixed fluid gels is a powerful tool which can be used in the ongoing fight against rising obesity levels worldwide.
About the author:
Izabela Gładkowska-Balewicz is a final year Doctoral Researcher at the University of Birmingham within the School of Chemical Engineering as a part of Professor Ian Norton’s Microstructure Research Group. Her research interest involves gelling agent mixtures, network formation and properties characterization (flow patterns, phase transitions, design of materials and processes). The aim of her research is to understand and develop methods which will enable to control mechanisms governing mixed biopolymers microstructure formation. Possible application for mixed biopolymer sheared gels is a fat replacement in reformulated semi-solid food products.