SNACKS JUST AS GOOD BUT HEALTHIER THANKS TO SCIENCE
How is it possible that trans-free sweets in our diet pose a lower risk of diabetes and atherosclerosis? Prof. Grażyna Budryn from the Institute of Food Technology and Analysis - Faculty of Biotechnology and Food Sciences, TUL, writes about this subject.
Snacks, just as good, but healthier thanks to science. Trans-free sweets mean lower risk of diabetes and atherosclerosis! A technological challenge that paying off.
Most snacks contain fats in the recipe. Chemically hardened oils produce trans fats, which give very good characteristics to snacks such as biscuits, bars, including those with creams and fillings. Technologically excellent, they make desserts fluffy and soft, but health-wise they increase the risk of atherosclerosis and diabetes.
Trans fats are already being censored in many countries fighting obesity. As a result, non-trans fats, hardened through enzymes and freezing, are emerging. Snack manufacturers must now change technology to use zero trans fats. Making the change requires interdisciplinary knowledge, starting with knowledge of machinery and ending with the impact of diet on health.
Researchers from the Faculty of Biotechnology and Food Sciences at Lodz University of Technology have taken on the challenge of developing technology to make bread and biscuits using zero trans fats. Thanks to a three-year project, they tested new zero trans fats technologically and obtained promising know-how and patents. The technology has now been taken up by snack manufacturers.
The new healthier desserts are a step towards a healthier society!
How are trans-fatty acids formed?
Trans-fatty acids are produced during the hydrogenation of fats, mainly vegetable oils. This process produces fats with a higher melting point and lower levels of unsaturated acids. Hydrogenated fats obtained in this way have wider application possibilities, due to altered rheological properties and higher durability, due to a reduction in the amount of unsaturated fatty acids. However, trans fatty acids are not indifferent to health. Not only do they raise the level of "bad" cholesterol (LDL), but they also lower the level of "good" (HDL). In contrast, saturated acids, which are also considered to raise 'bad' cholesterol, do not contribute to reducing the 'good' cholesterol fraction. A comparison of the Swedish and American diets in studies conducted in the 1980s established that the consumption of saturated fatty acids is not as dangerous to health as the consumption of trans-configured acids. Trans fats, when built into cell membranes, significantly reduce their elasticity.
How are trans-free fats made?
Trans fats are obtained by enzymatic interestrification, during which fatty acids change their place of attachment to glycerol. Interestrification changes the structure and composition of the triacylglycerols, but does not change the natural structure of the fatty acids they contain. This leads to an increase in the proportion of solid phase (SFC) and an improvement in fat plasticity. Furthermore, this process can beneficially modify the melting curve.
Another method for obtaining trans-free fats is fractionation. This method involves separating fats, mainly vegetable oils, into fractions differing in melting point. This can be achieved by cooling and filtration, whereby the fraction with a high melting point crystallises and is separated out. The use of controlled fat crystallisation makes it possible to obtain two fractions: a solid phase (stearin) and a liquid phase (olein). Stearin, which is a solid natural vegetable fat, is used in the production of bread and snacks. The use of zero trans fats in food instead of trans fats requires a lot of research due to the different melting curve and the change in rheological characteristics. Without developing new technological parameters, delamination, fat leakage, crumbling, rancidity and other serious product defects would occur. Researchers at Lodz University of Technology have successfully taken up the challenge of implementing zero trans fats into many types of food.
The work of scientists from the Faculty of Biotechnology and Food Sciences, TUL, on the levels of trans and zero trans fats in food: