Research published in the European Journal of Lipid Science and Technology shows that the proportion of foods on the German market containing trans-fatty acids (TFA) is declining – especially within the former high risk food groups such as French fries, margarines and shortenings.
However, the authors led by Katrin Kuhnt from Friedrich Schiller University, Germany, noted that there is a considerable variation of TFA content, “with mainly bakery products and confectioneries having extremely high values, predominantly associated with high total fat and SFA proportion.”
Kuhnt and her colleagues noted that a number of studies provide evidence that a high TFA intake, particularly of industrial origin, adversely affects human health – adding that the TFA content of foods could be reduced by the introduction of mandatory regulations and modifications in the hydrogenation process of oils.
The two major dietary sources for trans-fatty acids (TFA) include production via industrial hydrogenation of vegetable oils (partially hydrogenated vegetable oils) and through bacterial hydrogenation in the rumen.
Compared to unhydrogenated oils, partially hydrogenated vegetable oils containing industrial TFAs are semi-solid, have a higher oxidative stability, and a longer shelf life, and are commonly used in processed food products including margarines, deep-fried foods, bakery and instant products as well as in confectioneries.
The authors noted that a number of experimental studies “demonstrate a positive correlation between the consumption of industrial TFA and the risk of coronary heart disease, due in particular to the adverse influence on the lipoprotein profile in serum.”
The researchers determined the TFA distribution of contemporary foods in 339 German foods from six categories: semi-solid fats, deep-fried potato products, bakery products, confectioneries, instant products and butter.
The study results showed a high variation of TFA content between and within the categories containing between 0 and 40.5% TFA.
“In the present study, 96% of the deep-fried potato products, 90% of the confectioneries, 90% of the instant products and 82% of the semi-solid fats contained less than 2% TFA,” explained Kuhnt and her team.
They reported that the mean TFA value in 116 confectioneries was below 2%, though they noted that values of up to 41% were found in certain products.
Bakery products had the highest average TFA content, at 4.5%, with 40% of the 60 products tested showing TFA contents higher than 2%.
Though trans-fats are not, yet, subject to regulation in most countries, many industry players have begun to reformulate away from them in recent years.
Whilst the situation in Germany seems to be mixed, Barbara Gallani, director of food safety & science at the Food and Drink Federation told FoodNavigator that the artificial trans fats have been virtually eliminated from processed foods in the UK, due to “a significant focus on reformulation by UK food manufacturers.”
“This move away from artificial trans fats has been confirmed by data published by the Department of Health last week which analysed a variety of processed foods for trans fatty acids,” said Gallani.
“The latest National Diet and Nutrition Survey shows that reductions already made have resulted in the consumption of trans fats falling from 2.1% of total energy in 1985 to an estimated 0.8% of total energy in 2010, which is well below the maximum UK and WHO recommendations. The UK government has concluded that TFAs at current intake levels do not pose health risks to UK consumers, an opinion with which we concur,” she added.
Source: European Journal of Lipid Science and Technology
Published online ahead of print, doi: 10.1002/ejlt.201100037
“Trans fatty acid isomers and the trans-9/trans-11 index in fat containing foods”
Authors: K. Kuhnt, M. Baehr, C. Rohrer, G. Jahreis