Where Did All Those 'Trans Fats' Go? [Delicious Stories]

The Secret Behind 'Zero Trans Fats' in Snacks
Thanks to Advances in Margarine Processing Technology
A Butter Substitute That Has Evolved Over a Century

Editor's NoteThe first snack is said to have been discovered in the ancient Mesopotamian civilization. Snacks have accompanied every moment of human history. From biscuits and chocolate to ice cream, we bring you delicious stories behind the snacks we have loved.

Pick up any snack at a convenience store and look at the nutrition facts label. Most products display the phrase "Trans fat 0g." Since 2007, the Ministry of Food and Drug Safety has mandated the labeling of trans fats in snacks, and today, 18 years later, domestic snacks contain only trace amounts of trans fats. Where did all those trans fats go?

Margarine and shortening are processed fats that have been filtered through a "deodorization process," which involves applying high temperatures under reduced pressure to liquid oils, followed by inducing the crystallization of trans fatty acids to harden them. For reference, the reason margarine is yellow is simply because artificial coloring has been added. Pixabay

'Enemy of the arteries' trans fats, snack content drops sharply since 2007

Trans fats were a major component in margarine and shortening, essential ingredients that add a crispy texture to snacks and bread. Since the 1990s, various studies have revealed that trans fats are harmful to blood vessels. The government mandated the labeling of trans fat content in processed foods such as snacks starting in 2007, and further promoted a "zero trans fat" campaign to reduce trans fat content in all snacks to nearly zero.

Nutrition Facts on Snack Packaging. Lim Ju-hyung skepped@

As a result, the trans fat content in domestic snacks has significantly decreased over the past 20 years. According to the Ministry of Food and Drug Safety, the average trans fat content in domestic snacks was as high as 0.7g in 2005, but now it has been reduced by 93% to an average of only 0.05g. However, the "Trans fat 0g" label on food ingredient lists does not mean absolute zero. The Ministry allows a 0g label if the trans fat content per serving (generally 20-30g) is less than 0.2g.

Why did it decrease? The secret lies in margarine processing advancements

Margarine and shortening were originally developed as processed fats to replace butter, made by solidifying oil after a "deodorization process." Deodorization involves boiling the oil at high temperatures to remove impurities, during which unsaturated fatty acids in the oil convert into trans fats. Trans fats rapidly crystallize below their boiling point, which allows margarine and shortening to maintain a solid form at room temperature. This is why margarine and shortening inevitably contain high levels of trans fats.

Before 2007, there was no mandatory trans fat labeling system in Korea, so it is difficult to know exactly how much trans fat was contained in snacks at that time. However, data from 2005 shows that the average trans fat content per serving of snacks was 0.7g, suggesting that trans fat levels were likely at dangerous levels even before then. According to the World Health Organization (WHO) and the American Heart Association (AHA), the recommended daily intake of trans fats for adults is less than 2g. Consuming just one bag of snacks (80-100g) would far exceed the daily recommended amount.

Even now, processed oils are included in most snacks and bread products. Screenshots from various internet websites.

The reason domestic confectionery companies succeeded in reducing trans fats is not because they replaced processed fats with other ingredients, but because margarine and shortening processing technologies have advanced over the past decades. After extensive research, confectionery companies discovered that rearranging the positions of fatty acids within the oil can induce crystallization similar to that caused by trans fats. Even now, most snacks contain margarine or shortening according to nutrition labels.

Esterification reactor of the German ThyssenKrupp Group. Esterified fats are used in various industries such as food, diesel fuel, and pharmaceuticals. ThyssenKrupp official website

This fatty acid rearrangement process is called "esterification exchange," and thanks to fats produced by this method, it has become possible to make hard processed fats without trans fats. Domestic companies have actively invested in esterification exchange technology.

Trans fats inevitably generated during the oil heating process are also steadily decreasing. Previously, deodorization involved heating oil above 200 degrees Celsius, but with advancements in "deodorization temperature reduction" technology, the heating temperature has been lowered. Since trans fats are formed from unsaturated fatty acids heated at high temperatures, lowering the temperature suppresses trans fat formation.

From beef tallow relief food to snack ingredient... continuous evolution

Although trans fats are now avoided, processed fats were once an innovative product that provided valuable calories and fats to the common people. In 1869, French chemist Hippolyte M?ge-Mouri?s invented the first margarine using beef fatty acids, and margarine quickly became available to the lower classes.

Margarine advertisement from the 1940s. It introduces a method of adding artificial coloring to colorless margarine to make it yellow like butter. Science History Institute

At that time, margarine had a foul odor because it did not undergo proper deodorization and was grayish with a white tint. However, for the lower classes who could not afford fresh butter and had no way to store liquid oils that easily went rancid at room temperature, it was a precious food. Especially during the early 20th century Great Depression and after World War II, margarine became a relief food for both soldiers and civilians worldwide.

By the 1950s, margarine and shortening began using inexpensive vegetable oils such as palm oil instead of animal fats, and after the invention of high-temperature deodorization and yellow edible coloring, they took on their current appetizing appearance. Today, they are essential ingredients in the mass production of countless snacks and breads in factories, and through technological advancements, they have transformed into "harmless processed foods" with suppressed trans fat content.

This content was produced with the assistance of AI translation services.