Topic 2 Trans fat sources

What is trans fat?

  • In a nutshell, fatty acids (A category of fats) can have one or more or none double bonds in their molecule. Those that have at least one double bond are called unsaturated fats, often referred to as healthy fats.
  • However, among these unsaturated fats, some have a trans double bond, the trans fatty acids and are extremely unhealthy for us.

There are only two forms of importance to culinary experts; those that occur naturally in foods and those produced or added industrially.

  • In some ruminant animals, such as in cows, goats, and sheep, bacteria in their gut produce small quantities of trans fat. These later can be found in their meat (beef, lamb), especially on high-fat parts, or in products made by their milk (dairy).
  • Since trans fats are often mixed with other types of fat, the higher the fat content of a dairy product, the higher the quantity of trans fat.
  • Pork, fish, and poultry meat contain an irrelevant amount of trans fat.

The effect of these naturally occurring trans-fat is excepted to be less detrimental to our health, compared to added or industrially produced. However, nowadays most people have higher intake of trans fat from animal sources compared to industrially generated ones.

Which ingredients are naturally high in trans-fat?

  • Apart from the naturally occurring, trans fat content can increase by adding ingredients high in trans-fat or producing them through various processes from other types of fat.
  • There are three main processes that a culinary expert should be aware of, namely hydrogenation, refining of vegetable oils, and frying.
  • All these processes have one goal: to improve the taste or consistency of the final product.
Process Process description and aim Food sources high in trans fat

Hydrogenation                     

Aim is to change the nature of fat from a liquid to a solid in certain temperatures. It can improve the food item consistency, and prolong its self-life, but also inevitably generates trans fats.

All products contain partially hydrogenated vegetable oils and fats. They can be found in confectionary (cakes, cookies, crackers, bread, margarine,  breakfast cereals, candy, etc.)

Refining of vegetable oils

Aim is to remove certain impurities, the food industry. These refinements often aim to get rid of impurities that may affect the color of the fat, taste, or aroma. As this process utilizes very high temperatures, some part of fats changes to trans-fat.

These products can be confectionery (cakes, cookies, crackers, chocolates, snacks, etc.), salty snacks (chips, popcorn, corn chips, etc.)

Deep-frying

Aim is to improve the taste and consistency of a product. This process requires a lot of heat, transferred through a fat-based liquid. This high-heat liquid can transfer newly generated trans-fat directly to the food item.

Anything that is deep fried! The duration of frying and the number of reuses of an oil-based liquid used for frying can increase the content.

  • The rise of the western type of diet and the fast food industry, along with the extensive use of these processes in the food industry, has massively increased the consumption of food items high in trans-fat in the past.
  • The limitations imposed on the content of trans fat in the food industry food has significantly limited the amount of industrially produced trans fat in the past decade.
  • Currently, in most countries, the biggest source of trans fat in our diet is not the industrially produced, but rather the naturally occurring trans-fat, found in meat and dairy.