People like to eat pastries. They are a flavorful combination of flour, sugar, and fats. In generations past, pastries were prepared with either butter or lard. But these fats are at the same time too expensive and unhealthy. They are high in saturated fat.
Manufacturers turned to vegetable oils instead. The problem was that these oils did not produce the same tasty pastries. You see, butter and lard are solid fats at room temperature, whereas vegetable oils are liquid. The resulting pastry simply did not “stand up” or provide the right mouthfeel.
Science came to the rescue with a technique called hydrogenation. Liquid oils were bombarded with hydrogen atoms until they started to solidify. Partial hydrogenation provided the best result for food production. There was one problem. The new fat compound, called trans-fat, was found to be unhealthier than the fats from butter or lard. However, these partially hydrogenated fats were cheap to manufacture, so companies used them anyway for many decades.
It took a while, but trans-fats are starting to disappear from our food supply, due to regulation, labeling requirements and consumer demand. The need for fats that are solid at room temperature has not diminished though.
There are currently 2 alternatives, and neither is good news:
1. Fractionated Oils. These oils are usually produced from palm oil or palm kernel oil. These oils are relatively high in saturated fat, but the processing makes them even higher in saturated fat. This is how it works: the original oil is heated, and then cooled. When cooling, the oil separates into fractions, some with higher saturated fat content than others. The fractions with the highest levels of saturated fat are pooled together and are used for baking applications. Remember – the higher the saturated fat level, the more solid the fat.
2. Interesterified Oils. This is a bit more complicated. The process of inter-ester-ification causes a redistribution of the fatty acids inside a fat molecule. Fatty acids are the building blocks of all fats. The rearrangement changes the melting point of the fat. There have not been sufficient studies on the health effects of intereseterified oils.
3. Fully Hydrogenated Oils. See our post on full hydrogenation here.
Our recommendation when you see these oils in product ingredient lists – choose another product.