Fractions are created by melting and slowly cooling the fat, producing crystals that are filtered off. The liquid fraction is then isolated. “There’s a lot of versatility in palm oil when you use fractions,” says McNeill. “There is an unlimited number of melting points and hardness. We’ve looked at the partially hydrogenated fat, physical properties, and match that using different fractions.”
Fractions can also produce shortenings with an optimum crystallization rate. “Shortening has to have a smooth, plastic texture,” McNeill says. “It’s very important that the fat, when it’s melted and cooled down in a machine called a fat crystalizer, that the crystals are a small size. The problem is that larger companies will have their own crystallizers, and they’ll buy the oil in bulk, melt it hot and put it through the crystalizers so that it comes out with just the right texture they need to blend in with the dry ingredients.” Here, palm oil crystallizes more slowly than partially hydrogenated oil. So, so manufacturers typically make equipment adjustments “like running a lower temperature or running with a slower throughput,” he continues. “We do have special palm oil fractions that crystallize quickly. If it’s difficult to adjust the equipment, if it doesn’t have the capacity, then we can put these fast-crystallizing components into the palm oil, and it crystallizes just as quickly as the partially hydrogenated oil.”
The most popular icings are aerated, and often use emulsifiers to help entrap air. Palm-based shortenings have been developed for this application. The key is to make sure the icing’s texture is soft enough for the decorating bag or for spatula use, but firm enough that it doesn’t melt or run off.
Icings made from palm-based shortenings can encounter problems, however. Some cakes have a cooling step. Palm, when cooled, will get brittle. While some manufacturers can adjust their process to reduce or bypass this cooling step, others want a palm oil with more temperature tolerance. Also, palm oil will harden over time, even if the temperature isn’t lowered, creating issues for pail icings, which can sit for several months in the distribution chain and in-store bakeries. Using fractions can eliminate these problems.
Palm oil’s darker color and unique flavor requires modification to be acceptable to cake decorators and others seeking a pure white, bland flavor. “It was difficult for us to get there with a regular palm oil,” Lawrence says. “We’ve done some things in our process and blending, and came up with a very bland, super-white-color, palm-based shortening.”
Baking trans-free requires the developer to find the optimum marriage of ingredients and functionality, while weighing costs and stability. In the end it largely comes down to trial and error―something all food developers are familiar with.
Cindy Hazen, a 20-year veteran of the food industry, is a freelance writer based in Memphis, TN. She can be reached at cindyhazen@cs.com.