Saturday, February 07, 2009

Better Trans-Free Baked Goods


Since the 2003 FDA mandate regarding labeling of trans fats, the food industry has made substantial strides in replacing partially hydrogenated oils. Still, work continues—particularly in some applications where trans fats provided easy solutions.

Brian Strouts, head of research and technical services, AIB International, Manhattan, KS, believes bakers and shortening manufacturers are still learning how trans-fat-free shortenings work as replacements in different appli-cations.
Success through specificity

While some shortenings work well across a broad range, “sometimes the specific choice of trans-fat-free shorten-ing can be very specific to an application,” says Strouts. “One trans-free fat may work very well in one chocolate-chip cookie formulation, and it may not work very well in another type of chocolate-chip cookie formulation, depending upon the level of fat that’s in there, the ratio of sugars and how it’s being processed.

It comes down to finding the specific shortening for a particular formulation. “We’ve done several different tests here for lots of different reasons and companies,” continues Strouts. In a specific buttercream-type icing formulation, researchers started working with “different trans-fat-free shortenings that, by their descriptions by their manufacturers, were suited for that type of icing application. We saw, as we plugged it into our standard formulation, very different performance all the way from color to smoothness to ability to hold water.” He describes the working formula as “standard as it can be. There’s not a lot of room to play around on a buttercream-type icing.”

Strouts suggests formulators trying to transition to a trans-free shortening try a variety of products from different suppliers to see which work best. Sometimes, a client has tried a single shortening and will want to give up. He suggests that manufacturers “search out different options, because it really does get to be that critical.”

Strouts believes that even manufacturers of these fats still face a learning curve. “The fat chemists have had to alter their thinking for how they construct a fat for a particular purpose,” he says. “We worked with one company in particular, and the chemist basically said he had to rethink the way he was engineering those shortenings. Just building it off of common ground like melting point and solid fat index, the way he would build fats for other ap-plications in the past, just didn’t really hold true when you start dealing with these trans-fat-free shortenings.”
From the baker’s standpoint, it “still goes back to keeping all the basic fundamental things about bakery production in mind, and keeping those controls,” Strouts says. “Things like time, temperature and sequencing of ingredi-ents remain critical.” In some cases, those parameters are even more critical with trans-fat-free shortenings.

Drop-in solution myths

Scott Erickson, marketing manager, Cargill Specialty Canola Oils, Minneapolis, sees continued work on bakery trans-fat conversion. “Unfortunately, there’s probably not one drop-in solution that works for everybody,” he says.

While customers want an off-the-shelf low-trans solution, Beatriz Bettler, regional sales manager, Cargill Dressings, Sauces and Oils, Minneapolis, says it is important to take the time to look above and beyond. “What we’ve done with our customers is embark on a journey to learn about their capabilities, process, budgets, nutritional goals, etc., to identify what product will work the best for them,” she says. “We allow ourselves the opportunity to consider all our products.”

The solution depends on the product. For example, trans is generally not an issue in bread, notes Lynn Lawrence, manager of technical services, ACH Food Companies, Memphis, TN, because it’s low-fat. Here, liquid, nonhydrogenated oils work well.

Crackers are a different story. Not only is there fat in the dough, but they typically have a spray oil, too. “Hydrogenation of fats builds stability, but hydrogenation creates trans fatty acids. The spray oil that goes onto crackers is put on at a high percentage, so fat grams are a factor in that application,” says Lawrence. He recommends high-oleic oils such as sunflower or canola, or a low-linolenic soybean oil. New oilseed breeding technologies have improved their stability.
Pie crusts require a solid shortening, where it plays a major role. “You need a certain level of saturation to provide the flakiness that is so desired in pie crust,” says Bettler. “We have had renewed interest for our animal-fat product line—specifically lard, which is still today the best pie-crust shortening. Lard is naturally low in trans and does not need further processing to perform in a variety of bakery applications. In addition, the level of saturates in lard is lower than many conventional and even low-trans shortenings.”

It’s important to consider how and when the shortening is added during mixing. To reduce trans, in tortillas, mixing the fat system with the flour first and then adding the water, or adding the ingredients all at the same time, “had a major impact in the turnout of those tortillas,” Bettler says.

Palm in hand

Most bakery applications that require a solid fat use palm shortening. Lawrence notes that solid fats provide creaming properties at room temperature, and palm oil is the simplest solution “Since palm oil is solid at room temperature,” he says, “you get good creaming properties.”
Manufacturers have had to compensate for certain palm-oil attributes. In a process with a temperature drop, palm tends to become brittle quickly, a critical problem in puff-pastry production. Puff-pastry contains a dough, and a roll-in fat. “It is cooled so that the texture can develop at a lower temperature,” says Gerald McNeill, Ph.D., R&D director, Loders Croklaan, Channahon, IL. “This is part of the traditional process. What tends to happen when you lower the temperature of palm oil products, it tends to get very hard and brittle very quickly. That’s one of the things to watch out for. I think anything that has saturated fats is going to have a hardening problem as you cool them down. In the case of palm oil, you get around that by blending different fractions.”

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.

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