Transforming Baking Fat

In bakery products, one of the main requirements is a fat that has some structure and solidity. Trans fatty acids offer that, plus extended shelf life and flavor stability.

Trans fats were good to bakery products, says Bob Wainwright, director of technical service, Cargill Inc., Minneapolis. Trans fatty acid contents can be tailored to meet very specific functionalities and sensory requirements. Because trans is so well suited for bakery, it is often very challenging to identify a non-trans fat alternative that delivers equivalent finished product sensory attributes.
FDA allows products with less than 0.5 grams of trans per serving to list 0 grams per serving, providing leeway when selecting and blending fats.

Back to butter

Butter is the gold standard for flavor and functionality in many applications. Free of trans fatty acids, according to the FDA definition, and semisolid at ambient temperature, its greatest drawback is price, followed by its saturated-fatty-acid and cholesterol contents. But butter, alone or in combination with another fat, is an option for a trans fat-free claim.

Cultured butters lower moisture produces flakier pastries and fluffier cakes, says Marilyn Wilkinson, national product communications, Wisconsin Milk Marketing Board, Madison, WI. European-style has higher butterfat content than standard butter, producing a more flavorful butter that is beneficial for baking and can be used at higher temperatures, without burning, to produce a lighter, flakier pastry.
Bakers solidify formulas

Butters semisolid nature at ambient temperature suits it to baked products. Semisolid shortening products, or plastic fats, when beaten, can hold air bubbles in their malleable masses, act as a spacer, as in a pie crust, and facilitate leavening, as in puff pastry. Plastic fats contribute to baked goods structure by coating and shortening gluten strands. The fat retards gluten development, thus contributing to tenderization.

Vegetable-oil shortenings tend to stay more solid at room temperature and often cream better than butter because they contain mono- and diglyceride emulsifiers. Shortening is thus better-distributed than butter and more efficient at coating flour, minimizing gluten development.

Liquid fats do not contribute the same functionality. Oil coats flour particles, producing smooth dough, easy mixing, reduced mixing times and some mixing tolerance. It also prevents some gluten development, but not as effectively as plastic fats. Oil does not aerate when creamed with sugar, so it lacks air-holding properties.
In general, oils rich in polyunsaturates are poor replacements for hydrogenated fats in baking, as they are liquid at use temperatures and prone to oxidation. However, new oils, such as low-linolenic soybean, high- and mid-oleic sunflower, and high-oleic canola, have �varying degrees of stability against oxidation, says Wainwright. Not all liquids are so high in polys that they are high-risk ingredients, oxidatively speaking.

Completely hydrogenating oil saturates all double bonds to single bonds, so there can be no trans fatty acids. However, consumers have become leery of the term hydrogenated.

Oil options

Lard and beef tallow were also bakers favorites in certain applications, due to their structure and saturates. Partially hydrogenated vegetable shortenings became de rigueur replacements in the United States.

However, European bakers who opt not to use animal fats almost always choose palm or coconut oil. While palm contains no trans fatty acids, around half of the fatty acids are saturated, as compared to conventional soy (15%), sunflower (12%) or canola (7%). Because palm and coconut have enough solids, they generally do not require hydrogenation for stability or for functions such as creaming and crystal structure. Most bakers conducting reformulations turn to tropical oils, but the saturate content keeps them from being the ideal solution. Advanced breeding technologies produce canola, soybean and sunflower seeds with low-linolenic fatty-acid contents and/or high oleic levels. Linolenic, an omega-3, is highly unsaturated and very unstable, whereas oleic, a monounsaturated omega-9, is much more stable.
Indianapolis-based Dow Agro- Sciences LLC developed canola and sunflower with a unique combination of high-oleic (less than 70%) and low-linolenic (less than 3%) fatty acids. Omega-9 oils can deliver a zero trans fat and significantly reduced saturated-fat content, says Roger Daniels, director�new business development, Bunge North America, Bradley, IL.

Reduced-trans shortenings can be blended with other fats in such a way to keep trans at zero and saturates low, thanks to the 0.5-gram rounding-down rule. Our patented RighT technology hydrogenates oil using a specific catalyst under heat and pressure, says Daniels. This reduces trans by 80% and keeps saturates low.

Solidifying sans trans

One process for solidifying vegetable oils is interesterification, which shifts fatty acids within the oil molecules, improving melting properties and functionality.

Interesterification provides a means of conferring a desired melting profile to a blend of an oil and a fat, without the use of partial hydrogenation says Daniels.
Interesterification enables a fully saturated fat to interchange with a nonhydrogenated unsaturated oil to give a mix of triglycerides that have a final melting profile tailored to specific applications. It is also possible to interesterify nonhydrogenated fats together to give the desired melting profile.

Unilever R&D, Vlaardingen, London, and Wageningen University, the Netherlands, have identified a new way of structuring oils without adding saturated or trans fatty acids. They start with sunflower oil and add lecithin and sorbitan tristearate (STS), both commonly used as emulsifiers and crystal-habit modifiers.
Mimma Pernetti, researcher, Unilever, says: The thermo-reversibility and shear-sensitivity of the resulting gel may allow several bakery applications.

Making the switch

Ultimately, it depends on which line on the Nutrition Facts needs to be low or zero: saturated or trans fat. Theres a very broad spectrum of options available, Wainwright says. And the options are expanding.

In 2001, at the request of a customer, we moved from baking their oyster crackers with partially hydrogenated soybean oil to trans-fat-free palm oil, says Keith Dunn, vice president and general manager, Westminster Cracker Company, Inc., Rutland, VT. The reformulation was perfected in about a month, with no changes to other ingredients, baking times or equipment. In fact, the fat per serving actually went down. At the time, the economics would not allow us to mainstream the new formula into general distribution and remain price competitive; however, in 2004, the availability and price of trans-fat-free oils allowed us to convert all Westminster crackers to trans-fat-free status. The company is currently using high-oleic canola oil in all of its crackers.

While some changes come easier than others, Wainwright concludes: There is no magic bullet. Rather, bakers should be prepared to reformulate in terms of order of ingredient addition, mix protocols, processing temperatures and other variables. Fats and oils are often major ingredients in many bakery products, and any change to such a key ingredient of necessity demands changes elsewhere to recover finished-product attributes.