KANSAS CITY — Give credit — or blame, if you like — to scientists from the Harvard School of Public Health for all the work bakers and their suppliers must now do to replace shortenings containing partially hydrogenated oils (phos).
Revocation of the Generally Recognized as Safe (GRAS) status of phos by the Food and Drug Administration (F.D.A.) in June 2015 is largely due to that work. In the 1990s, these researchers initially sounded the alarm about trans fatty acids and their degenerative impact on the cardiovascular system.
Revoked, not banned
Seeking to better stabilize vegetable oils, which were widely available, oil chemists experimented with hydrogenation to convert the carbon double bonds present in unsaturated fatty acids. They succeeded wildly and set the stage for vegetable oils to replace animal fats.
This change to phos was seen first as beneficial and healthy, but a closer look at the nutritional consequences proved everyone wrong. Hydrogenation flips the isomeric form of some fatty acids from their natural cis configuration to trans. In the past, humans consumed trans fats only when eating animal fats. Today, phos are the leading source of trans fatty acids in the human diet and in bakery shortenings.
Removal of their GRAS status does not ban outright the use of phos in foods. Instead, by 2018, food manufacturers who want to continue to formulate with these fats must now submit a food additive petition to the F.D.A. detailing their safe use.
The F.D.A. once estimated that almost all crackers, about 95% of prepared cookies and 80% of frozen breakfast products contain trans fat. The addition of this one line of information on the Nutrition Facts Panel fueled a major shift in bakery shortenings intended for use by retail and wholesale bakers.
In general, baked goods are one of the toughest applications to reformulate because the fat performs structuring, flavoring and texturizing roles. Breads and rolls made the easiest conversion to liquid oils, and some cakes were readily reformulated with oils. With cakes, however, there are challenges for high-ratio formulas, where sugar and shortening must be creamed to give the finished products the right texture. Pie crusts are quite difficult to make without the solid fats contributed by shortenings. The roll-in fats and margarines for croissants and Danish are also hard to replace.
Bakery shortenings typically consist of low-melting-point liquid oils and higher-melting-point solid fats. They are compound products often containing many types of fats and oils, with the solid fats forming a matrix around the liquid oils. This yields a semi-solid fat that is soft, smooth and spreadable with optimum lubricity and desirable crystalline structure.
“Bakery shortenings must have appropriate plasticity to be creamed into a dough or batter but also lend specific characteristics while being deposited, baked and packaged,” said Lynne Morehart, senior principal scientist, oils and shortenings, Cargill. “If used in cakes, frostings or yeast-raised products, they will typically contain emulsifiers, which will aid in aeration and moisture retention.”
Bakery shortenings require some level of solids for performance. Their unique composition contributes many desirable functions to baked goods, such as aeration, crumb softness and structure, dough lubricity, emulsification, extended shelf life and overall improved palatability.
Long ago, many of these functions were achieved simply through the use of solid fats sourced from animals, such as butter (milk fat), lard (pork fat) and tallow (beef fat). However, when the health community raised concerns about saturated animal fats, suppliers responded with vegetable-based choices.
“The introduction of hydrogenation allowed use of domestic vegetable oils, such as cottonseed, corn and soybean, at low cost in bakery shortenings,” said Bob Johnson, director of oils, R&D, Bunge North America. “When an oil is hydrogenated, its fatty acids are converted from polyunsaturates to monounsaturates to saturates. Directionally, this can be seen as a hardening of the oil or an increase in its solids and melt point.”
This is where the distinction between partially hydrogenated and fully hydrogenated must be made. The difference enabled much innovation in the category.
“When an oil is partially hydrogenated, some of the monounsaturated fatty acids exist as the trans isomer. This is the concern with phos,” Mr. Johnson said. “But when that oil is fully hydrogenated, those monounsaturates are converted to saturates, which do not have any trans present.” These saturates provide solids that can be used in structuring bakery shortenings.
Going fully hydrogenated
Every oil chemist knows that fully hydrogenated oils (fhos) contain virtually no trans fats, a fact not well understood by consumers but known to formulators.
“Fhos are made by bubbling hydrogen gas through liquid oils at high temperature in the presence of catalysts, such as nickel and sulfur,” said Gerald McNeil, vice-president of R&D for IOI Loders Croklaan Americas. “At the end of this reaction, almost all the double bonds in the oil have been converted to single bonds. In addition, if any trans fat was in the original oil, that trans fat will be almost completely eliminated and converted to saturated fat.”
According to the F.D.A., some non-hydrogenated refined oils may contain trans fatty acids as a result of high-temperature processing normal to the refining of raw oils. These exist at levels typically below 2%. Low levels (below 2%) may also be found in fhos due to incomplete hydrogenation. Small amounts, typically around 3%, may be found naturally in the fat component of dairy and meat products from ruminant animals. All of these remain GRAS and part of the solution to eliminate phos from product formulations.
Enter interesterification, stage right. “Fhos are composed of more than 95% saturated fat and, as a result, are a hard, waxy fat that is difficult to disperse in oil,” Mr. McNeil said. “To overcome this drawback, fhos can be interesterified with the liquid oil instead.”
Richard Galloway, consultant and oils expert for Qualisoy, said, “With interesterification, you can produce a shortening with virtually the same functional properties previously only available through partial hydrogenation.
“Interesterification is a processing technique that achieves solid and semi-solid shortenings,” he continued. “These shortenings are characterized by very flexible melt points and melt curves with extraordinary oxidative stability.”
A new look at saturates
Depending on the application, animal fats have once again become a go-to solid fat for bakers, as have highly saturated vegetable fats, such as those derived from coconut and palm.
“Market trends demonstrate that consumers are seeking natural sources of saturated fats, such as coconut oil, grass-fed butter and palm-based oils,” said Monica Zelaya-Brown, customer innovation manager for AAK USA Inc. “Butter remains the gold standard among bakers in terms of its processing capability, as well as its ability to deliver on texture, quality and flavor. Lard is used much like butter. Palm-based solutions are process-tolerant, highly versatile in their functionality due to a variety of components that can be tailored from palm and palm kernel oil, and are able to deliver appropriate melting, structuring and textural behavior.”
Palm oil, always popular in Europe, is getting more attention from American bakery formulators.
“Palm oil by itself is naturally a shortening, similar to butter, and can be used in a wide range of baked goods,” Mr. McNeil said. “We provide customized solutions for the baked goods industry and currently have more than 300 shortenings based on palm oil and domestic oil blends.
“The versatility of palm oil is due to a physical pressing process that can generate harder or softer versions of the original palm oil,” Mr. McNeil said.
Because of this versatility, suppliers can create customized solutions to meet the industry’s needs, such as reducing saturated fatty acid content. Even though saturated fat is not as “heart unhealthy” as once thought, dietary recommendations continue to emphasize keeping intake at bay.
Further, not all saturated fatty acids are created equal.
“Interesterified soybean oil has elevated levels of stearic saturated fat but low levels of palmitic saturated fat,” Mr. Galloway said. “Numerous studies have shown that stearic acid does not raise ‘bad’ (low-density lipoprotein) cholesterol levels because the body converts it quickly to monounsaturated fat (oleic acid), which is the fatty acid commonly found in olive oil.”
Bakers are taking a closer look at the levels of saturated fats in their shortenings. For example, the technical staff at IOI Loders Croklaan Americas found that customers liked the performance of its oils but complained about high saturated fatty acid content, which was a minimum of 50%.
“We screened about 50 reduced-saturated fat prototype formulas and evaluated their performance in multiple applications,” Mr. McNeil said. “Of these, we found four candidates that were all less than 40% saturated fat. They all performed the same or better than higher saturated fat counterparts.”
The nutrition community continues to debate the pros and cons of the different types of saturates in the diet. There is not a single simple answer to the question of whether saturates are desirable or not, according to Mr. Johnson. Regardless, there are many branded product market leaders with goals of reducing saturated fats in their products, and ingredient suppliers are actively developing label-friendly options. Many of these companies have mandates to simplify labels with easy-to-understand ingredients.
“Lard, tallow, butter and palm can simplify and clean up labels,” Mr. Johnson said. “Lard and tallow are excellent shortenings but have the challenge of not being kosher and cannot be used by many large bakeries for that reason. Palm performs well and meets many clean-label needs but has struggled due to perceptions about its sustainability. Butter usage has continued to rise in the segment of cleaner-label, higher-end baked goods.”
Broad menu of choices
With the intense scrutiny given recently to trans fats and phos, ingredient suppliers have expanded their product offerings considerably. And some are exploring new sources.
Bunge offers a broad range of non-pho solutions. “There’s an ingredient for every bakery application,” Mr. Johnson said. “For our cracker customers, we offer high-stability soy and canola oils. We have also developed a process that allows us to enzymatically structure bakery shortening using only domestically grown soybeans.”
The company formed a joint venture with Solazyme to launch micro-algae-based fats and oils last October. The line includes high-stability algae oils and an algae butter-type structuring fat. The latter has a composition and functionality for superior performance in baked goods, including applications such as icing and frosting, as well as croissants, which require hard fats that are solid at room temperature, yet still have melting properties.
“In all, we have non-pho fats that range from 17% to 65% saturated fatty acids,” Mr. Johnson said.
Cargill has multiple products available as pho-free shortenings.
“There are palm-based shortenings, interesterified shortenings, palm/liquid oil blends and liquid oil/fho blends,” Ms. Morehart said. “We work with our customers to understand their applications, as well as labeling and nutritional parameters to help them determine the shortening to meet their needs. As we dig deep to understand what our customers need to achieve, they often discover attributes along the way that take them in a different direction than their initial thought.”
At AAK, blending of various oil stocks increased the company’s range.
“Our pho-free shortenings are produced from different components,” Ms. Zelaya-Brown said. “We can use fractions or interesterified blends of palm and palm kernel oils, oleins and stearins; soft oils such as canola or high oleic sunflower/canola oils; and soybean oil, with the option to interesterify it for desired functionality.”
Suppliers who blend varied fats pride themselves on delivering ingredients with multiple functions. Ms. Zelaya-Brown described a recent project: “A customer wanted to penetrate a very competitive market segment and did not have sufficient R&D resources to dedicate to the product development of a high-quality, bake-stable cookie filling,” she said. “AAK had the capability to support this project by developing a two-pronged approach for the cookie dough itself, as well as the filling. The end result was a cookie with a better texture for an extended period of time.”
The F.D.A.’s revocation of GRAS status for phos is something bakery shortening suppliers have anticipated for nearly a decade, if not longer. The fats and oils industry has responded effectively to the evolving needs of the baking community in the post-pho era.
“Solutions are available for all applications,” Mr. Johnson concluded. “The challenge for many is in balancing the cost of the solutions with the specific attributes that are needed for their products.”