How to pick the right bakery shortening
March 1, 2013
by Laurie Gorton
Consider the problem of all-purpose shortening. In today’s post-trans-fat world of health-and-wellness formulating, partially hydrogenated shortenings don’t qualify for the nutritional tournament. Yet with their absence, the formulator not only loses the trans fats they contain but also sacrifices their wide working ranges.
Techniques for making trans-free shortenings by blending, interesterifying and emulsifying can match performance of traditional shortening for essentially any specific application, according to Don Banks, president, Edible Oil Technology, Dallas, and a consultant to the United Soybean Board.
Previously, bakers often worked with the same shortening across many applications; however, that capability can challenge trans-free styles. “As a result, some bakeries now find it best to use additional shortenings — one or two previously, now perhaps three or possibly more — to achieve optimum performance across their line of products,” Mr. Banks said.
Early attempts fell short of the net, but now bakery shortenings are getting a rematch as new oil options and different base fats rally to bakery needs. While formulators will find many new shortenings closely tied to specific applications, a number of new all-purpose and drop-in options are emerging as champions.
Bakery shortenings require both solid and liquid fats (see “What is bakery shortening?” on Page 70). Animal fats such as butter and lard provide the model. Vegetable oils are liquid in their native form. For many years, hydrogenation gave solid fat characteristics to vegetable oils, but it also backhanded some of the fatty acids from their natural cis isomer format into the trans configuration.
It’s been difficult to develop healthy, zero-trans bakery shortenings, according to Mr. Banks. “In the past, these products used highly hydrogenated or tropical fats because they needed the hard fat content,” he explained. The solution has been to combine low-saturate liquid oils with trans-free solid stocks that give the plasticizing properties required.
Dilip Nakhasi, director of innovation, Bunge Oils, Bradley, IL, described the problem, “The question was and continues to be how to compensate for the solids that trans provided. Solids are important in bakery applications for layering in croissants and texture in many other baked foods.”
Shortening manufacturers have several options for the hardstocks required. One is fully hydrogenated soybean oil. While partially hydrogenated oils carry trans fats, fully hydrogenated oils do not. Hydrogenation, when taken to completion, converts the trans fats, too, and yields 100% stearic acid, a saturated fat described as cholesterol-neutral. This material, which contains no trans fats, can be used as a hard fat for preparation of bakery shortenings.
For example, ADM takes solid fully hydrogenated soybean oil and adds liquid oil such as soybean oil or high-oleic soybean oil. It then enzymatically interesterifies the blend to yield functional shortenings suitable for a wide variety of applications, explained Michelle Peitz, technical sales representative, ADM, Decatur, IL.
Such enzymatically interesterified shortenings fit the Food and Drug Administration’s trans-free labeling rule: less than 0.5 g trans fat per serving. “They also meet the demands for North American-sourced ingredients,” said Tom Tiffany, senior technical manager, ADM.
Another choice for hardstock is palm oil and its fractions, according to Ms. Peitz and Mr. Tiffany. “By varying the level of fully hydrogenated vegetable oil or palm fractions in the blend, ADM Oils can tailor the melting and functional characteristics of the blend for the desired food application,” Mr. Tiffany explained.
At Loders Croklaan, a member of the IOI group, one of the largest producers of palm oil in Malaysia, the choice for zero-trans plastic fats for baked foods is palm oil and its many fractions. “Palm differs from oilseeds in one critical parameter: It is naturally semisolid,” said Gerald McNeill, PhD, vice-president, R&D, IOI Loders Croklaan Americas, Channahon, IL.
Commodity soybean oil provided the raw material for the partially hydrogenated shortenings of the past, but today’s products benefit from oilseed breeding programs — both conventional and biotech — that focus on specific traits. All vegetable oils consist of fatty acids but vary in proportions. Soy, canola and sunflower breeders selectively reduced the plant’s output of saturated fats in favor of forming mono- and polyunsaturated moieties. With less linolenic and more oleic content, these new liquid oils provide healthier fat profiles for bakery shortenings.
Low-linolenic soy was the first of these new oilseeds and is used today in many breads, muffins, pizza doughs and other baked foods. “Low-linolenic provides enhanced flavor stability as a replacement or alternative for all bakery applications formulated with commodity soybean oil,” Mr. Banks said.
High-oleic soy, now in final commercialization stages, has even greater potential, according to Richard Galloway, president, Galloway and Associates, LLC, Isle of Pines, SC, and a consultant to the United Soybean Board. “High-oleic soy is an excellent liquid component in bakery shortenings with its high oxidative stability, clean flavor profile and low saturates,” he said.
Using canola and sunflower bred to be high in monounsaturated fats, the Omega-9 Oils product line from Dow AgroSciences, Indianapolis, is on the market now. “Omega-9 Oils help cut saturated fat content and gives the long shelf life bakery products need because it is so stable,” said Dave Dzisiak, global commercial leader, grains and oils, Dow AgroSciences. “It can be combined with solid base stocks to get the plasticizing properties bakery products require and, thus, compares well with previous hydrogenated shortenings.”
“The advantage of using Omega-9 Oils is that we can work with a lot of different hardstocks, even going the interesterified route,” Mr. Dzisiak continued. Each use can be different. “For example, we worked with a chocolate chip application that cut the saturated fat content in half by working with a palm blend and Omega-9 Oils,” he said.
Such tailoring is the game plan most formulators and shortening producers follow these days. Fatty acid content makes the biggest difference, but the fat’s contribution to solids at lower temperature, oxidative stability and bland flavor also count. Oils from different sources vary in characteristics.
“If the shortening will be used for a product intended to have a relatively short shelf life and not subject to any significant heat stress during production, storage or distribution, then several different source fats may be candidates for the liquid component,” Mr. Dzisiak said. “However, to support products with extended shelf life and to ensure consistent flavor quality over time, a high-stability liquid oil such as Omega-9 Oils would be required.”
Jessica Blackford, research scientist, AAK, Edison, NJ, confirmed the need to take shelf life into account, saying, “The choice of oil can help the developer accomplish a formulation goal.” She cited AAK’s Cisao 81-20 as an example of an oil low in polyunsaturated fatty acids. “This palm-based general shortening provides a long shelf life with a linolenic acid profile of less than 5%,” she said.
Solid base fats provide essential functionality to bakery shortenings. “It is impossible to make a flaky pie crust or a puff pastry without solid fats,” explained Peter Y.T. Lin, PhD, principal scientist, P&G Food Ingredients, Cincinnati.
The company recently enhanced its Olean low-calorie olestra fats for use in bakery shortenings. “Olean can provide the functionality of the solid fats without the negative labeling or healthy implications,” Dr. Lin said. “It will not contribute any trans or saturated fat to bakery products because it is not digested. The triglyceride portion of an olestra shortening can then be composed of healthy liquid oils like soybean, canola and sunflower.”
From a functional standpoint, base fats that crystallize in the beta-prime form provide physical stability to shortenings, ensuring they won’t revert to the beta form that causes oils to separate from the matrix or “oil out,” as bakers sometimes call it. Base fats with a significant fraction of palmitic acid tend to support beta-prime crystallization, according to Mr. Banks. “However, there is well-established technology to produce beta-prime stable shortening using blends of base fats such as corn, olive and soy that by themselves have beta crystal tendencies,” he explained.
Mr. Nakhasi summarized, “Crystal structure is critical to baked foods, and bakers have to have alternatives to partially hydrogenated shortenings.”
The shortening puzzle has many pieces, according to Lynn Morehart, technical service manager, Cargill, Sidney, OH. “If you look at different options in base fats, you’ll find different flavors, oxidative stabilities, nutrients and solids levels as well as different costs and availabilities.” She urged formulators to balance their shortening requirements with other aspects of the final formulation, even the desire for clean-label ingredient listings. “You need to consider what is lost and what is gained,” she said.
Cargill Oils and Shortenings makes Clear Valley all-purpose shortening with high-oleic canola. “It has only 7% saturated fats versus soy or corn with 15 to 16%,” Ms. Morehart said. “It has good functionality, clean flavor and shelf life as experienced with conventional all-purpose bakery shortenings.”
Shortening suppliers generally have a large library of base oils to offer. David Hughes, senior project manager, technical services, Ventura Foods, Brea, CA, described options such as the specific oil’s nutritional profile, GMO status, sustainability angles, flavor profile and stability as well as its functionality in the baked food itself. And then there’s cost. “The oil markets have become ever more volatile, making it imperative that the technical support staff work closely with purchasing when choosing the correct oil,” he said.
Ventura Foods turned to uniquely processed emulsifiers as the foundation for its Ntrans line of low-saturated, all-purpose bakery shortenings, reported Mr. Hughes. Patented blending and crystallization methods deliver lower saturated fat levels without the need for tropical oils. “The difference between Ntrans and a typical palm oil shortening is a saturate level of 27% and 50%, respectively,” he said.
Processing, too, is part of the shortening game, and Roger Daniels, vice-president, R&D and innovation, Stratas Foods, Memphis, reported that “Stratas’ innovation team developed Flex Palm technology — the careful selection of base oils with preferred fatty acid combinations coupled with proprietary votation approaches — to deliver consistent zero-trans bakery shortenings that approach and, in many cases, match the functionality of partially hydrogenated fats for commercial bakery applications.” For example, the company’s BBS Z all-purpose shortening made with Flex Palm suits cake, pie and cookie baking as well as donut frying.
Bunge Oils developed a saturate-sparing method for preparation of its UltraBlends all-purpose shortenings. “The technology stabilizes free oils and affects the way fats are stacked,” Mr. Nakhasi said. Saturated fats were lowered by 30% compared with conventional bakery shortenings.
Stability figures into the choice of liquid oils blended with palm oil, according to Dr. McNeill. The higher the polyunsaturated content of the liquid oil, the shorter the shelf life for the finished product, and antioxidants may be required. “High-oleic canola and sunflower are the most stable of the liquid oils at present, and new high-oleic soybean oils will be available in commercial quantities in several years,” he observed.
Frying makes demands on shortenings different from those of baked foods. Snack foods need oils that are stable and provide desirable sensory attributes, Ms. Pietz explained. “Corn oil, cottonseed oil and mid-oleic sunflower oil work very well for fried snack foods,” she said.
And then there’s popcorn. Dow’s Omega-9 Oils provided a healthy shortening solution for microwave popcorn in a project with Weaver Popcorn Co., Van Buren, IN. “In microwave popcorn, the fat has to be solid so it doesn’t wick, thus compromising the packaging. And it needs a very long shelf life, unrefrigerated,” Mr. Dzisiak said. The company’s solution eliminated all trans fats and cut saturated fats by 60%, actually reducing the total amount of fat in the product. The resulting popcorn qualified to use the American Heart Association’s Heart-Check mark.
“There are marketing advantages that a reduced saturated fat and/or trans fat-free baked product can offer, whether on packaging or foodservice outlet signage,” said Patti Miller, president, Canola Council of Canada, Winnipeg, MB.
When it comes to bakery shortening performance, Mr. Nakhasi said, “The question was and continues to be how to compensate for the solids that trans used to provide.”
How a shortening handles under bakery conditions can make or break a new product. If the fat is too soft or too hard and cannot be correctly incorporated into the baked food under development, then all the bench-work developing that new item goes for naught, according to Mr. Hughes.