While shortening technology evolves, the role it plays in a bakery formulation does not. Shortening dictates texture whether it’s fluffy by air incorporation or flaky by inhibiting gluten formation. And these ingredients play a vital role in shelf life and product acceptability.
While these needs have not changed, removing partially hydrogenated oils (PHOs), trans fats and reducing saturates have all made meeting those desired product characteristics more challenging. All these fats and oils have provided easy-to-work-with functionality that baked goods need from shortening: the aeration, the structure, the shelf life and the ease of use.
“We once had the technology of partial hydrogenation that allowed us to put an oil, which is a lipid that is liquid at room temperature to form a functional shortening,” said Roger Daniels, vice president, research, development, innovation and quality, Stratas Foods. “The shortening derived from use of partial hydrogenation had the means provide a means of wrapping around the protein from the flour and egg in the correct ratio without being too stiff or too loose.”
From a nutrition standpoint, however, these ingredients leave much to be desired. Mid-melters, which were commonly trans fat, enabled the desired product characteristics, but when PHOs were removed, a recplacement for mid-melters’ functionality was needed. To attain better stability, bakers now are relying on saturates, which also have an undesirable nutrition profile.
Without saturates, formulators lose the working temperature ranges that make shortening easy to process, the shelf life stability and even ease-of-use characteristics. But tailored shortening solutions can help bakers still get the plasticity and shelf life they need.
A shortening’s functionality is largely dependent on its plasticity, or its ability to be malleable at different temperatures. Partial hydrogenation resulted in shortenings that had wide temperature ranges. Without that technology, some of that flexibility was lost.
“Bakery shortenings are sensitive to temperature swings, so bakers need controlled storage spaces to ensure their shortenings don’t get brittle or too soft,” said John Satumba, PhD, global bakery technical lead and region R&D director for North America, global edible oil solutions, Cargill. “Exposure to extreme heat or cold temperatures can negatively impact their functionality in an application.”
That’s because plasticity is directly related to shortening’s core function of wrapping around proteins in the formulation’s matrix. Without plasticity, shortenings can’t get dispersed well into the batter or dough.
“For many bakers, the shortening texture and relative hardness is key to getting the proper mix. and therefore, the ideal finished product,” said Rick Cummisford, director of quality control, Columbus Vegetable Oils. “Many times, the bakeries may need to control the temperature of the shortening being used, such as refrigeration, or even mild heating of the product may be necessary.”
A shortening that is too loose or too firm will cause a different set of issues in the dough or batter throughout processing and potentially even after the finished product is made. In the case of icing, if the shortening doesn’t have temperature stability, the icing can fall right off the cake if the environment gets too warm.
“If your shortening is too loose in a pie crust, that oil will come out of the dough in the oven and fry the pie crust,” Mr. Daniels explained. “If you have a layered dough application like puff pastry or Danish and the shortening is too firm, it’s harder to spread and will tear the dough and not provide the distinct layers. There will be big gaps instead.”
[Related reading: Reduced saturated fat has shelf life implications]
Temperature-sensitive shortening means bakers may sometimes have to alter their processing parameters to keep the shortening in its semi-solid state and pay close attention to their storage temperatures. Knowing the bakery’s environment and storage capabilities is essential when choosing a shortening solution.
“Some bakeries may only have ambient storage, so then we need to know where the bakery is located,” said Kristine Thomas, senior scientist, bakery team, Corbion. “Is it in Texas or Maine, because those are two very different storage temperatures. We really need to understand the customer and their process, the environment that it’s in and what their end goal is because what’s acceptable for one customer may not be acceptable for another.”
Ms. Thomas noted that today’s shortening technology is very customizable and, therefore, can be adapted to address bakers’ needs, even in terms of environmental or processability factors. Shortening suppliers just have to know the desired processing requirements and product characteristics.
Texture, air incorporation, gluten interruption — all of these facets of a shortening are impacted by temperature, and all will have an impact on finished product. But all are also controllable to an extent by various processes.
“The texture of the shortening is key to getting the ideal finished product and making the process as efficient as possible,” Mr. Cummisford explained. “The shortening’s texture can be formulated by the vendor to meet a target level of hardness, measured by solid fat content.”
High-oleic oils can also provide stability when used in shortening blends.
“That only gets you so far, though,” Mr. Daniels said. “You also have to have a process that sets the high-oleic component in the proper configuration so that’s it’s able to survive through the supply chain.”
For Stratas Foods, its proprietary Flex technology blends the right proportion of high-oleic and standard oils and fats and then takes that blend through a controlled crystallization event before post-process tempering. This creates a shortening with a wider temperature range that can be a drop-in replacement for PHOs and improve production efficiencies and product quality.
Cargill designed its PalmAgility line of shortenings to meet the need for more robust shortening without PHOs. It can tolerate temperature swings during storage without losing workability or texture.
“This greater temperature tolerance also helps address issues that can inadvertently develop in transport or storage due to fluctuations in temperature,” Dr. Satumba said.
For example, temperature stability aids in achieving faster mix times and better incorporation of ingredients. It also has a quick set rate, which comes in handy for glazes and fillings.
Texture and temperature have an impact on air incorporation in the creaming and mixing stages as well. Melting profile and crystallization properties are key to understanding which shortening to use in a specific application.
“For icings and high-ratio cake batters, it can be challenging to distribute both the shortening and the incorporated air from the creaming stage evenly throughout the entire matrix,” said Andrea Weis, scientist II, AAK USA. “AAK scientists analyze the melting profile and crystallization behavior of new fat and oil products to determine how they will function on the production floor and in finished products. AAK develops multi-oil solutions that have been developed to meet specific process requirements.”
Additive ingredients like emulsifiers can help shortenings improve aeration in batters and icings, like in AAK’s Cisao 8116 emulsified shortening.
“Cakes made with emulsified shortening tend to have very fine and even crumb structures, yielding a light and delicate crumb,” Ms. Weis explained. “Icings made with an emulsified shortening tend to have silkier textures and enhanced stability with reduced risk of separation.”
Not all emulsifiers are alike, but they all provide some assistance to shortenings.
“There are some emulsifiers that do a great job of air entrapment just by nature of what they hold onto, whether they are fat- or water-based,” Ms. Thomas said.
Mono-diglycerides can improve gas retention, for example, and ensure bread volume even in applications where fat is reduced, according to Yanling Yin, PhD, director of RD&A, ingredient solutions, Corbion. The company’s Trancendim emulsifier can prevent stickiness and support reducing fat for many baked applications.
Melting point not only contributes to air entrapment but also eating quality. Without a proper melting profile, baked goods can taste oily or waxy. And this can impact other aspects of appearance.
“Shortenings play an important role in how a product looks and feels,” Ms. Weis said. “For example, when the consistency of fried donuts is too oily, there’s a risk that the glazes and decorations won’t properly adhere. AAK’s Cisao 8315 is an excellent donut fry shortening that has been formulated to minimize oiling out post-frying and improve the pick-up of glazes and decorations.”
This article is an excerpt from the August 2021 issue of Baking & Snack. To read the entire feature on Fats & Oils, click here.