Fats, oils and lipids — these terms are often used synonymously and refer to a class of food components and ingredients that play an important role in baked foods. Without them, pound cake looks dull, croissants don’t pull apart, biscuits are bland and muffins dry out.
The good news is that today’s nutrition-savvy consumers no longer fear fat. Concerns are directed to specific components of lipids: the fatty acids. With simple lipids, one (mono), two (di) or three (tri) fatty acids are attached to a glycerol backbone by esterification. These fatty acids (number, placement and type) define the lipid’s characteristics.
In the world of baking fats, most lipids contain three fatty acids. If the majority of fatty acids are saturated (no double bonds) with hydrogen links to the backbone, then the lipid is solid. As the degree of unsaturation measured by the presence of double bonds increases, the lipid becomes more liquid.
Bakers tend to prefer more solid fats because they have greater oxidative stability and provide structural properties necessary to cakes, cookies and other sweet goods. Subsequently, bakers have historically opted for highly saturated lipids or unsaturated lipids that have been partially hydrogenated. The latter is a process that reconfigures an unsaturated fatty acid to be more solid but, as a result, produces trans fatty acids — the taboo word in today’s food formulating world.
Not so long ago, partially hydrogenated fats were preferred over saturated fats because saturates have a reputation as being artery cloggers. In a twist of fate, saturated fatty acids now have a better image than trans fatty acids.
‘BOND, DOUBLE BOND.’ As mentioned, saturated fatty acids have no double bonds, while unsaturated fatty acids have one or more. If there’s one double bond, they are referred to as monounsaturated; if there are two or more, they are polyunsaturated fatty acids (PUFAs). Because monounsaturated fatty acids are only one double bond away from being a saturated fatty acid, they are considered more stable than PUFAs. Further, within the polyunsaturates, the highly desirable omega-3 alpha-linolenic acid (ALA), an 18-carbon chain with three double bonds, is one of the most prone to oxidation. Another prevalent PUFA is linoleic acid (LA), an omega-6 made of 18 carbons and two double bonds. With one less double bond than ALA, LA is more stable.
To formulate baked foods with an appealing fatty acid profile, bakers can take a 2-step approach. First, choose an oil that is high in monounsaturated fatty acids, usually oleic acid (OA), which contains 18 carbons and has a single double bond at the ninth carbon from the terminal end of the chain. This configuration has some lipid chemists referring to monounsaturates as omega-9s.
Plant breeders have been using conventional crossbreeding technologies to develop an array of vegetable oils with higher OA content and lower ALA content than their classic counterpart. For example, in December 2007, Asoyia LLC, Iowa City, IA, rolled out Mid Oleic Ultra Low Lin Soybean Oil.
"Both the canola and sunflower industries have bred seeds with identity traits such as mid-OA contents. This is a first for the soybean industry, which is one of the most readily available crops in the United States," said Greg Keeley, c.e.o., Asoyia. "We started with Asoyia’s first generation Ultra Low Lin Soybean Oil, which contains no trans fats, is low in saturates (14%) and contains less than 1% ALA. Advanced breeding enabled our farmers to increase the OA content while decreasing the less stable LA content. The result is oil that substitutes for other oils in recipes but is more stable, allowing greater heat tolerance in ovens and ultimately a longer shelf life product."
Breeding plants for identity traits has been going on for some time. In 1995, members of the National Sunflower Association (NSA) began the process to change the fatty acid structure of sunflower oil. The new oil was to have a pleasing taste, be stable without partial hydrogenation and be low in saturated fat levels. The NSA initiative was supported by the US Department of Agriculture plant breeders, the industry and sunflower growers, and the result is NuSun sunflower oil.
NuSun oil is a mid-OA sunflower oil. It is lower in saturated fat (less than 10%) than classic sunflower oil and has higher OA levels (55% to 75%) with the remainder being LA (15% to 35%). It is virtually free of ALA. Although this discussion is focused on baked foods, it is worth noting that research indicates that frying oils must have some LA for flavor development. NuSun, at an average of 25% LA, has been identified as possessing the optimum amount of LA to develop a desirable fried food flavor in most applications.
Interestingly, classic corn oil and cottonseed oil are both virtually free of ALA, as well as trans fatty acids (on a per-serving basis). The problem with these two oils is that they are high in saturates (13% and 27%, respectively) and not very high in OA. They are predominantly LA, which makes them unstable. However, antioxidant addition can assist in this area.
Like the aforementioned oils with identity traits, there are two types of canola oils: commodity or classic, which is primarily a retail product, and high-OA, which is for industrial and food service operations. Both oils have the same low level of saturated fat and no trans fatty acids; the only difference, as the name suggests, is that the high-OA canola oil contains more OA and fewer PUFAs. This fat profile makes high-OA canola oil more stable. In many applications, including cookies and crackers, high-OA canola oil can substitute for partially hydrogenated oils. High-OA canola oil is marketed by a number of suppliers.
There are other vegetable oils available to bakers, but they are either too expensive (olive), not readily available (safflower) or unstable (flax). For example, flax seed oil is naturally very high in ALA. In fact, when it shows up in applications, it is often for the sole sake of raising omega-3 content. High ALA means it is very unstable and should not be used in baked applications.
OMEGA-3 ADDITION. This brings us to part two. Lipids high in ALA are not recommended for baked food applications; therefore, to increase the omega-3 content, it is necessary to fortify with an omega-3 ingredient.
There are basically three omega-3s available for ingredient use: ALA, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Plant-derived ALA is an essential fatty acid and can be converted in the human body to DHA and EPA; however, the efficiency of this conversion process from varies by consumer, diet and other factors.
A variety of omega-3 ingredients are available to bakers, each unique in its own way. For example, a new ingredient — Pizzey’s MeadowPure O3 Ultra — provides all three omega-3s in a free-flowing powder.
"MeadowPure O3 Ultra provides the essential fatty acid found in flaxseed along with those found in fish oil," said Mary Ekman, business development manager, Pizzey’s Nutritionals, Gurnee, IL. "The antioxidants in flaxseed do a great job of preventing the omega-3s from oxidizing.
"With MeadowPure O3 Ultra the benefits are twofold for bakers," Ms. Ekman said. "Bakers get omega-3s, and they can replace the fat ingredient. For example, in a bread-type product, one cup of shortening would be replaced with three cups of MeadowPure O3 Ultra. Water addition should increase by 75% of the weight of the flaxseed because the flaxseed absorbs moisture. In other baked foods, MeadowPure O3 Ultra can replace some of the fat. It varies by application."
Other omega-3 ingredients focus solely on DHA and EPA, the two omega-3s that qualify for a health claim. "MEG-3 Omega-3 EPA/DHA powder is a highly concentrated omega-3 fortifying ingredient made using the patented microencapsulation technology called Powder-loc," said Lori Covert, vice-president, marketing and communications, Ocean Nutrition Canada Ltd., Dartmouth, NS.
MEG-3 is derived from fish oil. "This crude oil is very pure, but we further refine it to meet the highest purity standards," Ms. Covert said. "The Powder-loc technology provides double-shell protection, which means that each oil droplet not only has its own protective shell, but all the single shells are then grouped together and protected in a second shell. This process locks in the health benefits of omega-3 and locks even the slightest hint of fishiness out of the food. The end ingredient is a free-flowing, dry powder with a consistency similar to flour."
Good Foods Enterprises, Brampton, ON, includes MEG-3 in its new Mr. Cookie products, which are part of the Ontario school lunch program. Mr. Cookie is a 4-in., individually wrapped cookie that comes in three flavors: oatmeal, chocolate chip and double chocolate. Each nutfree, trans-fat-free cookie has 25 mg of MEG-3.
"We have been servicing schools for more than 10 years, and we thought adding the MEG-3 ingredient to our cookies was a huge step forward in helping kids receive their daily intake of EPA and DHA," said Aman Rajan, president of Good Foods Enterprises. "Adding the MEG-3 EPA/DHA ingredient to our product also has increased sales by 75%, which has exceeded our expectations."
Another option for bakers is OmegaPure refined menhaden oil from Omega Protein, Inc., Houston, TX. "Wild caught menhaden fish are harvested and processed to obtain crude menhaden oil, which is then highly refined and deodorized in our state-of-the-art fish oil refinery," said Ernesto Hernandez, Ph.D., director of process development. "OmegaPure’s EPA to DHA ratio is typically 1:1, and the oil is certified kosher."
Most recently, Hormel Specialty Products, Austin, MN, teamed up with Source Food Technology, Inc., Minneapolis, MN, to offer Eterna omega-3 food ingredients.
"Through a proprietary process, Hormel has been able to commercialize an odorless, tasteless fish oil triglyceride rich in EPA and DHA," said Chet Rao, Ph.D., sales and marketing manager at Hormel. "Eterna food ingredients have very high oxidative stability. The proprietary process eliminates all the free radicals and pro-oxidation species.
Additionally, most of the cholesterol contained in fish oil is removed by this process.
"For baked foods, the oil version of the omega-3 ingredient line is recommended," Dr. Rao continued. "It contains a minimum 30% omega-3. However, encapsulated powder and aqueous dispersion forms are also available."
When using commodity vegetable oils or other ingredients high in PUFAs, adding antioxidants helps prolong shelf life by quenching free radicals, thereby delaying oxidation, degradation and loss of nutrients, pigments and flavors in foods. Bakers can choose between highly effective-at-low-concentration synthetic antioxidants or from a range of all-natural ingredients that possess antioxidative properties.
Kemin Food Ingredients, Inc., Des Moines, IA, developed Fortium brand RPT40 liquid antioxidant for difficult-to-stabilize ingredients such as omega-3 fatty acids. Omega-3 ingredient suppliers can use this ingredient to delay oxidation of these highly susceptible fatty acids. It is also useful in finished product applications, including baked foods made with trans-free, all-natural oils containing noteworthy amounts of omega-3s and omega-6s.
Fortium RPT40 is based on a combination of rosemary extract, tocopherols and ascorbyl palmitate. "Fortium RPT40 enables bakers to protect their investment in omega-3 enrichment, naturally," said Kristen Robbins, associate scientist, Kemin Food Ingredients. Rosemary extract is approved as a natural flavoring in foods.
"Because of active compounds inherently found in rosemary extract, it also can provide protection against oxidative degradation in many applications. Usage levels are higher than synthetic antioxidants for comparable effectiveness, but it does allow for natural labeling. Further, rosemary extract is labeled as a natural flavoring, not a preservative."
The artificial antioxidants that are effective in bakery applications using high-PUFA oils include tertbutylhydroquinone (TBHQ), which is the most effective aromatic organic compound, as well as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT).
As you may have figured, to formulate a baked food with an attractive fatty acid profile, it is imperative that you work closely with a lipid supplier, as well as identify the best omega-3 ingredient for fortification. And never say never to preservatives, especially natural antioxidants that keep lipids from going rancid.