Technical Talk: May 2009
April 29, 2009
By Dr. John Michaelides
Continuing our series on the basic ingredients of baking, what is the function of fats and oils in baking, what is new in this area of health research and what are the alternatives?
Oil, shortening, butter and margarine are essential baking ingredients. These fats play a substantial role in making good bread, cookies, cakes and many other baked goods our customers enjoy.
Fats share a common general chemical composition with variations that can contribute negatively and positively to people’s health, but they often function and behave differently. They mainly contain triglycerides, which are basically a combination of a glycerol molecule with three fatty acids attached, forming a tail configuration. The composition and characteristics of the fatty acid tail determines the fat’s behaviour as a functional ingredient as well as its effect on human health.
In this article I will not discuss in detail the different types of fatty acid composition but rather examine how these ingredients relate to health issues and behaviour in the food we eat.
A major concern of the medical profession is our over-consumption of fat, especially unhealthy fats such as saturated and trans fats. Fats contain more calories than proteins and carbohydrates. Thus, many food manufacturers are trying to reduce or eliminate unhealthy fats in their products and at the same time provide the consumer with great-tasting foods.
Fatty acids, the major components of fats and oils, can be classified as saturated, mono or polyunsaturated according to the absence or presence and the number of double bonds found in their hydrocarbon chain. Saturated fats are normally hard fats that are solid at room temperature while unsaturated fats and oils are usually liquid.
A key requirement of the application of fats in the formulation of baked goods is the fat’s melting point. Different baked goods require fats that melt at different temperature regimes. The hydrogenation process was developed many years ago to provide the flexibility of variable melting points to satisfy the food industry needs. In addition, hydrogenation of vegetable oils eliminated concerns about cholesterol. However, the process of partial hydrogenation results in trans fats, which have been identified as a major contributor to health problems such cardiovascular disease.
Fats and oils as ingredients for the baking industry are of different importance depending on the finished product. By far the most functional fats in baked good formulations are shortenings. Shortenings are essential because they perform many important functions in the process of baking: They tenderize and add shortness to the structure of the crumb, help in the aeration of the product during mixing, help stabilize batters and creams by the process of emulsification, improve palatability and help extend the shelf life of the product.
Recently, because of the health problems blamed on trans fats, alternatives to traditional shortenings are being sought, but this has been proven difficult. Significant progress has been made with processes such as enzymatic interesterification, which results in shortenings with no trans fats and blending processes that reduce the amount of trans fats created.
The greatest challenge, however, is finding alternatives for cakes, laminated doughs and puff pastries. But progress is being made toward this goal. Many manufacturers and suppliers have shortenings with reduced trans fats available for use in different applications. Recently, a new nonhydrogenated margarine called Novarin, with nearly zero trans fats, has been touted as a replacement for normal margarine on a one-to-one basis in puff pastry, thereby reducing saturated fat or eliminating it completely. No details of this technology, which originated in the Netherlands, have been revealed, but it is rumoured to be based on the specific blending of oils and the interaction of water with emulsifiers and fat.
New research from India suggests that 50 per cent of fat can be replaced in cakes with sesame oil in combination with hydroxypropylmethylcellulose (HPMC) and Sodium Stearoyl-2-Lactylate (SSL), resulting in high-quality cakes. Using sesame oil also decreases the use of saturated and trans fats in addition to boosting the essential fatty acid content in cakes.
As an alternative to seeking oils and fats that perform well and do not present any health issues, food manufacturers may choose to replace fat with other ingredients. Many ingredients are available to enable the bakers to reduce or eliminate fat in baked goods. We don’t have space to discuss all the options here, but there have been a few key developments. For example, Sta-Lite, a polydextrose from Tate & Lyle, can replace fats and sugars and add fibre while maintaining body and texture in food products. It is also considered to be a prebiotic fibre with only 1 kcal per gram. Another fat replacer, Soft’R Slim from Puratos, a combination of emulsifier technology with enzymes and flavours, has been claimed to help reduce the fat content of baked goods without compromising the taste and texture.
Other new developments in the area of fat and oil ingredients include the incorporation of omega oils in baked goods. These oils are added primarily to make the products healthier for the consumer. However, they present major challenges to the baking industry, especially in delivering proper health benefits and oxidative stability – but without fishy flavours. Sources of omega oils include flax seed, fish oil, algae and fungi. Recent developments in micro-encapsulation of omega oils allowed the successful incorporation of these oils into baked goods and many other food products.
Benefits, health concerns and challenges abound when considering how best to incorporate oils and fats in baked goods. Therefore it’s essential to be aware of the ingredient options when embarking on the development of new products or reformulating your existing ones.
Funding for this report was provided in part by Agriculture and Agri-Food Canada through the Agricultural Adaptation Council’s CanAdvance Program.
Dr. John Michaelides is Guelph Food Technology Institute’s director of research and technology. For more information, or fee-for-service help with product or process development needs, please contact GFTC at 519-821-1246 or email@example.com.
Correction: Due to a copy-editing mistake, last month’s Technical Talk said Tate & Lyle’s Sta-Lite polydextrose “delivers fewer calories and less fibre.” The text should have read, “delivers fibre and fewer calories.” Bakers Journal apologizes for the error.
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