Fats, Oils and Omega-3s
Overview of Fats and Oils Used in FoodsFats and oils come from a wide range of sources. Edible oils may be derived from animals (tallow and lard), seeds, nuts, fish and fruits. Before globalization, people used oils indigenous to their part of the world. When formulating with fats and oils, it behooves the user not only to understand the oils they are using, but the systems or products in which they will be used.
Fats and oils consist of triglycerides, three fatty acids attached to a glycerol backbone. The fatty acids attached to the backbone may be saturated; that is, there are only single bonds between all the carbon atoms on the chain, or unsaturated. Unsaturated fatty acids have one or more double bonds between the carbons.
The degree of unsaturation affects the physical characteristics of the oil and, hence, its functionality. The greater the degree of saturation, the harder the fat will be. The hydrogenation process allows oil processors to modify edible oils selectively. Hydrogenated oils can be fully saturated or partially saturated.
Hydrogenation also modifies unsaturated fatty acids so they appear in the trans form. Trans fatty acids behave like saturated fats in terms of both functionality and how the human body metabolizes them. This has led the industry to search for alternatives to oils containing trans fatty acids, such as palm and palm derivatives and interesterified oils.
Edible oils may also be plasticized by passing the products through a continuous-scrape surface heat exchanger and injecting nitrogen. Users need to understand the physical characteristics of the oils they are using, since not all fats and oils are interchangeable.
Low-linolenic Soybean Oil: A New and Healthy OptionBunge Foods and DuPont Biotechnology have joined forces to create a new proprietary low-linolenic soybean oil that could help alleviate health concerns posed by trans fatty acids. Since the development of the hydrogenation process over 100 years ago, the edible oil industry has utilized it to create a wide range of fat and oil products with unique functional properties, noted Troy Hobbs, business manager with Bunge DuPont Biotech Alliance, who spoke on the benefits of the oil.
However, recent research in Europe and the U.S. has indicated that hydrogenated fats and oils pose a potential health risk due to the trans fats created when oils are partially hydrogenated. Trans fats act very much like saturated fats in that they increase the risk of cardiovascular disease. The new product, now under cultivation in areas around Creston, Iowa, and Marion, Ohio, yields a finished product significantly lower in linolenic acid than traditional soybean oils. This new product does not require hydrogenation to ensure stability. The reduced levels of linolenic acid help enhance the stability of the oil during deep-fat frying and minimize the potential for oxidation. Beginning in 2006, when new FDA regulations requiring the labeling of trans fats go into effect, users also will be able to avoid having to declare any trans fatty acids in the foods that use or are fried in the oil. The partners plan to significantly increase acreage dedicated to the new product over the next five years. Their goals are to ramp up production to 1,000 million pounds by 2010. Growers whose products are less than 3% linolenic acid will be paid a premium.
Formulating Dairy Products with Omega-3 Fatty AcidsA myriad of studies, both clinical and other, have been conducted using omega-3 fatty acids from fish oils over the past 20 years. These studies, which used oils with both eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), imply that diets containing these fatty acids can enhance cardiovascular health as well as promote many additional health benefits. Omega Protein Inc., a manufacturer of omega-3 fatty acids, has formulated these compounds into a range of products including dairy products, salad dressings, spreads, liquid eggs and baked goods.
According to Valerie Sanders, food applications scientist for Omega Protein, fish oils with omega-3s can be formulated into dairy products such as fluid milk, yogurt, cheese and smoothies. With any long-chain polyunsaturated fatty acid, such as those found in fish oil, it is best to avoid excessive exposure to heat, light, air and metals. Under optimal conditions, products containing long-chain omega-3s should be mixed in covered vessels at the lowest possible temperatures for that specific process, taking care to provide minimal exposure to the environment. When adding omega-3 fish oils to dairy products, they should be added toward the end of the process. The use of chelating agents or additional antioxidants also is recommended, to minimize the potential for oxidation. Formulating yogurts, smoothies and other dairy products with refined fish oils containing omega-3 fatty acids creates products that combine the benefits of both dairy and fish.
Benefits of a Structured LipidStructured lipids are oils that have been randomized to yield an end product with specific functions and health benefits. Dilip Nakhasi and Roger Daniels of Bunge North America described how they used the interesterification process in utilizing high-oleic canola oil plus medium-chain triacylglycerols and physically blended in plant phytosterol esters to produce a new product. Each of the three components making up the new product has shown distinct health benefits, but how they work in combination is unknown. To evaluate the efficacy of the new product, the company funded human clinical trials comparing diets containing the interesterified product with extra virgin olive oil. Researchers evaluated parameters related to plasma lipids in hypocholesterolemic men. Men who received the new oil in their diets had improved total cholesterol, low-density lipoproteins and triglycerides. The diet with extra virgin olive oil had a reduction in high-density lipoproteins (HDL, the “good” cholesterol), although not statistically significant. Participants receiving the diet with the new oil also lost more weight on the average, and had increased energy expenditure.
Bunge's scientists feel the new product can be used for stir-frying, pan-frying, cake mixes, marinades and salad dressings, and it performs especially well in recipes utilizing chicken and vegetables. The company feels that marketing the new product with plant sterols esters in glass packaging that resembles olive oil products will help them compete with olive oil, which is known by most consumers as a healthy oil. By demonstrating that interesterified oils with plant sterols esters are even healthier than olive oils, market penetration should increase.
Omega-3 StabilityScientific research indicates that long-chain omega-3 fatty acids have a positive impact on a wide range of health conditions. These include regulation of blood pressure, diabetes, osteoporosis, skin health, prostate cancer and a number of others. According to a 2004 Health Focus Report, omega-3 fatty acids are the second most sought-after ingredient. Dr. Lucia Ponginebbi of the National Starch Food Innovation group expounded on the benefits of encapsulating long-chain omega-3 fatty acids.
The encapsulation process protects the omega-3s from the environment (reduced oxidation potential), improves stability through processing, extends product and ingredient shelflife and reduces the potential for off-notes in the finished product. Encapsulation yields stable, free-flowing powder that can be incorporated easily into many different kinds of baked goods.
How encapsulated omega-3 fatty acids are used in baked goods depends upon the product and how it is processed. Moisture in the product, pH, product temperature and baking time all affect how much of the added omega-3 is retained in the finished product. As an example, Ponginebbi stated that a baked product like bread retained 85% of added omega-3, whereas a non-baked item like a nutrition bar had 97% retention. She emphasized the importance of flavor stability in any application using omega-3 fatty acids.