Oil Technology in Food Product Development
Demonization of oils and fats has retreated, but lipid technology is still going strong
Most American consumers have learned that fat is not to be feared and is a necessary component of the diet. Still, calories-per-serving remains important, and fats have more than twice the calories per gram as do carbohydrates or protein.
The source of the fat is also paramount—whether from a plant with a health cachet (e.g., avocado, coconut); non-GMO stock; or a particular fat structure (saturated vs. unsaturated). The need for attractive oils that provide or enhance a desired set of functions, from textural to organoleptic to metabolic, is driving technologists to develop multiple new takes on oils and fats for preparation and use in food and beverage formulations.
According to last year’s USDA Oil Crops Yearbook, the most widely used fats and oils in the US are, in order: soybean, canola, corn, palm and palm kernel oil combined, tallow, and coconut. Lard, olive, cottonseed, sunflower, peanut, safflower, and sesame follow in decreasingly fewer amounts. Of these, soybean oil is the most ubiquitous.
Many manufacturers rely on soybean oil, often labeled as vegetable oil, at a rate of almost four times the second-most common oil, canola. Of all oils, consumer and commercial, consumed in the US, some 55% are from soybeans. Soybean oil’s most attractive characteristics are its competitive price, reliable domestic supply, neutral flavor, versatility, blendability, and its emulsifying quality for foods such as mayonnaise.
Soybean also contains lecithin, commonly removed in oilseed processing, then added back to the oil. Use of the lecithin eliminates the need for the chemical antioxidant and preservative tert-butylhydroquinone (TBHQ).
TBHQ increases shelflife but is not a clean label ingredient. Soybean oil also has the highest level of the tocopherol form of vitamin E. These function as natural antioxidants, also allowing a cleaner label.
Local sourcing also helps drive sales: According to a recent United Soybean Board survey, 83% of consumers reported that it is important to support domestic agriculture by buying foods produced with crops grown by US farmers.
Soybeans are a biotech crop, and there have been significant plantings and research in the past 10 years in high-oleic (monounsaturated) soybean oil (HOSO). This work began as an effort to provide the food industry with a better-for-you alternative to partially hydrogenated (PHOs) and highly saturated oils. According to the United Soybean Board, high-oleic soybeans are on track to be the fourth-largest row crop in the US by 2023.
Research on HOSO has shown it to perform on par with high-oleic sunflower, considered the gold standard oil, in oil fry life, color, and taste. When polymerization was tested after 24 days of frying with HOSO, there was less than 5% polymerization on the equipment surface, leading to fewer maintenance costs.
The High Cs
Corn oil once jockeyed for position as the second-most popular vegetable oil, but today, canola carries that distinction. It is the third-most consumed vegetable oil in the world.
The crop was developed in Canada in the 1970s, using traditional plant-breeding techniques, with biotech varieties entering the scene in 1995. It has the least saturated fat of any common culinary oil; a high smoke point; and is shelf-stable without being hydrogenated—allowing it to be made into a trans fat-free shortening. A recent development is the successful high-oleic canola oil. The product has proven to not only be healthful, but superior for frying and spraying.
According to Patti Miller, MSc, president of the Canola Council of Canada (CCC), “High-stability canola oils were developed to be higher in oleic acid, a monounsaturated fatty acid. This provides even greater heat tolerance and longer storage stability and makes it ideal for food processing and foodservice applications.”
The list of foods containing corn oil are the same as those designated for canola oil. Corn oil can lay claim to having the second-highest level of healthful phytosterols in oil—only rice-bran oil is higher.
Corn oil also is a good source of linoleic acid, an essential fatty acid. It also is good source of tocopherols. Corn oil still is favored as an excellent frying oil, with a smoke point of 450˚F. Its neutral flavor and aroma make it highly suitable for salad dressings and shortenings.
Whether coconut oil, coconut milk, or coconut water, there’s no escaping the coconut trend. Coconut oil, a naturally healthy saturated fat (predominantly lauric acid), has benefited greatly from that trend, as well as the anti-trans fats movement. Coconut oil, extracted from the kernel or meat of the coconut shell, now comprises about 2.5% of the world’s vegetable oil production. Both virgin coconut oil—with a flavor and aroma—and RBD (refined, bleached, and deodorized) are available.
In spite of interest in coconut oil, global production is declining, from 6.13MMT in 2012-2013, to a forecast of 5.4MMT for 2015-2016. This probably will result in higher prices. The 18-member Asian and Pacific Coconut Community (APCC) produces about 90% of the world’s commercially sold coconut oil and sets standards for virgin coconut oil.
Coconut oil contains 92% saturated fat—higher than butter, lard, or tallow. Because of the high saturated fat content, it is slow to oxidize and turn rancid, with a shelflife of about six months at 75˚F. Its smoke point is on the low side, at 351˚F, and its melting point is quite low—at 76˚F. Hydrogenation brings the melting point to 97-104˚F and will prevent products in warm climates from melting. However, hydrogenation converts the unsaturated fats into trans fats.
Currently, coconut oil has become a favored frying oil, especially in South Asian formulations. It also is popular for use in baked goods. In a study of 148 consumers published earlier this year in the Journal of Food Science, researchers compared sponge cake (with 20% whole-wheat flour) made with extra virgin coconut oil (EVCO), extra virgin olive oil (EVOO), and rice bran oil (RBO), and compared them to butter as the control, evaluating acceptability across 9 sensory attributes on a 9-point hedonic scale; 8 emotion responses on a 5-point rating scale; and purchase intent on a binomial scale. Overall liking, emotion, and purchase intent were evaluated and compared before and after a health benefit statement of oils had been given to consumers. Overall scores of liking and positive emotion (except “calm”) of the sponge cake made with EVCO were higher than those made with EVOO and RBO. Researchers also found that volume, expansion ratio, and moisture content of the EVCO and EVOO products were not significantly different, but higher than the RBO. An “oil health benefit statement” provided to the panel significantly increased the overall liking, positive emotion, and purchase intention scores of the oil-based cakes.
Under the Palms
Another naturally saturated tropical vegetable oil has experienced a jump in consumer awareness and usage, but not without controversy: palm oil. Together, palm oil and palm kernel oil are the fourth-largest consumed oil type in the US. Primarily produced in Malaysia and Indonesia, other markets especially African and South American—have been moving into gaps created by fair trade and ecological controversies that have arisen with Asian-sourced palm oils.
Palm oil is produced by processing the mesocarp (reddish pulp) of palms. Each mesocarp has about 1,000-2,000 fruitlets with a kernel in the center. Palm kernel oil comes from these kernels and contains about 81% of saturated palmitic acid. Palm oil is about 44% palmitic; 37% oleic (monounsaturated) and 9% linoleic polyunsaturated.
Red palm oil is produced retaining more of the carotenoid complexes (vitamin A-like compounds that show a variety of strong health benefits) from protecting against cancer, heart disease, and macular degeneration, as well as reducing blindness in the underdeveloped countries where diets tend to be low in vitamin A. The red palm oil also contains the carotenoid lycopene and is not only high in the tocopherol forms of vitamin E, but also very high in tocotrienols.
Palm oils primarily are used in margarine spreads, shallow frying, fillings for creams in biscuits, doughnuts, cakes, pastry dough, chocolates, mayonnaise, salad dressings, non-dairy whipping toppings, coffee whiteners, and ice cream. Both oils are commonly refined, bleached, and deodorized. Palm oil often can be the least expensive vegetable oil for commercial use.
The palm oil industry is under attack from many environmental groups because of its deforestation in Malaysia and Indonesia, putting the orangutan, Sumatran elephant, and tiger—as well as hundreds of other animal, reptile, avian, and insectoid species—at high risk for extermination. Indigenous people also are endangered, and significant greenhouse gas emissions are increasing global warming.
In recent years, the Malaysian government has committed to preserving more forest land and a certified sustainable palm oil label (CSPO) is available from the Roundtable on Sustainable Palm oil (RSPO). This organization appears to be the best sustainability entity in Southeast Asia. RSPO has more than 550 members, but less than 20% are producers, as it is multi-stakeholder and includes the entire chain—from growers and producers to retailers, buyers, governments, and NGOs.
One of the major complaints about the RSPO is that it still permits planting on the peatlands and cleared secondary forests. Peatlands play a major role in storing the world’s carbon, which will be lost if the peatlands are destroyed. Because it operates “by consensus,” RSPO is slow to make changes, but it has been beneficial. The government of Indonesia put a moratorium on the clearing of new forest, which was in effect from 2011-2015. However, a study by the University of Maryland shows that deforestation actually increased during the moratorium.
The oil palm is native to West Africa, and companies are moving there from SE Asia. Currently, there are 1.8 million hectares (4.5 million acres) in production, and half of that encroaches on the habitat of the great apes. Another 1.4 million hectares (3.5 million acres) are being requested by the oil companies. In 2012, Norway’s government pension fund pulled out of 23 palm oil companies (two of which belong to RSPO), deeming them unsustainable.
Companies also are in South America, primarily in Columbia, but expanding to Ecuador and Brazil. The harvested acres of palm oil trees doubled between 1990-2010—still a small percentage compared to soybeans, corn, and sugarcane. Currently, most plantations are on former rain forest lands but are shifting to less-productive pasture land. The same concerns about animals, humans, and global warming apply to Africa and South America.
Thomas Jefferson attempted to introduce olive oil into America as a substitute for lard and for a cheap margarine-type food for his slaves. The periodic freezes and high humidity of Virginia, however, prevented the groves from thriving. Most of the world’s olive oil comes from the Mediterranean region, as well as California. However, places with similar climates, including Australia, Texas, Mexico, and South Africa, have been growing olives. Other regions of Africa, Japan, and China are slowly inching into the game.
Olive oil is known for its unique flavor and stability, both of which vary with the degree of extraction. Extra virgin oil (EVOO) is extracted at the first pressing, and subsequent pressings produce lower quality, affecting both taste and price. EVOO also is the most nutritious, containing more antioxidants. Both the quality and processing is defined by Codex Alimetarius regarding physical and chemical properties.
Olive oil is high in monounsaturated fatty acids and is primarily used for upscale salad dressings and in restaurant meals and sauces. It also is a popular retail cooking oil. The smoke point of olive oil ranges from 320-405˚F, depending on the crush level and acidity. Pomace, derived from the olive pulp after the first pressings, has a smoke point of 460˚F.
Approximately 5-8% of the oil remains in the pulp, so solvents are added to extract the remaining oil. This is an industrial technique used in the production of many other edible oils. However, if no solvents were used in the extraction, the International Olive Council permits it to be labeled “olive oil.” Avocado oil has many properties similar to olive oil and is enjoying growing use in snacks, such as crackers and potato chips. It has a high smoke point and a rich flavor.
Nuts and Flowers
Sunflower fields throughout the Dakotas and Midwest blanket the landscape with unbelievable beauty—and the finished oil is nutritious and highly functional.
“Many manufacturers are switching to sunflower oil, since it is non-GMO—good for clean labeling—and has a longer fry-life and shelflife than many other oils,” says John Sandbakken, executive director of the National Sunflower Assn. Also, sunflower oil is high in vitamin E, which confers its own health benefits.
Currently, 52% of US-processed sunflower oil is exported to Canada, while Mexico is the number-two buyer. There is a limited amount of organic sunflower oil available. The four types of sunflower oil currently available are:
- High-linoleic: available only in small quantities in the US, due to its limitations for frying.
- Mid-oleic: the main “go-to” sunflower oil, with good shelflife and excellent frying capability. It has a neutral taste and is 65% oleic, 26% linoleic, and 9% saturated.
- High-oleic: Oleic levels are 82-90%, which adds stability and allows a smoke point of 440˚F. The typical profile is 82% oleic, 9% linoleic, and 9% combined saturated fats.
- High-omega-9 (92% oleic acid) sun oil, with only 3% saturated fat, is being developed and will be available in a few years.
A 2014 study by [WHO] demonstrated that, when 60-70% of the butter in a shortbread formulation was replaced with high-oleic sunflower oil, the saturated-fat content was reduced, yet the shortbread was similar in sensory perception and maintained a similar shelflife.
Safflower, a thistle-like annual with yellow, orange, or red flowers, grows well in arid environments. India, the US, and Mexico are the world’s leading producers of safflower oil. It comes in both high-linoleic and high-oleic varieties, and a high-oleic organic product recently has been made available. All are low in saturated fats (7.5-9%)—lower than the majority of oils. The smoke point of refined safflower oil is notably high—510˚F.
Because of its high smoke point, safflower is excellent for frying. Salad dressings, margarine and baked products also use safflower oil. It has a shelflife of 12 months, if stored in tightly sealed containers; out of direct light; and in temperatures not higher than room temperature, although refrigeration is recommended (as it is for most oils).
One of peanut oil’s most attractive qualities is its high smoke point—440˚F—which is great for deep-fat frying. Peanut oil is high in monounsaturated, oleic fatty acid (47-49%), with about 33% from linoleic acid. The remaining 18% is saturated, primarily palmitic acid. Although a good source of vitamin E, extra vitamin E is often added to increase shelflife to about nine months under ideal conditions and longer.
Unrefined peanut oil is becoming more popular among consumers, as are all unrefined oils. Also, a specialty oil made from roasted peanuts, and, hence, a more pronounced flavor, is being used more often, especially for Southeast Asian recipes.
Sesame oil has a distinctive aroma and flavor, making makes it popular as a cooking oil in Southeast Asian cuisines. The color varies from light made from unroasted seeds to a deep reddish yellow if the seeds were toasted before crushing. The oil can be also bleached. Sesame oil is highly stable due to the inherent antioxidants in the lignans. The lighter, refined oil has a higher smoke point (450˚F), making makes it a good deep frying oil while the smoke point of unrefined oil is 350˚F, thus better suited for stir-frying, sautéing, and use directly in sauces or dressings.
Sesame oil contains a variety of nutritional components, including vitamins (E and K), phytosterols, and lignans. The lignin content increases during the extraction process. These antioxidants help prevent rancidity in an oil containing 35-54% oleic, 39-59% linoleic, and up to 15% saturated fatty acids.
A number of other oils are moving to the front of the shelf for both consumers and processors. Nut and seed oils (from such flavorful and healthful products as walnut and hazelnut oil, to pumpkin seed and the trendy argan, moringa, hemp, chia, and flax oils), as well as oils from fruits and vegetables (i.e., cranberry seed and carrot seed oils) are trending up in dressing and high-end sauce applications, and simply as supplements taken in the same manner as fish oil. Other oils from sources such as rice bran and wheat germ oil are carving out a corner of the market in premium processed foods as a healthful incentive.
With more realistic approaches to fats and oils in food processing and preparation, consumers are able to accept a greater variety of options that promise both flavor and functionality on multiple levels. Oil technologists also continue to push the envelope on ingredient development, to give processors and end-users the best of both.
Originally appeared in the May, 2016 issue of Prepared Foods as Slick Talk.
For several decades, consumers have shunned solid animal fats, in order to avoid saturated fat and cholesterol. Recently, however, butter consumption in the US has increased from 4.5lb per person in 2000 to 5.5lb in 2014-2015. The revival of interest in solid animal fats is likely a combination of the updated science that reveals a place for moderate intake of saturated fats in a healthy person’s diet; the economic push toward increased demand for comfort foods; and just plain flavor.
There are some obstacles for using butter in commercial applications. Cost is one; the need to affix an allergen warning (contains milk) another. And, butter’s low smoke point prohibits high frying temperatures. However, the smoke point is variable, depending on whether it has been clarified, according to Rohit Kapoor, PhD, of Dairy Management Inc. (DMI). The smoke point of butter is “around” 300˚F, yet even that varies, depending on how it was clarified, how long it was stored, any impurities, etc. The melting point of butter is approximately 95˚F—a benefit for confectionary coatings that require a melting point close to body temperature (98.6˚F), so they do not leave a waxy mouthfeel.
Butter also works in chocolate to stabilize its matrix and help prevent bloom (a whitening of the surface). Butter also is excellent for use in cookies and certain cakes and, especially, in laminated pastry formulations, such as croissants and puff pastries, since the dough must be plastic, yet firm enough to avoid melt off. And, of course, butter works especially well in dairy products, such as cream icings, fillings, and ice cream/ice cream novelties. In savory items, especially cheese sauces and fillings, butter adds smoothness, stability, and a highly desired, velvety mouthfeel.
Tallow and lard, too, are becoming popular, with applications mostly at the restaurant level. The former is seeing growth in popularity, as an additive to frying oil to enhance flavor and crispness. The latter is increasingly used to make more authentic, flaky “home-style” pie and short-pastry crusts.