|Replacing trans fats: New crops for heart-healthier oils|
|Thursday, 10 May 2012|
Dow Chemical and DuPont are launching new seeds that promise oilseed crops with improved fatty acid profiles — and with resulting vegetable oils that will benefit both food makers and public health. The seeds — soybean from DuPont and canola and sunflower from Dow — yield crops with a higher proportion of monounsaturated oleic acid.
The two companies developed the new oils as alternatives to partially hydrogenated vegetable oils, which contain unhealthy levels of trans fats. In January 2006, the Food & Drug Administration began requiring food manufacturers to list trans fat contents on product nutrition labels. The rule came after years of mounting evidence that the use of partially hydrogenated vegetable oils has negative heart-health effects due to the trans-fatty acids formed in their production. Food makers have struggled to replace trans-fat-containing oils and shortenings; if they embrace high-oleic oils from Dow and DuPont, the products will win a huge market.
The stories the two companies tell about their products are similar, with one notable exception. Whereas Dow achieved its Nexera high-oleic-acid canola and sunflower traits through plant breeding, DuPont’s improved Plenish soybean got that way through genetic engineering.
The companies are first eyeing the markets for frying and other liquid-oil applications. For applications such as baking that require solid shortening and may still involve some amount of trans fat, the new products will likely be blended with established trans fat replacements, namely palm oil and interesterified oils, which are processed vegetable oils that do not contain trans-fatty acids.
Crop acreage is ramping up, and in the next few years significant quantities of the new oils should hit the market, experts say. The opportunity is large: Roughly 22 billion lb of vegetable oils are used for food making in the US annually.
“It’s too early to assess today’s market size for these next-generation products. They won’t be commercially launched until 2013. But yes, they will replace existing oils,” predicts Shahana Malik, food analyst at the consulting firm Nerac.
“The food industry has moved into the change and is excited about it. With 40 food manufacturers experimenting with Plenish, it is clear they are willing to make this change.”
Replacing trans fat in food products is not easy. Trans-fatty acids are formed when vegetable oils are partially hydrogenated. And food makers love the qualities this transformation brings: Liquid oils become solid at room temperature, melting at higher temperatures such as when in the mouth or in the oven.
Partially hydrogenated vegetable oil has been part of the American diet since the early 1900s. Crisco, made from partially hydrogenated cottonseed oil, was launched in 1911. Until recently, partially hydrogenated oils were widely used in preparing restaurant foods such as french fries, as well as snack foods and baked goods.
According to the Harvard School of Public Health, about 4 to 7% of the calories from fat consumed in the US during the early 1990s were from trans fat. FDA and the Institute of Medicine now say consumption of trans fat should be “as low as possible.”
In partial hydrogenation, hydrogen is added to liquid oil under pressure and in the presence of a catalyst. The process breaks some carbon-carbon double bonds in the fatty acids of the oil and adds carbon-hydrogen bonds. Partial hydrogenation increases not only the oil’s melting point but also its shelf life. With fewer carbon-carbon double bonds, partially hydrogenated oil takes longer to become rancid than unhydrogenated vegetable oil. In the process of partial hydrogenation, however, a large number of the remaining double bonds isomerize and assume the unnatural trans configuration, instead of the naturally occurring cis configuration.....
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