Oil combo to facilitate trans-fat free margarine: study

A blend of canola oil, palm stearin, and palm kernel oil can produce margarine free of trans-fats and desirable textural properties, says new research from the US.

Tapping into the wider industry move to reduce or remove the presence of trans-fatty acids from products, Byung Hee Kim and co-workers from the University of Georgia extended research into the potential of structured lipids (SLs) to provide alternatives to the partial hydrogenation of vegetable oil.

Writing in the Journal of Agricultural and Food Chemistry, the Athens, Georgia-based researchers report that interesterification of canola oil, palm stearin, and palm kernel oil blends, particularly in the ratio 50:30:20 and 60:25:15, produced ‘margarines’ with similar properties to commercial trans margarine fats and commercial trans-free margarine.

“Canola oil, palm stearin, and palm kernel oil-based SLs were suitable for formulating trans-free margarines with low atherogenicity and desirable textural properties,” wrote Kim.

Trans fats and heart health

Though trace amounts of trans fats are found naturally, in dairy and meats, the vast majority are formed during the partial hydrogenation of vegetable oil (PHVO) that converts the oil into semi-solids for a variety of food applications.

Trans fats are attractive for the food industry due to their extended shelf life and flavor stability, and have displaced natural solid fats and liquid oils in many areas of food processing.

But scientific reports that trans fatty acids raise serum levels of LDL-cholesterol, reduce levels of HDL-cholesterol, can promote inflammation can cause endothelial dysfunction, and influence other risk factors for cardiovascular diseases (CVD), has led to a well-publicized bans in New York City restaurants, and other cities, like Boston and Chicago, considering similar measures.

In the food industry this has been mirrored by an increase the in pressure on food manufacturers to reduce or remove trans fatty acids from their products and reformulate.

On-going research

“Margarine manufacturers have also been developing several alternatives to the partial hydrogenation process to reduce or eliminate TFAs in their products, resulting in low-trans or trans-free margarines,” explained the researchers. “The use of structured lipids (SLs) is one of the most successful alternatives.”

Kim and co-workers investigated the potential of the difference blends of the three oils to formulate the trans-free margarines. The heart health properties were determined using fatty acid profiles, while the physical and textural properties of the resulting SLs were also considered.

Our of all the blends tested, the researchers report that the blends of canola oil, palm stearin, and palm kernel oil in the ratio 50:30:20 and 60:25:15 produced margarine-like products with similar properties as those found in commercial margarines containing trans fats or commercial trans-free alternatives.

“Therefore, [CO/PS/PKO-based SLs with ratios 50:30:20 and 60:25:15] were considered to be most suitable for the formulation of trans-free margarines that have low atherogenicity and desirable textural properties,” concluded the researchers.