Olive oil may replace trans-fat shortenings in bakery

Trans-fat containing margarine and other shortenings used in cakes may be substituted by olive oil without affecting textural properties or flavour and aroma, says a new study from Greece.

Despite the strong and characteristic flavour profile of extra virgin olive oil, when used to partially replace margarine in a Madeira cake, a panel of tasters rated the reduced trans fat cake as the most preferred, according to findings published in the LWT - Food Science and Technology.

In addition, researchers led by Adamantini Paraskevopoulou from the University of Thessaloniki also report that substitution with the extra virgin olive oil did not affect the appearance or odour of the final cakes.

Moving away from partially hydrogenised shortening

Shortenings play a key role in cake making by helping to trap air bubble in the batter, which helps with leavening of the product, while also enhancing crumb tenderness, and enhancing moistness and mouthfeel.

However, many shortenings are based on vegetable oils that have undergone partial hydrogenation, a process that converts the oil into semi-solids for a variety of food applications. The process produces trans fats, which are attractive for the food industry due to their extended shelf life and flavour 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 Chicago.

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.

The food industry as a whole has expressed its commitment to removing trans fatty acids from its products, but such reformulation is not straightforward and presents challenges.

Commercial baked goods such as crackers, cookies and cakes, along with many fried foods, like french fries and doughnuts contain trans fats.

In their new study the Greek researchers formulated cakes with margarine only as a shortening, extra virgin olive oil only, or with a combination of margarine and olive oil. Results showed that inclusion of extra virgin olive oil increased the batter density, and boosted the cake volume.

No effect on the appearance or odour of the cakes was recorded, they added. While the cake prepared only with extra virgin olive oil was rated the least preferred by a panel of 20 tasters, the score was “very close to those obtained for the control cake”, wrote Paraskevopoulou and his co-workers.

“Attending overall liking, the cake prepared with extra virgin olive oil/margarine mixture was the most highly preferred by the panellists,” they added.

Source: LWT - Food Science and Technology

Published online ahead of print, doi: 10.1016/j.lwt.2010.02.002

“Aroma and physical characteristics of cakes prepared by replacing margarine with extra virgin olive oil”

Authors: A. Matsakidou, G. Blekas, A. Paraskevopoulou