‘Liquid shortening’ may reduce saturated fats and improve cake quality, suggests study

22 April 2011

Foodnavigator.com (22/4/2011) reported on a study published in LWT - Food Science and Technology, that found cakes made from liquid shortening containing a zero trans-fats, and generally a healthier fat profile, showed more uniform grain, finer texture, higher volume, and better shelf-life then cakes made from plastic shortening.

The researchers, based at department of grain science & industry at Kansas State University, explained that as industry moves away from the use of trans-fats in its formulations, it is important to look at the properties of replacement ingredients, in order to achieve the most effective yet healthy profile. As many companies moved to the relatively inexpensive palm oil instead of hydrogenated soybean oil to make zero-trans fat shortenings. Ironically, the high levels of saturated fatty acids in palm oil result in the same cardiovascular problems as do trans-fats.  For baking companies, a liquid oil plus an emulsifier combination blend would be easy to handle and they could combine different emulsifiers as their requirements change, although this would require investment in equipment, and a skilled staff to prepare such shortenings.

Shortening is generally a semisolid fat for use in food preparations, especially of baked goods; so called because it promotes a ‘short’ or crumbly texture. In high-ratio layer cakes, shortening is a major ingredient and has  three basic functions; it traps air during the creaming process, coats protein and starch particles, and emulsifies large amounts of liquid. Solid ‘plastic’ shortenings are the most commonly used type of shortening in the baking industry, although they often contain high proportion of hydrogenated fats, including trans-fats. Research has showen that trans-fats in the diet may increase the risk of coronary heart disease, by raising the levels of LDL cholesterol and lowering the levels of HDL cholesterol.

The ‘liquid’ cake shortenings function much like solid shortenings in baking systems, but they offer advantages, including having a healthier fat profile.

For the study four groups of layer cakes were baked using: plastic shortening, liquid shortening, liquid oil, or liquid oil plus emulsifier combinations. Cake performance and firming over-time were then evaluated. The results showed that liquid shortening provided the best fresh cake characteristics, whilst liquid oil provided the worst fresh cake characteristics. Cake firmness was found to change slowly during storage for cakes made with liquid shortening, but for cakes made with liquid oil, firmness increased rapidly.The characteristics and changes in firmness for plastic shortening were said to be “intermediate.

The researhcers concluded that liquid oil alone “is not suitable for use in cake making”, but that a blend of oil and emulsifiers was found to produce high quality cakes.This suggested that emulsifiers played an important role on the improvement of cake firmness shelf-life.

 

Journal: LWT - Food Science and Technology
Published online ahead of print, doi: 10.1016/j.lwt.2011.03.013
“Evaluation of different types of fats for use in high-ratio layer cakes”
Authors: J. Zhou, J.M. Faubion, C.E. Walker