Researchers from the University of Guelph in Canada report that so-called two-stream ice creams made from a mixture of fractionated palm kernel oil, high oleic sunflower oil and glycerol monooleate favoured the formation of “desirable ice cream”.
Writing in the International Dairy Journal, the researchers note that consumers are increasingly seeking out healthier versions of their favourite foods, including ice cream. For ice cream, saturated fats may be substituted by unsaturated oils like high oleic sunflower oil, but this changes the structure of the ice cream, and “result in a product with less body, which is also perceived as less creamy”.
“Hence, the replacement of solid fat with ‘healthier’ or liquid fractions is a major challenge in the production of high quality ice cream because the texture, probably the most sought after quality in this product, is highly compromised,” explained Carlos Mendez-Velasco and Douglas Goff.
“This study aimed to produce acceptable ice cream with lower amounts of solid fat in higher unsaturated fat formulations.”
The Guelph-based scientists prepared a range of ice creams with 10% fat content, using different levels of palm oil (saturated fat, ACH Food Companies Inc.), sunflower oil (unsaturated, Nealanders International Inc.) and the emulsifier glycerol monooleate (Danisco).
“Emulsions containing saturated fat or unsaturated oil were combined in the preparation of ice cream; solid fat droplets contributed to the structure-forming properties and stability while protein-stabilised liquid droplets acted as inert fillers, producing so-called two-stream ice creams,” explained Mendez-Velasco and Goff.
Results showed that the two-stream ice-creams were not any different from control ice creams in terms of particle size or melt stability.
Increasing the level of glycerol monooleate was associated with greater particle size and higher destabilisation of the formulation, which was considered a good thing as it was linked to an increase in creaminess of the finished ice cream.
The study was funded by Nestec.
Source: International Dairy Journal
August 2011, Volume 21, Issue 8, Pages 540-547
“Enhancement of fat colloidal interactions for the preparation of ice cream high in unsaturated fat”
Authors: C. Mendez-Velasco, H.D. Goff