Scientists optimise palm and sunflower oil-based ice cream
A blend of highly saturated palm kernel oil and monounsaturated high-oleic sunflower oil containing 60 to 80 per cent solid fat was found to produce the best results, according to new results in the Journal of Food Science that could help manufacturers select “appropriate fat blends for nondairy-fat ice cream”.
“This study should be of great commercial interest to the ice cream industry,” wrote Kristine Sung and Douglas Goff from the Department of Food Science, at the University of Guelph in Ontario.
“In North America, there is a growing trend toward the manufacture of frozen desserts in which nondairy fats are replacing milk fat, similar to the trends that have occurred in Europe in the last decades.
“These results will help manufacturers to optimize the blend of fats for both functionality and cost,” they added.
The results could be of particular importance in the UK following recent claims by Unilever that aligning the UK with Europe over definitions of ‘ice cream’ would give manufacturers more of an incentive to reformulate.
Under UK law – enshrined in the Food Labelling Regulations (1996) – products called ‘ice cream’ must contain at least 5 per cent fat and 2.5 per cent milk protein.
Elsewhere in Europe, the European Ice Cream Association’s (Euroglace) code of practice for edible ices typically applies. This requires ‘ice cream’ to contain fat (from dairy, eggs or vegetables) – but does not set a minimum fat or protein level.
The new study, partly funded by the Canadian Dairy Commission, looked at producing fat networks composed of palm and sunflower oil instead of dairy fat. The solid fat content, dictated by the palm oil, was varied from 40 to 100 per cent.
According to the findings in the Journal of Food Science, blends made of 60 to 80 per cent solid fat were found to produce the most desirable ice cream, as shown by the lowest rates of meltdown, as well as the smallest sizes for air bubbles.
Sung and Goff also noted that the results will help with the development of strategies to replace saturated fats, and the structural role they play in products like ice cream, without sacrificing on quality.
“This might allow for the addition of highly unsaturated oils, like omega-3 fish oils, in ice cream formulations,” they added.
An area of increased interest
The research taps into ongoing innovation in ice cream formulation. Unilever was granted EU novel foods approval just under a year ago (May 2009) for the ingredient Ice Structuring Protein (ISP), used in ice cream to reduce fat content and improve stability.
The ISP ingredient, already used in products markets such as the US, Australia and Mexico, can reportedly help reduce the fat and calorie content of products by up to 50 percent. Its ability to improve the stability of ice cream also allows for a higher fruit content, an improved taste, better structure and slower melting, claims Unilever.
Source: Journal of Food Science
Published online ahead of print, doi: 10.1111/j.1750-3841.2010.01539.x
“Effect of Solid Fat Content on Structure in Ice Creams Containing Palm Kernel Oil and High-Oleic Sunflower Oil”
Authors: K.K. Sung, H.D. Goff