The rare sugar D-psicose may be an ideal substitute for sucrose, and have the added benefits of boosting antioxidant activity and boosting shelf-life, say Japanese researchers.
D-psicose is a non-calorie sugar with a reported lower glycemic response. It has 70 per cent the sweetness of sucrose, but also has functional properties like gelling activity, good flavour, as well as high antioxidation activity.
The sugar is not exploited to any great extent in the food industry, but research published in the Journal of Agricultural and Food Chemistry indicates the potential of the sugar to find application in a range of products, most notably as a sucrose substitute.
"The excessive consumption of sucrose can be ill-advised because of the high calorie content and a high glycemic response," wrote lead author Yuanxia Sun from Kagawa University.
"On the other hand, artificial intense sweeteners (such as aspartame, sucralose, saccharin, and cyclamate) are almost calorie-free, but their function is only to sweeten and inherently lack the bulk of sucrose.
"Food formulators generally need to blend them with sugar to obtain successful end products. Hence, sucrose cannot be substituted by only intense sweeteners."
But the research indicates that D-psicose may be an effective substitute.
The Japanese researchers investigated the effects of D-psicose on the foaming properties of egg white protein and the quality of butter cookies.
According to the results, the foaming of the egg white protein was improved by the addition of D-psicose at a 15 per cent of sugar content. Under a longer whipping time, the researchers report that the D-psicose-egg white solution was "better in foaming capacity compared to sucrose- and fructose-egg white solutions."
"The results did not show a clear mechanism by which addition of psicose induced the high foaming property of egg white protein, but confirmed that the addition of psicose was much more effective than the addition of sucrose, especially in the case of a longer whipping," they wrote.
For the cookies, the rare sugar was used as a partial sucrose replacer. No significant changes in cookie quality were reported.
"Conversely, it dramatically increased antioxidant substances produced through the Maillard reaction during heat processing," added Sun. "The antiradical activity and reducing power of the cookies are strongly related to the colour change of the cookie crust.
"Thus, D-psicose could be used as a sweetener to develop a functional food with a high antioxidant activity and a low calorie content by controlling the colour change of the final products," they concluded.
According to market researcher Freedonia, overall sweetener prices are forecast to see erosion, following an increased dynamism in the sweetener industry, which is currently seeing a number of new options available after years of relative stability.
Source: Journal of Agricultural and Food Chemistry
Published online ahead of print, ASAP Article, doi:10.1021/jf800050d
"Influence of a Rare Sugar, D-Psicose, on the Physicochemical and Functional Properties of an Aerated Food System Containing Egg Albumen"
Authors: Y. Sun, S. Hayakawa, M. Ogawa, K. Fukada, K. Izumori