The research, published in the journal Innovative Food Science and Emerging Technologies, taps into a growing trend looking at natural alternatives to synthetic additives that could have significant implications for food formulators.
"The results obtained demonstrated that the addition of polyphenolic co-pigments extracted from distilled rose petals reduced the thermal degradation of strawberry anthocyanins, allowing improved colour stability of the processed strawberries," wrote lead researcher Plamen Mollov from the University of Food Technologies in Bulgaria.
"This implies that fruit processing technology should orient itself in accordance with nature's patterns, especially since more and more consumers reject the application of synthetic additives."
Mollov and co-workers looked at the effect of using polyphenolic co-pigments extracted from rose petals (Rosa damascena Mill.) on the colour of strawberry pigments in a beverage that underwent a heat treatment.
The rose petal polyphenols were added to the strawberry beverage at a one to five ratio of total anthocyanins, with a total pigment concentration of approximately 0.0001 moles.
Addition of the rose petal polyphenols increased the colour stability of the beverage, particularly after prolonged heating (four hours), said the researchers.
"This polyphenolic fortification could be worthwhile not only from a technological point of view, but also with respect to the development of functional foods and beverages," they said.
Confronted by growing consumer demand for natural and healthy foodstuffs, food makers have increasingly been looking for alternatives to artificial food colours such as Sunset Yellow, Tartrazine and Quinoline Yellow.
Market figures confirm the trend. While the European colouring market faces an annual growth rate of just 1 per cent between 2001 and 2008, the colouring foodstuffs market is ripping ahead on growth of 10 per cent to 15 per cent.
Source: Innovative Food Science and Emerging Technologies (Elsevier)
Published on-line ahead of print, doi: 10.1016/j.ifset.2007.03.004
"Colour stability improvement of strawberry beverage by fortification with polyphenolic co-pigments naturally occurring in rose petals"
Authors: P. Mollov, K. Mihalev, V. Shikov, N. Yoncheva and V. Karagyozov