Colour stability improvement of strawberry beverage by fortification with polyphenolic copigments naturally occurring in rose petals

Heat stability of strawberry anthocyanins was studied depending on the addition of polyphenolic copigments naturally occurring in rose (Rosa damascena Mill.) petals. The anthocyanin degradation ideally followed first-order reaction kinetics (R=0.99) and the half-life value increased significantly due to the addition of rose petal polyphenolics. Further, CIELCH colour coordinates of thermally treated strawberry beverage were monitored depending on the fortification with polyphenolic copigments. Colour stability increased due to the addition of rose petal polyphenolics, as the total colour difference was smaller for the fortified beverage, especially after prolonged heating (4 h). The results obtained demonstrated that the addition of polyphenolic copigments extracted from distilled rose petals reduces the thermal degradation of strawberry anthocyanins, allowing improved colour stability of the processed strawberries. Moreover, this polyphenolic fortification could be worthwhile not only from technological point of view, but also with respect to the development of functional foods and beverages. (c) 2007 Elsevier Ltd. All rights reserved.