Article ID Journal Published Year Pages File Type
1190864 Food Chemistry 2007 10 Pages PDF
Abstract

The effect of pH and temperature on the stability and visual colour of aqueous anthocyanin (ACY) extracts from purple- and red-flesh potatoes was evaluated and compared to commercial ACY extracts from grape and purple carrot. Extracts from purple carrot and red-flesh potatoes showed higher stability than grape and purple-flesh potato extracts. Stability to pH (⩽3) and thermal degradation of extracts (pH 3) followed first-order kinetics. Changes in lightness and hue followed zero-order kinetics, while changes in chroma followed first-order kinetics. Degradation parameters such as t1/2, k-, D-, z- and Q10-values were determined. Extracts from red- and purple-flesh potatoes at pH 3 showed similar hues to FD&C Red #40 and red cabbage extracts, respectively. The visual colour of both potato ACY extracts was also affected by tinctorial strength. The use of purple- and red-flesh potatoes as a source of natural colorants shows potential use in the pH region around 3.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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