STABILITY OF CONCORD GRAPE (V. labrusca) ANTHOCYANINS IN MODEL SYSTEMS

Abstract

ABSTRACT An anthocyanin extract was prepared by treating Concord grape filter trim with methanol acidified with 0.01% citric acid. The extract was concentrated to provide an aqueous extract for testing as a colorant for beverages. The concentrate was freeze‐dried on a dextran carrier for use with a dry beverage mix. The stability of the anthocyanins in beverages with added glucose or sucrose was not pH dependent over the range from pH 2.8—3.6. Presence of ascorbic acid increased the pigment degradation rate. 5‐hydroxymethyl‐Zfurfural (HMF) did not accumulate on storage in sufficient amounts to affect appreciably the degradation rate. D 2 1 2 and z values were determined under aerobic conditions for several systems. The calorimetric “a/” L' function correlated well with anthocyanin content at higher storage temperatures. The pigment was very stable in carbonated beverages, jelly and dry beverage base mix.