Relationships between colour parameters, phenolic content and sensory changes of processed blueberry, elderberry and blackcurrant commercial juices

摘要

There is an increased interest in the consumption of fruits containing high phenolic concentrations such as berry fruits. Attractive colour of berries plays a vital role for consumer acceptance. The aim of this work was to evaluate colour parameters (a~*, b~*, L~*), phenolic content and sensory changes of blueberry, elderberry and blackcurrant (BC) pasteurised commercial juices during accelerate storage. Initial phenolic concentration was 3.21, 10.06, 10.72 g GAE L~' for blueberry, elderberry and BC, respectively. Moreover, phenolic concentration of all juices decreased by approximately 40% throughout the first 30 days. Blueberry exhibited a substantial decrease in a~* (40%) in the first 30 days, while elderberry presented a gradual decrease and BC only presented a slight decrease (7%) at the end of storage. Colour preferences decreased when storage time increased. However, when consumers were informed that 'the juices are a rich source of phenolics, which contribute to reducing risk of suffering chronic diseases', a high level of purchase intention was obtained.