engleski

Influence of starch addition on colour of red currant juice during heating

In this work, model solutions of red currant juice with addition of starch were investigated. It is well known that anthocyanins are quite unstable, especially at high temperature, so samples were prepared with an addition of 1 % of starch, waxy maize or tapioca, to investigate influence of starch on anthocyanin content and colour during heating of samples at 30, 50, 70 and 90 °C for 30 minutes in comparison with control sample (without starch). Addition of both starches caused higher degradation of anthocyanins during heating (27.92% and 8.76% for waxy maize and tapioca starch, respectively) in comparison with control sample (6.71%). To get a complete picture of colour of model solutions, also L*, a* and b* parameters were determined and total colour change (Δ E*) was calculated. During heating, a* values decreased for all samples. b* values of control sample didn't change significantly with heating, while in samples with addition of starch the change of this parameter was more pronounced. During heating, Δ E* was lower in control sample, from 0.14 to 0.27, while with the addition of starch Δ E* significantly increased (0.89 to 1.35), and it was more pronounced when tapioca starch was added.

starch addition; anthocyanins; colour; heating; red currant juice

nije evidentirano