Abstract:

In this work, we examined the effects of storage temperature, soluble solid content (SSC) and added antioxidant
(ascorbic acid) on the chemical stability, degradation kinetics and color change of anthocyanins in blackcurrant juice. Results
showed that blackcurrant anthocyanins were stable at 4 ℃ and an SSC of 9°Brix. With an increase in storage temperature
and SSC, the level of residual anthocyanins was decreased. The degradation of anthocyanins during storage followed a firstorder
reaction. The higher the reaction rate constant k, the smaller the half-life t1/2, and the lower the activation energy Ea.
Addition of 50 mg/L ascorbic acid resulted in a significant increase in the degradation rate constant k of blackcurrant juice
anthocyanins and a significant reduction in the half-life t1/2 and the thermal degradation activation energy Ea. Therefore,
adding ascorbic acid had a positive on the reduction of residual anthocyanins. As the storage period progressed, the content
of anthocyanins in blackcurrant juice declined, and significant browning was observed in the juice together with a reduction
in brightness and redness and an increase in yellowness. In addition, ascorbic acid could promote the color change of
anthocyanins during storage.

Key words: blackcurrant juice, anthocyanins, chemical stability, color change, reaction kinetics