Color Quality of Blackcurrant Syrups During Storage Evaluated by Hunter L', a', b'Values


  • The author expresses appreciation to AB Findus, Bjuv, Sweden, and to The National Quality Control Authority for Processed Fruits and Vegetables, Norway, for judging and supplying samples of blackcurrant syrups of poor quality. Thanks are further due to Dr. H. Blom and Dr. E. Slinde for helpful discussions and to Ms. G. Enersen for technical assistance.


Free anthocyanin and Hunter a'value deterioration in blackcurrant syrups during storage followed fist order reaction kinetics. Half-life of Hunter a'values were 3-4 times higher than half-life values of free anthocyanins. Syrups from various cultivars. differed in color stability. Degassing of syrups prior to storage did not enhance color stability. Day-light storage of syrups lowered half-life of Hunter a'values by 10-30% compared with dark storage. Storage in oxygen permeable packaging materials reduced Hunter a'half-life values up to 90%. Hue values should be used rather than absorbance ratios A502A420 to judge color quality. Hunter a'values should be above 50 and hue values below 40–45' to ascertain acceptable color.