Research Note: A New Technique for Reddening Florets: UV-Light Irradiation on Saffron Thistle (Carthamus tinctorius L.) Flowers

Juices of six sea buckthorn (Hippophae rhamnoides L., tyrni in Finnish; Sanddorn in German) elite genotypes, representing different origins or hybrids, were evaluated for concentrations of chemical constituents, sensory attributes, and overall pleasantness with or without addition of sugar. The sugar (glucose+fructose) concentrations ranged from 0.37 to 4.58 g per 100 g berries, while titratable acidity as citric acid varied from 2.36 to 4.66 g per 100 g berries. The juices were characterized by astringency, sourness and bitterness. These three attributes were highly intercorrelated and differed significantly among samples. Subjects preferred a red colour, but colour and intensity of aroma only weakly affected pleasantness ratings. Sweetness had strong positive effects on juice pleasantness. Sweetening with 6.5% of sucrose improved juice pleasantness markedly. Hybrids were generally rated more pleasant than non-hybrid samples. Hybrid Fin×Sib (subspecies rhamnoides×subspecies mongolica) gave the most acceptable juice. Of all chemical data, titratable acidity was significantly correlated with the intensities of astringency, sourness and, negatively, with sweetness. Sugar:acid ratio was better associated with juice pleasantness than sugar alone.