Reverse-phase high performance liquid chromatography technique was used for studying the evolution of bitter acids from three varieties of hop growing in Romania during the development of hop cones and the pelletisation process in order to provide the information on the bitter acids profile of each cultivar. Chemometrics methods were applied for highlighting the statistical correlations existing between the genotype (variety), chemotype (composition), and phenotype (phenophase of cone development) with respect to the classes of biologically active compounds investigated (bitter acids). The bitter acid content of each hop cultivar was not only significantly dependent on the phenophases of the cones, but was also influenced by the harvest year. The variations in the α/β ratio as well as cohumulone and colupulone contents were low in both experimental years and the cohumulone/∑α did fraction not exceed 30% in any of the three varieties.
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