ACTA Scientiarum Polonorum

Abstract: Free amino acid contents: aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, valine, methionine, isoleucine, leucine, tyrosine, γ-aminobutyric acid, histidine, lysine and arginine in juices of three strawberry varieties (‘Senga’, ‘Ducat’, ‘Marmolada’), raspberry (‘Beskid’, ‘Canby’, ‘Malling Seedling’), black currant (‘Ben Lomond’, ‘Titania’, ‘Ojebyn’) and red currant (‘Rondom’, ‘Jonker’, ‘Holenderska’) were determined in this paper. Examinations were performed in three following years: 1998, 1999 and 2000, by use of HPLC method. Achieved amino acid contents were compared with standard values contained in Code of Practice. Significantly higher aspartic acid and glutamic acid concentrations of standard values published in Code of Practice were found in examined strawberry and black currant juices. Selected amino acids can be used for estimation of berry juices authenticity. Serine, valine and methionine can be the indicator of addition of strawberry juice to raspberry juice, aspartic acid and serine – addition of red currant juice to raspberry juice and aspartic acid and methionine – addition of strawberry juice to black currant juice. Adulteration of black currant juice with red currant juice cannot be detected on the base of amino acid contents.