The presence of the D- form of aspartic acid was detected in collagen of dentin and the interver- tebral disk before and assessment of its racemization coefficient was used for assessment of the age of subjects. Another tissue formed almost solely by collagen type I are tendons. Tendon tissue was not investigated so far with regard to the racemization coefficient and therefore the authors assessed the D-form of aspartic acid in the Achilles tendon. They used lyophilized tendon excisi- ons which were hydrolyzed. Amino acids in the hydrolysate were derived to N-TFA isopropyl esters which were assessed by gas chromatography on a chiral capillary column. In all samples the D-form of aspartic acid was detected. The values of the racemization coefficient suggest the possible use of thus processed tissue with certain limitations.

        Key words: assessment of age - Achilles tendon - aspartic acid - racemization