AGE ESTIMATION OF OLD CARPETS BASED ON CYSTINE AND CYSTEIC ACID CONTENT

A method for the evaluation of the age of wool carpets and textiles wa s developed based on the age dependent alteration of amino acid compos ition of proteins. Samples of 23 wool carpets and textiles of known ag e, obtained from the Hungarian Museum of Industrial Arts and the Hunga rian National Museum were analysed for amino acid content. Results wer e compared with: data obtained for contemporary, untreated wool and wo ol carpet. The cysteic acid content of wool increases with age. The co ntemporary wool carpet contained 0.31 g of cysteic acid in 100 g of pr otein. Comparable figures were 1.87 g for a 550-year old carpet and 4. 01-4.39 g for the 1600-1750 year old wool carpets. The cystine content decreased with age, the corresponding figures being 7.88, 3.12 and 1. 19-0.97 g/100 g, respectively. Corresponding contents of methionine we re 0.43, 0.21 and 0.20-0.00 g/100 g and for tyrosine 3.07, 2.11 and 0. 20-0.00 g/100 g. Prediction equations were developed as linear regress ions of the age of wool on cysteic acid, cystine and tyrosine contents . The 95% confidence intervals of estimates for two samples of unknown age were estimates plus or minus 30 and 38 years.