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Determination of the total tryptophan in food by high performance liquid chromatography combined with enzyme hydrolysis

Published 04/10/2019

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How to Cite
Luu Thi Huyen Trang, Vu Thi Trang, Le Viet Ngan. "Determination of the total tryptophan in food by high performance liquid chromatography combined with enzyme hydrolysis". Vietnam Journal of Food Control. vol. 2, no. 2 (en), pp. 37-43, 2019

Main Article Content


High performance liquid chromatography was applied for the determination of tryptophan in food. The sample was hydrolyzed in a duration from 16 to 24 hour by protease enzyme at 50 oC. The extract was separated on the C8 reversed phase column with mobile phase of NaH2PO4 50mM pH 2.3: Methanol (82:18; v/v). The linearity of the method was kept in the range of 0.5 - 50 mg/L. Limit of detection was found to be 4.6 mg/100g. Recovery was determined by standard addition method, giving values of recovery in the range of 97 - 103% and RSD (n = 6) in the range of 0.077 - 2.27%. Internal standard was used to reduce the errors in analysis process and good reproducibility.


HPLC, Tryptophan, food, amino acid


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