Determination of proline and hydroxyproline in wheat flour by spectrophotometry and measurement of radioactivity of proline-14C and hydroxyproline-14C

Abstract

Proline and hydroxyproline are two amino acids which due to their analogous chemical structures give similar reactions and often appear together. In view of the high percentage of proline in wheat gluten we have investigated the presence of hydroxyproline in wheat flour. We have developed a method to separate the two amino acids after separation from other interfering amino acids which are present in flour. The method of separation utilizes an ion-exchange column/Dowex 50 X-8, 100–200 resin/. The separated amino acids are determined either by spectrophotometry or isotope dilution /14C/ The latter method is more rapid and more sensitive than the spectrophotometric method.