Determination of Amino Acids in Wheat and Barley by Near-Infrared Reflectance Spectroscopy

Abstract

The use of NIR spectroscopy for the prediction of amino acid compositions in wheat and barley has been demonstrated. Using 2nd derivative mathematical treatments of log I/R data of ground wheat samples obtained on the Beltsville Universal Computerized Spectrophotometer, the concentration of lysine, threonine, tryptophan and methionine could be predicted with accuracies acceptable for screening purposes. With barley samples low standard errors of prediction (high accuracy) were obtained for I3 amino acids using a research NIR and a commercial bench-type instrument. For both of these instruments, use of 1st derivative mathematical treatments of spectral data gave the best accuracy. Results indicated that NIR techniques may be very useful in plant breeding programs and in the food and feed industry for the rapid and accurate analysis of amino acids.