The influence of growing season on the determination of protein in hard red spring wheat by the biuret reaction

Abstract

AbstractProtein was determined by a biuret procedure in three series of Hard Red Spring wheat samples, two of which represented different growing seasons, the third being drawn from randomised railcar lots. When calibrations were based on samples drawn from single individual seasons, differences in calibration slopes caused significant errors in the prediction of protein in samples drawn from different seasons. The analysis of the randomised lots of wheat using calibrations based on single individual seasons gave errors which were intermediate between those obtained for samples from individual seasons. However, these were closer to the results obtained using the calibration prepared from samples of the season, the wheat from which the randomised lots were mainly composed. The precision of the biuret test for all three series was superior to that of the Kjeldahl test.