Rapid ecologically acceptable method for wheat protein content determination - Comparison of methods

To display features of the rapid and simple automatic Dumas method for nitr ogen determination in wheat flour the method was compared with the standard Kjeldahl method as a referential one. The method is based on full incineration of sample and on total nitrogen de termination in relation to the thermal conductivity of the nitrogen-helium mixture. Method testing proceeded by comparing the level of nitrogen in whe at flour samples determined by both methods. Data analysis of the protein c ontent of the samples as determined by these two methods showed a significa nt positive correlation (r = 0.975). An assessment of the two methods' prec ision revealed that standard errors of the averages of parallel determinati ons were not essentially different, i.e., the results yielded by Dumas' met hod and standard Kjeldahl's method were the same. This rapid, simple and re adily performed method permits doing many tests daily, using up a small amo unt of the sample (0.1-1g) and dispensing with the use of noxious chemicals . It can thus be recommended as a very simple method to use and constitutin g an ecologically acceptable replacement for the standard Kjeldahl's method .