Simultaneous detection of melamine and urea in gluten with a handheld NIR scanner

The standard analytical methods for the determination of total protein content, which is an important measure of quality in many food products, can be easily miss leaded by adding nitrogen deriving from different source driving to serious adulteration of the various foods. Therefore, there is an immense need to develop rapid method to detect multiple adulterations with handheld instruments. The objective of the present work is to develop multivariate models for simultaneous prediction of melamine and urea in wheat gluten samples with a handheld NIR scanner. Wheat gluten samples from ten different manufacturers from different part of the world were mixed with melamine and urea in different ratios to provide a robust enough sample set for spectral data acquisition. In spite of the natural separation based on the geographical origin of the gluten samples it was possible to build accurate models for simultaneous quantification of common food adulterants, melamine and urea, in multiple mixtures of gluten. The results show Tellspec Enterprise Food Sensor as a rapid, cost effective and user friendly tool can be used for the determination of melamine and urea adulteration in wheat gluten down to 1 % concentration.