[The dot-blot technic for quantitative determination of wheat protein in sausage]

A simple immunological method is described by which it is possible to detect the wheat flour according to wheat protein in the heat-processed meat products. The wheat proteins were extracted with a buffer TRIS-NaCl (0.02 mol/l, 0.5 mol/l) from: a) wheat flour; b) model meat products with addition of wheat flour (3.2, 3.2, 3.6, 0.8, 0.4 and 0.2%); c) commercial meat products containing wheat flour (sausages-S, P, PF). The aliquots of the extracts were subjected to an immunological dot-blot test. The extracts from the wheat flour and the model meat products were used for calibration of this method. The quantitative evaluation of the test was based on the spectrophotometric determination of the quantity of the violet stain on the nitrocellulose (NC) strip surfaces. The strips were immersed into the acetone and the absorbance were determined at 580 nm. The screening of the samples by dot-blot procedure proved to be an efficient way of the wheat flour determination in the cooked meat products at 0.2% level (i.e. 0.375 ng of wheat protein applied to the NC strip). Since the wheat antibody (primary antiserum) has no crossreactivity with pork or beef, this technique can be used for the detection of plant proteins in the mentioned mixtures.