IDENTIFICATION OF COW MILK ALLERGEN IN THE PRODUCTS OF GRAPE PROCESSING

Abstract

The aim of research was the identification of cow milk allergen in grapes, must, federweisser and wine by immunochemical method ELISA. Milk allergens (casein) are mostly used together with egg proteins during wine clarification. The results show that quality of calibration curves has significant importance for objective evaluation of quality detection. The degree of the variability calibration samples expressed R2 was not less than 0.9 in both calibration curves (0.9485 and 0.9659). In grape samples, concentrations of cow's milk casein below the detection limit were determined, that is recommended by the ELISA kit manufacturer. All grape samples showed casein concentration less than the value corresponding to 0 ppm standard (from 0.039 to 0.127 mg/kg). Low concentrations were recorded in three samples of must (from 0.056 to 0.077 mg/kg) as well. In case of the federweisser, the casein concentration ranged from 0.367 to 1.301 mg/kg, which is still less than 1.5 ppm standard (1.373 mg/kg). Most of the wines were found to be in the ELISA detection range. The exceptions were samples no. 3 and 9, whose absorbance was above the highest standard (45 mg/kg). These samples were then reconsidered after the first dilution, the resulting cow milk casein concentration was 67.22 mg/kg and 48.66 mg/L. Higher concentrations of this protein contained white wines (from 21.473 to 67.22 mg/L). In red wines, the milk protein concentrations ranged from 1.634 to 16.715 mg/L.