Amido black dye binding of alfalfa and forage legume protein

Although dye binding has been suggested for the determination of alfalfa protein content, a standard method has not been advanced. More data are necessary on the conditions required for the dye-protein reaction. Reaction times of 8, 12 and 24 hours and reaction temperatures of 50, 55, 60 and 65 degrees C were selected to obtain dye binding values (DBV) with the Foss Pro-Milk apparatus. A correlation of 0.88 with macro-Kjeldahl values was obtained. 60 degrees C and 24 hours reaction time can be considered conditions yielding maximum DBV. It is suggested to develop a standard method for the routine measurement of forage legume content.