pH-metric determination of acid values in oilseeds without titration

A new pH-metric method for determination of acid values in oilseeds without titration has been developed in the range 0.6-10 and more mg KOH/g. The me thod is based on a rapid (1-2 min) selective and complete extraction of fre e fatty acids from an oilseed test portion into a special reagent A, separa tion of the solution from the solid oilseed material by centrifugation or f iltration, transfer of an aliquot of the solution into a pH-metric cell wit h reagent B for measurement of conditional pH(1)' of the formed mixture, ad dition of standard acid (HCl or H2SO4) and pH(2)(') measurement. The reagen ts are non-toxic, and the method is rapid. Its metrological parameters for Soybean, Canola and Sunflower oilseeds are satisfactory for practical purpo ses. (C) 1999 Elsevier Science B.V. All rights reserved.