Method and system for determining free fatty acid content

Abstract

The free fatty acid content of an edible oil is measured by a system including a supply of a carrier solution containing an organic solvent for dissolving the oil and a color indicating reagent and an oil sample supply connected to a flow-through colorimetric detector via a sample injection valve. The sample injection valve is movable between a load position wherein a sample stream of the oil is routed to a sample waste collector via a sample loop and a stream of the carrier solution passes through the detector via a carrier solution conduit and a measure position wherein a slug of the oil in the sample loop is introduced into the carrier solution conduit and mixed with the carrier solution prior to passing through the detector. The free fatty acid in the oil reacts with the color indicating reagent in the carrier solution to produce a color of an intensity indicative of the free fatty acid content which is measured by the detector. The system also includes a selector valve manifold including up to three different calibration solutions which can be selectively introduced.