A new organic phase bienzymatic electrode for lecithin analysis in food products

The aim of the present research was to examine the possibility of constructing a bienzymatic sensor for lecithin determination, which must be capable of operating in organic solvents, in which lecithin is more readily soluble, as well as to evaluate the possibility of applying it to the analysis of food matrices. The new OPEE (organic phase enzyme electrode) was obtained by using as electrochemical transducer a gas diffusion amperometric electrode for oxygen while the enzymes (phospholipase D and choline oxidase) were both immobilised either in a dialysis membrane or in kappa-Carrageenan gel. This biosensor was used to study the possibility of determining lecithin content in several food samples (egg yolk, soya flour and oil, etc.) as well as in some diet integrators, operating in a chloroform-hexane (1 + 1 by volume), or chloroform-hexane-methanol (1 + 1 + 0.02 by volume) mixture. (C) 1998 Elsevier Science S.A. All rights reserved.