ANALYSIS OF DIMETHYLPOLYSILOXANE IN TOFU BY FTIR

A simple and rapid determination method was developed for dimethylpoly siloxane (DMPS) in Tofu by FTIR. DMPS was extracted from Tofu with die thyl ether. The extract was cleaned up with a charcoal-alumina-celite column. The eluate was evaporated, and the residue was dissolved in 1 mt of n-hexane. An aliquot of the solution (100 mu L) was spotted on p olyethylene film and measured by FTIR. The absorbance was determined a t 1,260 cm(-1). The recoveries of DMPS added to Tofu at the level of 2 .5 similar to 100 mu g/g were 94 similar to 98%. The determination lim it of DMPS was 0.2 mu g/g. DMPS contents of commercial Tofu were in th e range of 0.32 similar to 73.7 mu g/g. In our test, 30 similar to 50% of DMPS added to ground soybeans was transferred into the soybean mil k in the process of making Tofu.