Studies on the Formation of Formaldehyde in the Bleached Shrimps with Sulfite

Abstract

The formation of formaldehyde (FA) in shrimps which were bleached with sulfite solution was investigated. 1. Approximately 300 ppm of FA was detected in shrimps when they were bleached with 4.5% sulfite solution. FA was identified by Thin layer chromatography (TLC) as the dinitrophenylhydrazone and by IR spectrometry as methylenebisdimedone. The amount of FA formed in bleached shrimps increased in proportion to the sulfite concentration. 2. The following data suggest that FA in shrimps was formed from endogeneous trimethylamine oxide (TMO) upon treatment with sulfite. When TMO in a water dialysate of shrimps was fractionated by TLC, FA was detected in the TMO fraction on treatment with sulfite. When sulfite solution was added stepwise to the water dialysate of shrimps, the amount of FA formed increased with the amount of sulfite added, and the amount of TMO in the dialysate decreased correspondingly. © 1980, Japanese Society for Food Hygiene and Safety. All rights reserved.