title: Re-evaluation of selectivity of malachite green test for presence of sulfite in mechanically deboned poultry.
abstract: A study was undertaken to determine whether free chlorine or sulfide anions could yield positive results for the malachite green test in meat samples when sulfite was not present. Malachite green solution was added to a mechanically deboned poultry (MDP) sample spiked with either chlorine or sulfide ions. The presence of chlorine in MDP samples at any concentration tested did not yield a positive reaction for the malachite green test. When sulfide ions were introduced into MDP samples, positive results were observed at 40 micrograms sulfide ion/g MDP and above. Because aqueous solutions of sulfide at the levels mentioned have a relatively high pH, it was necessary to determine whether the pH or the presence of the sulfide ions had caused this positive reaction to the malachite green test. After a comparison of a solution of sulfide, and a solution of a matching pH, it was observed that the sulfide present caused the positive reaction to the malachite green test.
mesh_terms: D000818:Animals; D005506:Food Contamination / Q000032:analysis*; D005511:Food Handling; D011202:Poultry Products / Q000032:analysis*; D012394:Rosaniline Dyes; D013447:Sulfites / Q000032:analysis*
chemical_list: D012394:Rosaniline Dyes; D013447:Sulfites; C005095:malachite green