Comparison of three methods for capturing sulfites in shrimp treated with sodium metabisulfite

Abstract

The aquaculture industry in southern aims to increase the marketing of whole shrimp in North American and European markets, strongly punishing shrimp with melanosis or higher sulfite residues 100 ppm, respectively.

Septoria involves developing a black discoloration in the exoskeleton of shrimp. Sodium metabisulfite (MBS) inhibits the formation of melanosis.

For residues of sulfites in shrimp treated with MBS tapes employ colorimetric methods, titration and titration iodometrically Monier-Williams (MW).

The objectives of the study were to evaluate methods to detect sulfites in shrimp treated with MBS and determine the amount of sulfites detected with the procedure MW at different times distillation.

Were selected from a pond shrimp production as texture features of the exoskeleton who underwent 0.5 % baths and 1.0 % of MBS. The concentrations of sulfites and melanosis development for eight weeks of storage at -18°C.

The tape method is not accurate colorimetric detection sulfites shrimp the MW method that sulfites detected more iodometrically (P <0.004). Highly significant correlations were found with MW between sulfites method detected after each distillation time (P <0.001). MBS shrimp treated with sulfites showed reduced along eight weeks of storage (P <0.04).

MW method was shown to be more accurate in the detection of sulfites. According to the test results can shorten the time of distillate in the method for detecting MW sulfite waste properly in shrimp. The MBS-treated shrimp melanosis had fewer (P <0.02) than untreated freezing for eight weeks.

DOI: http://dx.doi.org/10.5377/rct.v0i14.1796

Revista Ciencia y Tecnología No. 14, junio 2014: 62-76