OMA Protocol Review: OMAMAN-56 Sulfites in Shrimp

BIOFISH 300 SUL: Method Range Extension

AOAC Performance Tested Method SM 031802

Abstract Background : The BIOFISH 300 SUL method was recently PTM certified by the AOAC Research Institute for the quantification of sulfite in crustaceans in the 30-300 mg/kg range. Sulfite in raw shrimp head on,

head off, and boiled shrimp was analyzed, and method performance was examined using naturally

contaminated and spiked samples, with comparison to OMA 990.28. The BIOFISH method is a highly

content. The

specific enzymatic biosensor for the rapid quantification of sulfite, measured as SO 2

method mainly consists of the extraction of sulfite from the solid matrix in an aqueous based solution

with the aid of an Ultra-turrax, and its subsequent quantification by the BIOFISH 300 biosensor in less

than 3 minutes. Objective : In order to meet regulatory needs, a new quantification range has been developed, so the quantification limit of the method has been lowered down to 7 mg/kg. Methods : Comparative studies between BIOFISH 300 SUL and OMA 990.28 were conducted for naturally

contaminated and spiked samples of raw head off shrimp and boiled shrimp with sulfite levels lower

than 30 mg/kg in order to determine accuracy, bias, repeatability, intermediate reproducibility and

recovery. Results : Overall results demonstrated linearity of response, 88-109% accuracy and 3.1-11.0% repeatability precision for the BIOFISH 300 SUL new range, with a validated LOQ of 7 mg/kg.

) ranged from 3.63% to 9.09% for incurred raw and boiled shrimp over

Intermediate reproducibility (RSD i

the range 5.75-30 mg/kg sulfite. Conclusions : This study shows that the BIOFISH 300 SUL is an alternative technique to the traditional modified Monier Williams method that, apart from being faster

and cleaner, allows the quantification of sulfite below 10 mg/kg, a critical value that should not be

exceeded without being declared in the product labeling.

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