Standardization of the Ammonia Electrode Method for Evaluating Seafood Quality by Correlation to Sensory Analysis

Abstract

ABSTRACT: Ammonia ion‐selective electrode (ISE) measurements, reported as apparent ammonia, were correlated to expert sensory assessments of 6 different fish species stored on ice and at room temperature. Total volatile base nitrogen (TVB‐N), trimethylamine nitrogen (TMA‐N), and apparent ammonia showed the same development trend during storage. ISE measurements and TVB concentrations had a correlation of r 2 = 0.92. Sensory assessment, using a 1‐ to 100‐mm line scale with values > 50 considered unacceptable, resulted in an r 2 between sensory scores and ISE measurements of 0.78. Regression analysis predicted 19.6 mg/100 g of apparent ammonia in fish tissue at the sensory limit of 50, regardless of storage conditions. ISE measurements could be used in predicting borderline quality and decomposition.