Rapid detection of the freshness of grass carp (Ctenopharygodon idella) fillets by colloidal gold immunochromatography assay

Consumers are greatly concerned about fish freshness. Therefore, this study was aimed to provide a colloidal gold immunochromatography assay (GICA) system for rapid detection of fish freshness. A suitable fish protein was chosen as an antigen for GICA; and the properties and effectiveness of the GICA system were investigated. Results showed that parvalbumin (PV) was suitable as a fish freshness indicator, proven by hierarchical cluster analysis and chosen as a GICA antigen. The GICA system revealed high specificity in the 27-212 mu g/L detection range. The correlation coefficient R2 towards enzyme-linked immunosorbent assay reflected high reliability as 0.998. The GICA system was stable within 12 weeks at room temperature. The fitness for indicating freshness by GICA ranged from 87.27% to 111.72%. In short, the GICA system with PV as an antigen could be used as a simple, rapid, and accurate technique for the freshness detection of grass carp fillets.