The aim of this research was to use copper nano particles and natural dyes curcumin to monitor the quality of packaged fish meat through color changing indicators. In the first stage, cellulose papers impregnated with curcumin and copper nano particles were prepared. Then, properties such as moisture absorption, chemical structure, color stability, color response to pH, specific concentrations of different volatile compounds and different concentrations of hydrogen sulfide were eva‎luated. In the next step, the color changes of the indicators were eva‎luated using hunter lab during storage of fish samples at room temperature (for 60 hours) and in the refrigerator (for 12 days). In order to eva‎luate performance of paper indicators for monitoring the quality of fish, the quality characteristics of fish such as total viable count, pH, TVB-N and volatile compounds released during storage of fish were eva‎luated using GC-MS. The results of the eva‎luation of the indicators showed that the indicator based on nanoparticle had excellent stability against pH changes. While the curcumin indicator showed significant color changes from light yellow to red-orange with increasing pH values. Copper nanoparticles had unique properties. First, the colorimetric indicator based on copper nanoparticle had a much lower moisture absorption (approximately 7.5 times) than colorimetric indicator based on curcumin. Second, the copper nanoparticle indicator has a high selectivity to sulfide compounds compared to other volatile components released by fish during spoilage. The results of FTIR indicated that copper and curcumin nanoparticles were successfully immobilized into cellulose filter paper. The results of color stability indicated that no significant changes were observed at room temperature during storage for 30 days. The results of color changes of the indicators with a similar trend during fish storage indicated that with increasing the storage time, the brightness (L *) of the indicators based on curcumin and copper nano particles significantly decreased and red-green (a *) and yellow - Blue (b *) parameters increased. Colorimetric indicator based on copper nanoparticle indicated significant color changes from white to brown by direct detection of hydrogen sulfide compounds released during fish spoilage. Colorimetric indicator based on curcumin indicated significant color changes from yellow to orange by detection of pH and TVB-N compounds released during fish spoilage. According to the results obtained from the qualitative characteristics of fish in relation to eva‎luation performance colorimetric paper indicator during fish spoilage, it can be concluded that copper nanoparticles and curcumin as the colorimetric indicator provides a promising approach in intelligent packaging systems for meat products to monitor fish meat freshness in real time

هاجر شكرچي زاده

نفيسه سلطاني زاده

مهدي كديور، مهرنوش جعفري