The purpose of this research is to use copper nanoparticles to monitor the quality of packaged whole and ground beef red meat. These nanoparticles are identifiers that have the ability to change color due to the production of sulphide gases during the spoilage of red beef meat. In the first step, cellulose papers impregnated with copper nanoparticles were prepared. After that, characteristics such as moisture absorption, chemical structure, stability over time, color changes of the indicator against pH changes, color changes against different volatile compounds, color changes against different concentrations of hydrogen sulfide, and color changes due to tearing. The packaging was eva‎luated. In the next step, the color changes of the identifiers were eva‎luated visually and using a colorimeter during the storage of whole and minced veal meat in the refrigerator (4 degrees Celsius) for 8 and 7 days, respectively. In order to eva‎luate the efficiency of the detector prepared for monitoring red meat of veal, the quality characteristics of red meat such as total microbial count, pH and volatile nitrogen compounds were eva‎luated during the storage of red meat of veal. The results obtained from the eva‎luation of the detectors showed that the paper detector impregnated with copper nanoparticles has a very good stability against pH changes. Also, the copper nanoparticle detector had lower moisture absorption than the control paper. Paper detector containing copper nanoparticles had high selectivity to sulfide compounds compared to volatile nitrogen compounds produced during red meat spoilage. The results obtained from FTIR showed that the copper nanoparticles were well fixed on the cellulose filter paper. The results obtained from the stability test over time showed that the color parameters of the nanoparticle paper detector had no significant color changes during storage for 30 days. The results obtained from the changes in the prepared color detector that were used during the storage of the red meat of the calf showed that the color parameters of the paper detector containing copper nanoparticles changed significantly in such a way that the lightness (L*) decreased and the red parameters - Green (a*) and yellow-blue (b*) increased. Finally, paper detectors containing copper nanoparticles showed noticeable color changes from white to reddish orange due to the reaction of copper nanoparticles with sulphide gases, which can well inform consumers of the freshness or spoilage of red meat. The results obtained from the XPS test for the color-changed detector showed that after the color change of the prepared detector, Cu2S and CuS compounds were produced, which was due to the reaction of copper nanoparticles and sulphide gases. The data obtained from the color parameters of the paper detector containing copper nanoparticles after damage to the packaging showed that not only the color of the paper detector containing copper nanoparticles did not return to its original state, but it still continued its reactivity and color changes. According to the results obtained from the qualitative performance of the paper detector containing copper nanoparticles, this detector provides a promising approach in the intelligent packaging systems of meat products to monitor the freshness of red veal meat.

هاجر شكرچي زاده

مهدي كديور

نفيسه سلطاني زاده , اميرحسين مهدوي