Freshness indicator natural and artificial dyes used in atmospheric and modified atmosphere packaging of different meat samples

In this study, we are aimed to develop various pH-sensitive indicator labels prepared by adsorbing onto Whatman filter paper (no:1) using natural (pomegranate juice, red cabbage extract, turnip juice) and synthetic dyes (bromocresol green and methyl red solution) that both could attract the attention of consumers to the freshness of the packaged meat samples (beef mince, chicken breast, and trout fillet), and could be compare the expiration date written on the product samples. The meat samples packaged with air oxygen were stored for 10 days at 4ºC, while the packaged meat samples under modified atmosphere packaging (for beef mince: %70 O2, %20 CO2, and %10 N2; for chicken breast and trout fillet: %30 CO2 and %70 N2) were stored for 20 days at refrigerated storage, and the physicochemical (pH, instrumental color value, aw, lipid and protein oxidation, TVB-N content and volatile aromatic compounds), and microbiological (total psychrophilic aerobic, total coliform and total mold-yeast viable count) properties in the packaged meat samples were carried out during storage periods. Moreover, the color changes that occurred in the indicator labels were recorded simultaneously using a smart mobile phone over storage time. Throughout storage, significant increases were observed in pH value and total microorganisms (total psychrophilic, total coliform and total yeast-mold) of the both air oxygen and modified atmosphere packaged meat samples (P<0,05), and the indicator labels were exhibited important color changes depending on pH value and microbiological activity. During the storage periods, while the redness (a*) values of the all samples were statistically decreased (P<0,05), the TBARS value, carbonyl content and yellowness (b*) values of the all samples were significantly increased (P<0,05).