Shelf life of Turkish whey cheese (Lor) under modified atmosphere packaging

Abstract

In this study, the shelf life of Lor cheese stored under different atmosphere compositions was assessed and compared. Lor cheeses were held in four different atmospheres containing: vacuum packaging (VP), 40% CO2/60% N-2, 60% CO2/40% N-2 and 70% CO2/30% N-2 (modified atmosphere packaging). Control cheeses were stored in air. All cheese samples were kept in the refrigerator at 4 degrees C for 45 days and investigated for physicochemical, microbiological and sensory properties. The acidity index value was significantly higher (P < 0.05) in the control and vacuum packaged samples than in those stored for the same period under CO2. Microbiological results showed that modified atmosphere packaging delayed microbial growth compared with air and VP samples. Of the three modified atmospheres, gas mixtures 60% and 70% CO2 were the most effective for inhibition of growth of micro-organisms. Sensory evaluation (odour and taste) results showed that Lor cheese packaged under modified atmosphere packaging (60% CO2/40% N-2 and 70% CO2/30% N-2) retained good characteristics for 45 days of storage, while vacuum and control samples were sensorily unacceptable after 10 days of storage.