SHELF-LIFE OF UNSALTED AND LIGHT "LOR" WHEY CHEESE STORED UNDER VARIOUS PACKAGING CONDITIONS: MICROBIOLOGICAL AND SENSORY ATTRIBUTES

The shelf life of unsalted and light Turkish whey cheese "Lor " in various packaging conditions of atmospheric air, vacuum and modified atmosphere packaging (MAP) (80%CO2/20%N-2; MAP1 and 60%CO2/40%N-2; MAP2) under refrigeration (4C) was investigated and compared with each other for a period of 25 days. MAP1 was the most effective for inhibiting growth of total viable count, yeast and mold, and Enterobacteriaceae microflora in Lor cheese samples until 20 days of refrigerated storage. Yeasts and molds were inhibited effectively under MAP2 packages as well. Vacuum-packaged samples gave a lower lactic acid bacteria count at a given sampling day than the other packages. MAP and vacuum packages were not found effective on psychrotrophic bacteria counts. Results show an increase in the shelf life of MAP packaged Lor whey cheese, confirming that inhibitory effects on some of the microorganism groups are responsible for the spoilage phenomena. Refrigeration condition with MAP combination of Lor cheese had good sensory characteristics for 20 days of storage, while control samples were unacceptable after 10-15 days of storage. PRACTICAL APPLICATIONS The modified atmosphere packaging (MAP) of foods has considerably increased recently. MAP with CO2 was found very effective on spoilage microorganisms because of its bacteriostatic effect. Generally, Lor cheese is packaged in atmospheric air or vacuum conditions in Turkey; there is no any research about the extending the shelf life of Lor cheese, and it has a very short shelf life although it is vacuum-packaged. Modified atmosphere packages of unsalted and light Lor cheese were found effective on microbial and sensory qualities of it and MAP packages could be used for Lor cheese, to give better results than vacuum packaging together with good sanitary conditions, during the packaging process.