512 Vol. 30, 2012, No. 6: 512–519 Czech J. Food Sci. Estimation of the Shelf-Life of Halloumi Cheese Using Survival Analysis Rabih KAMLEH 1 , Imad TOUFEILI 2 , Rola AJIB 1 , Bilal KANSO 1 and John HADDAD 3 1 Department of Environmental Health, Faculty of Health Sciences, American University of Beirut, Beirut, Lebanon; 2 Department of Nutrition and Food Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon; 3 Department of Mathematics and Statistics, Notre Dame University, Zouk Mosbeh, Lebanon Abstract Kamleh R., Toufeili I., Ajib R., Kanso B., Haddad J. (2012): Estimation of the shelf-life of Halloumi cheese using survival analysis. Czech J. Food Sci., 30: 512–519. Halloumi cheese blocks, packaged in vacuum polyamide/polyethylene laminate bags, were stored at 5, 15, and 25°C. The changes in total bacterial count, lactic acid bacteria, total anaerobic bacteria, yeasts and molds, pH, and titratable acidity were monitored during the storage. The appearance of the packaged Halloumi cheese exhibited significant correlations with the counts of the different microbial populations inhabiting the cheese. The shelf-life of the stored Halloumi cheese was determined using survival analysis and considering consumer rejection as a failure index. The nominal shelf-lives of Halloumi cheese were 79.6, 37.8, and 2.6 days when stored at 5, 15, and 25°C, respectively. The Q 10 values (shelf-life at T °C/shelf-life at T + 10°C) at 5°C and 15°C were 2.1 and 14.5, respectively. The increase in the counts of different microbial populations during storage highlights the need for adherence to good manufacturing practices and maintenance of low temperatures during the storage and distribution of the packaged Halloumi cheese. Keywords: brined cheese; microbiology; sensory; Q 10 Halloumi cheese is the traditional cheese of Cy- prus. The consumption of Halloumi has become widespread and the cheese is currently manu- factured on an industrial scale in the North East Mediterranean and the Balkans (Bintsis & Pa- pademas 2002). In addition, Halloumi is exported to the European Union and North America to meet the demands of consumers for this cheese (Papademas 2006). Halloumi is produced from bovine, caprine, and ovine milks or from a mixture of different types of milk and is consumed raw, grilled, or fried. Halloumi cheese is yellow when produced from bovine milk and white when made from ovine or caprine milks (Papademas & Robinson 1998). The quality and shelf-life of Halloumi are affected by several factors including the quality of milk and the hygienic practices during processing (Bintsis & Papademas 2002). In Cyprus, fresh Halloumi is made from pasteur- ised milk. After pasteurisation and cooling, the milk is coagulated by rennet for 30 min and the resulting coagulum is cut to 1 cm 3 cubes which are then allowed to rest for 10 min and pressed into blocks at 300 kPa. The pressed blocks are boiled in whey for 1 h, drained, cooled, and stored in whey brines (12% NaCl). Mature Halloumi cheese is pro- duced by storing the fresh cheese in the whey brine (12% NaCl) for 40 days at 15–20°C (Papademas & Robinson 1998; Papademas 2006).