Viability of Bifidobacterium bifidum and Its Effect on the Microbial, Chemical and Sensorial Characteristics of Traditional Koozeh Cheese

  Koozeh cheese is among the best known of all traditional Iranian cheeses. The Bifidobacteria family has been considered in functional food products due to its probiotic properties in recent years. Viability of probiotic bacteria during the maintenance and time of consuming in food has become a challenge in food hygiene and technology. The aim of this work was to investigate the viability of bifidobacterium bifidum and its effect on the microbial, chemical and sensorial characteristics of traditional Koozeh cheese Survival of Bifidobacterium bifidum (ATCC 29521) was investigated in the traditional Koozeh cheese prepared from pasteurized milk and non-pasteurized milk. B.bifidum was counted at 1, 15, 30, 45, 60, 75 and 90 days. The cheese samples were assessed for microbiological and chemical properties. Then they also were analyzed for sensory evaluation at the end of 90 days of ripening stage. The amount of Bifidobacterium bifidum in the cheeses produced by pasteurized milk and unpasteurized milk increased by as much as 2 and 1 log cycles, respectively. Moisture and pH were lower in the cheeses produced by pasteurized milk containing probiotic in compare to the the other samples. Salt content was significantly different in the samples produced by unpasteurized milk with probiotic at the end stage of cheese ripening. The sensory evaluation showed that the samples produced by pasteurized milk enriched with probiotic significantly had higher sensory scores. It was concluded that probiotic Bifidobacterium bifidum can be used successfully in Koozeh cheese without adversely affecting the cheese quality during ripening. The reduction of total viable and yeasts–molds counts was observed during the maturation of cheese samples. The Koozeh cheese matrix can be used as a proper carrier of probiotic microorganisms