Production of a Functional Fresh Cheese Enriched with the Probiotic Strain Lb. Plantarum T571 Isolated From Traditional Greek Product

Olga S. Papadopoulou and Nikos G. Chorianopoulos

Institute of Technology of Agricultural Products, Hellenic Agricultural Organization DEMETER, 1 S. Venizelou Str, Lykovrisi, Athens, 14123, Greece.

Corresponding Author Email: nchorian@nagref.gr

The aim of the study was the production of fresh cheese with enhanced quality, standardized characteristics and increased functional and nutritional value. The main idea was to produce probiotic cheese with the use of probiotic bacteria isolated from the microflora of traditional Greek products. For this reason, fresh cheese was produced according to the traditional method (control) and the probiotic strain Lb. plantarum T571 was also added as co-culture (probiotic). All samples were inoculated with L. monocytogenes (3 strains) of 3 log CFU/g initial inoculum level. Microbiological analysis occured during cheese production and until the end of the shelf life of the product stored at 4°C under vacuum packaging. pH, water activity (a_W) and titratable acidity were also monitored along with the sensory analysis of the product. The survival of probiotic and Listeria strains was assessed by Pulsed Field Gel Electrophoresis (PFGE). Results showed that on the 1^st day of manufacture the population levels of lab exceeded 8 log CFU/g for all inoculated samples. By the end of shelf life, the population levels of lab in probiotic samples were approximately 7.5 log CFU/g. However, the probiotic samples resulted to significantly higher acidity, lower pH and reduced counts of coliforms and Listeria spp. The quality characteristics of probiotic products compared with the control ones were better according to the test panel. Regarding the PFGE results, Lb. plantarum T571 strain was found in all cases at populations above 7 log CFU/g. Although further research is needed, the results of the current study were encouraging for producing a probiotic fresh cheese with high added value and increased safety levels.

functional food; fresh cheese; probiotic culture; Lb. plantarum; Listeria monocytogenes; PFGE; safety

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