6533b858fe1ef96bd12b5949
RESEARCH PRODUCT
Extension of Tosela cheese shelf-life using non-starter lactic acid bacteria
E. PoznanskiElena FranciosiLuca SettanniA. CavazzaPier Sandro Cocconcellisubject
Lactobacillus paracaseiFood Handlingmedicine.disease_causeMicrobiologyMicrobiologyIndustrial Microbiologychemistry.chemical_compoundbacteriocinBacteriocinListeria monocytogenesLactobacillus rhamnosusBacteriocinsCheesenon-starter lactic acid bacteriamedicineAnimalsHumansFood microbiologyLactic AcidFood scienceSettore CHIM/10 - CHIMICA DEGLI ALIMENTIbiologyShelf-lifeFood preservationStreptococcusfood and beveragesbiology.organism_classificationLactic acidLactobacillusMilkchemistryTasteFermentationFormaggi freschiCattlenon-starter lactic acid bacteria; fresh cheese; bacteriocins; shelf-lifeFresh cheeseBacteriaFood ScienceNSLABdescription
Six strains of non-starter lactic acid bacteria (NSLAB) were used to extend the shelf-life of the fresh cheese Tosèla manufactured with pasteurised cows’ milk. The acidification kinetics of three Lactobacillus paracasei, one Lactobacillus rhamnosus and two Streptococcus macedonicus were studied in synthetic milk medium. Lb. paracasei NdP78 and NdP88 and S. macedonicus NdP1 and PB14-1 showed an interesting acidifying capacity and were further characterised for growth in UHT milk and production of antimicrobial compounds. Lb. paracasei NdP78 and S. macedonicus NdP1 grew more than 2 log cycles in 6 h. Lb. paracasei NdP78 was also found to produce a bacteriocin-like inhibitory substance (BLIS) active against Listeria monocytogenes. The four NSLAB strains (singly or in combination) were used to produce experimental pilot- scale cheeses which were compared by a panel. The cheese manufactured with the mixed culture Lb. par- acasei NdP78 - S. macedonicus NdP1 was the most appreciated for its sensory properties. The cheeses produced at factory-scale showed higher concentrations of lactobacilli (7.90 log CFU/g) and streptococci (6.10 log CFU/g), but a lower development of coliforms (3.10 log CFU/g) and staphylococci (2.78 log CFU/g) than control cheese (4.86, 4.89, 4.93 and 5.00 log CFU/g of lactobacilli, streptococci, coliforms and staphy- lococci, respectively) processed without NSLAB addition. The food pathogens Salmonella spp. and Listeria monocytogenes were never detected. The dominance of the species inoculated was demonstrated by denaturing gradient gel electrophoresis (DGGE), whereas strain recognition was evaluated by randomly amplified polymorphic DNA (RAPD)-PCR. From the results obtained, Lb. paracasei NdP78 and S. macedonicus NdP1 were able to persist during the storage of Tosèla cheese and their combination influenced positively the sensory characteristics and shelf-life of the final product.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2011-01-01 |