Queijo tipo minas frescal probiótico processado por alta pressão hidrostática: aspectos microbiológicos e físico-químicos

Abstract

Probiotic bacteria are applied to cheeses in order to confer benefits to the health of the consumer and market differentiation to the product. The High Hydrostatic Pressure (HHP) has the potential to be applied in fresh cheeses, aiming inactivating potentially pathogenic or spoilage microorganisms and prolonging the shelf life. With the intention of developing a product with greater health and stability, the present work had as objectives to select probiotic bacteria and HHP process conditions possible to be applied to Minas Frescal cheese. In research and development, the production of miniature cheeses is an efficient alternative to carry out laboratory analysis, compared to the traditional process of making Minas Frescal cheese, the adaptation of this method allowed a better control of cheese preparation, making the application more effective for the experiment. The probiotic cultures used were Bifidobacterium animalis subsp. lactis BLC 1 (SACCO, Italy), Lactobacillus acidophilus LA-5 (Chr. Hansen, Denmark) and Lactobacillus ramnhosus BRM038563 (Embrapa Goats and Sheeps, Brazil). Analyzes were carried out to evaluate the effect of different combinations of pressure and time of the HHP process on the characteristics of the cheeses and on the viability of probiotic cultures throughout the refrigerated storage. Bifidobacterium subsp lactis was selected because it presented satisfactory levels of microorganism counts during the storage of the Minas Frescal cheese, besides being more viable when submitted to the HHP process than the other probiotics, without negatively affecting the physical and physicochemical characteristics of the cheese. No Salmonella sp / 25g, Staphylococcus aureus and Coliforms 45 °C were detected in the samples. After 28 days of storage, the control sample presented 4.43 log CFU/g of psychrotrophics, while those processed at 200 MPa/5 min reached a growth of 3.81 log CFU/g and at 350 MPa/5min had growth of only 1.49 log CFU/g. Regarding the survival of the probiotic microorganism, the Bifidobacterium subsp lactis count was initially 8.13 CFU/g for Control sample (non-pressurized), while samples processed at 200MPa/5min and 350MPa/5min resulted in 7.38 and 6.26 log CFU/g, respectively. Up to 28th-storage-day, there was a reduction of less than 2 Log in all treatments, reaching 6.98 log CFU/g for Control sample, 5.93 log CFU/g for 200 MPa/5 min. and 4.52 log CFU/g for 350 MPa/5min. No significant differences were observed (p> 0.05) for moisture, pH and total acidity. HHP was able to inhibit the growth of spoilage microorganisms, maintaining a relevant concentration of probiotics throughout the Minas Frescal cheese storage.