High-Pressure Processing of Turkish White Cheese for Microbial Inactivation

• Published in: Journal of food protection 2008, Vol.71 (1), p.102-108
• Main Authors: Evrendilek, G.A, Koca, N, Harper, J.W, Balasubramaniam, V.M
• Format: Article
• Language: English
• Subjects: aerobes; Animals; Biological and medical sciences; Cheese - microbiology; cheese milk; Colony Count, Microbial; Consumer Product Safety; Enterobacteriaceae; Enterobacteriaceae - growth & development; Food Contamination - analysis; Food Handling - methods; Food industries; Food Microbiology; food preservation; Fundamental and applied biological sciences. Psychology; Fungi - growth & development; high pressure treatment; Hydrostatic Pressure; inactivation; inactivation pressure; lactic acid bacteria; Lactobacillus; Lactococcus; Listeria monocytogenes; Listeria monocytogenes - growth & development; Milk; Milk and cheese industries. Ice creams; molds (fungi); pasteurized milk; plate count; Temperature; Time Factors; traditional foods; Turkey; water activity; white cheeses; yeasts; Yeasts - growth & development
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028X-71.1.102

High-pressure processing (HPP) of Turkish white cheese and reduction of Listeria monocytogenes, total Enterobacteriaceae, total aerobic mesophilic bacteria, total molds and yeasts, total Lactococcus spp., and total Lactobacillus spp. were investigated. Cheese samples were produced from raw milk and pasteurized milk and were inoculated with L. monocytogenes after brining. Both inoculated (ca. 10(7) to 10(8) CFU/g) and noninoculated samples were subjected to HPP in a high-pressure food processor at 50 to 600 MPa for 5 and 10 min at 25 degrees C. Reductions in L. monocytogenes, total aerobic mesophilic bacteria, Lactococcus spp., and Lactobacillus spp. in both pasteurized- and raw-milk cheese samples and reductions in total molds and yeasts and total Enterobacteriaceae counts in raw-milk cheese samples increased with increased pressure (P less than or equal to 0.05). The maximum reduction of the L. monocytogenes count, ca. 4.9 log CFU/g, was obtained at 600 MPa. Because of the highly inhibitory effect of pasteurization, the total molds and yeasts and total Enterobacteriaceae counts for the cheese samples produced from pasteurized milk were below the detection limit both before and after HPP. There was no significant difference in inactivation of L. monocytogenes, total aerobic mesophilic bacteria, Lactococcus spp., and Lactobacillus spp. under the same treatment conditions for the raw milk and pasteurized milk cheeses and for 5- and 10-min treatment times (P > 0.05). No significant change was detected in pH or water activity of the samples before and after HPP. Our findings suggest that HPP can be used effectively to reduce the microbial load in Turkish white cheese.