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Click on “Download PDF” for the PDF version or on the title for the HTML version. If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options. Fate of Listeria innocua during Manufacturing and Ripening of Camembert CheesePublished by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org Citation: Paper number NABEC-04-0024, 2004 Special Meeting Papers . (doi: 10.13031/2013.16117)Authors: Shaowei Liu, Virendra M Puri, Ali Demirci Keywords: innocua, Camembert cheese, ripening, survival and growth The ability of Listeria innocua to survive and grow during ripening of Camembert cheese was studied. Pasteurized whole milk containing about 5 log10 CFU/ml of L. innocua (ATCC 33090) was used to make Camembert cheese. All cheeses were ripened in three stages: room temperature ( ~20C) and relative humidity 60% (36 hours); 12C and relative humidity 93% (2 weeks); and 7C and relative humidity 85% (3 weeks). During ripening, surface and interior of cheeses were analyzed for population of L. innocua by surface plating on Brain Heart Infusion agar. The data were collected on day 1, 5, 10, 15, 20, 25, 30, and 35 during ripening. Results showed that population of L. innocua on day 1 was around 7.16 log10 CFU/g which was 2.40 log10 CFU/g increase over the initial inoculation of 4.76 log10 CFU/g. For subsequent 20 days, L. innocua population density declined to 6.54 log10 CFU/g. Thereafter, L. innocua population increased to 7.38 log10 CFU/g on day 35 of ripening. Generally, the growth of L. innocua is faster in surface than in center location. Top center, bottom center and bottom surface locations had similar population during ripening. There were no significant differences (P>0.05) between batch and section of cheese. The ripening time and locations had significant effect (P<0.05) on the survival and growth of L. innocua. (Download PDF) (Export to EndNotes)
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