Behavior of Enteropathogenic Escherichia coli in Camembert Cheese Made From Ultrafiltered Milk

Abstract

Skimmilk retentates from ultrafiltration (UF) were used in combination with concentrated cream (67% milk fat) to prepare a liquid precheese mixture that with the addition of rennet, lactic starter culture and a mold spore preparation of Penicillium candidum was transformed readily into Camembert cheese upon ripening. Yield increases from the retention of soluble milk protein, closer weight control tolerances for individual cheeses and reduction in rennet in comparison to the conventional Camembert process were observed. The behavior of enteropathogenic E. coli (ECC) serotypes was demonstrated in the Camembert cheese made from UF processes. Relationships were determined in UF Camembert as to microbial type and numbers used to inoculate the precheese, and as to site of survival and growth of different EEC serotypes. Differences which were observed in the physicochemical properties between conventional and UF cheesemilk mixtures predisposed the UF Camembert cheeses to greater E. coli survival and growth than in the Camembert cheeses made conventionally.

Physicochemical properties and secondary microflora variability in the manufacture and ripening of Idiazabal cheese

“…This confirms the results of other authors who have shown that E. coli was one of the most resistant species within Enterobacteriaceae during ripening of cheeses [47]. Generally, Salmonella is not detected in long-time ripened pressed cheeses with low pH, as in our case [18].…”

Influence of a gel microstructure as modified by gelatin concentration on Listeria innocua growth

“…However, high buffering capacity of food products had been found to offer protection to microbial cells. For example, Rash and Kosikowski (1982), in their study of certain enteropathogenic bacteria such as E. coli growth in ultrafiltered milk, reported that the increased buffering capacity of the milk provides a good environment for the growth and survival of the bacteria. Misty and Kosikowski (1986) also reported a minimized bacterial cell damage of lactic acid bacteria when growth was studied in a highly concentrated ultrafiltered skim milk, which they attributed to the high buffering capacity of the milk which maintains the pH at high levels for long period.…”

Buffering capacity of dairy products

“…For the manufacture of Camembert cheese made from pre-cheese, mineral composition has to be appropriate to obtain acid pH by the use of selected bacterial cultures in optimal buffering capacity conditions (Mistry & Maubois, 2004;Rash & Kosikowski, 1982).…”