Effectiveness of the Thermal Treatments Used for Curd Stretching in the Inactivation of Shiga Toxin-Producing O157 and O26 Escherichia coli

Table 3

Differences between the observed reduction of O157 and O26 Shiga toxin-producing Escherichia coli and the estimates produced on the basis of the inactivation kinetics of E. coli O26 and O157:H7 in mozzarella curds.

STEC serogroup	Temperature profile	Mean reduction (95% confidence interval)		Statistical significance
		Observed	Estimated
O157	1	>5.37 (4.87–6.67)	4.36 (4.00–4.85)
	2	>4.99 (4.48–6.29)	4.99 (4.24–5.16)
	3	3.82 (3.20–4.50)	2.59 (0.94–3.47)
O26	1	4.43 (3.81–5.24)	3.68 (2.95–4.41)
	2	3.55 (3.13–4.20)	2.68 (2.04–3.42)
	3	4.98 (4.28–6.30)	3.97 (3.02–5.07)

Values calculated from the difference between the counts in curd () and in “pasta filata” (). Differences with symbol > indicate MPN counts below the limit of quantification at the end of stretching.