Table 2.

Characteristics of curd, temperature profiles recorded during the stretching phase, and changes in the counts (log⁡MPN/g) of O157 and O26 Escherichia coli.

	E. coli serogroup
	O26						O157
Microbial starters∗	N	N	N	A	A	A	N	N	A
Curd pH	5.1	5.0	5.2	5.0	5.1	5.1	5.2	5.0	5.3
Temperature profile	nc	nc	nc	1	2	3	1	2	3
Temperature range (°C)	Time in seconds
56.1–64	325	102	147	21	22	6	23	144	109
64.1–66	650	204	294	21	22	6	16	69	68
66.1–68	11	90	27	14	18	6	17	69	102
68.1–70		40	1	12	13	4	24	75	39
70.1–72		4	1	4	27	9	32	88	10
72.1–74		2	1	7	24	16	40	134
74.1–76				56	10	38	68	14
76.1–78				19		36	221	9
78.1–80						10	12	10
>80								16
Max temperature	65	71	64	75	73	77	79	80	72
Stretching time (min)	21.9	9.1	10.3	1.9	1.5	1.9	7.9	12.8	5.1
Count before stretching	4.23	4.12	4.05	4.39	4.43	4.53	4.85	4.46	4.45
Count after stretching	3.04	1.36	3.04	−0.04	0.88	0.44	<−0.53	<−0.53	0.63

^∗N, natural whey left over from the previous day's cizza is added to lukewarm milk; A, artificial starter culture of Streptococcus thermophilus is inoculated in lukewarm milk; nc, not considered for the modelling purpose.