Temperature function integration as the basis of an accelerated method to predict the shelf life of pasteurized, homogenized milk

Predictive Microbiology for Monitoring Spoilage of Dairy Products with Time‐Temperature Integrators

“…In the square root model l& vs T was plotted (Fig. 6) and a Tmin = -7.65 'C was obtained, similar to results from the growth rate (log phase), Similar Tmin values from both lag and log phase parameters were also reported by Chandler and McMeekin (1985) for a pseudomonad and by Smith (1985) for E. COG.…”

“…For example, Ingraham et al (1983) indicated, for E. coli, that the calculated Tmi, value was 3.5 "C while the true determined minimum growth temperature was 8 "C. Equation (2) has been successfully applied by Ratkowsky et al (1982Ratkowsky et al ( , 1983 to many data sets (Mohr and Krawiec, 1980;Reichardt and Morita, 1982). The effect of temperature on lag phase of growth has also been described by the square root model (Chandler and McMeekin, 1985;Griffiths and Phillips, 1988;Smith, 1985), with k equal to the inverse of the fag time.…”

Prediction of the shelf‐life of pasteurized milk at different storage temperatures

“…Previous work on a limited number of samples also showed that To values for the microflora of pasteurized milks varied but no attempt was made to relate this to keeping quality (Chandler & McMeekin 1985b). The constant (b) in the square root equation was relatively unchanged between pasteurized milk samples in this study and averaged 6.…”

“…A To value of 263 K has been used as being representative of common psychrotrophic spoilage bacteria (McMeekin & Olley 1986). However, it was suggested that for growth of psychrotrophs in raw and pasteurized milk, a To value of 264.5 was more appropriate (Chandler & McMeekin 1985a, 1985b. It has recently been shown that the To value for naturally contaminating microflora of pasteurized milks varied considerably in the range 2 6 2 7 3 K (Griffths & Phillips 1988).…”

“…Another technique, temperature function integration, is claimed to provide an indication of growth rates of spoilage bacteria in pasteurized milks at various storage temperatures (Chandler & McMeekin 1985b). This electrical device responds to temperature in a way dictated by the 'square root' equation of Ratkowsky et al (1982,1983 where m is a growth parameter (e.g.…”