Estimating the efficacy of mild heating processes taking into account microbial non-linearities: a case study on the thermisation of a food simulant
Food Control, Vol.22, 1, 2010 Available from the publisher here http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6T6S-50FGY2J-C-7&_cdi=5038&_user=2322584&_pii=S0956713510001805&_origin=browse&_zone=rslt_list_item&_coverDate=01%2F31%2F2011&_sk=999779998&wchp=dGLbVtz-zSkzV&md5=988c7407607f885ff2a53f80921aa2c9&ie=/sdarticle.pdf
Traditional and novel approaches for the calculation of the heat treatment efficiency are compared in this work. The Mild Heat value (MH-value), an alternative approach to the commonly used sterilisation, pasteurisation and cook value (F, P, C–value), is calculated to estimate the efficiency of a mild heat process. MH-value is the time needed to achieve a predefined microbial reduction at a reference temperature and a known thermal resistant constant, z, for log-linear or specific types of non log-linear microbial inactivation kinetics. An illustrative example is given in which microbial inactivation data of Listeria innocua CLIP 20-595 are used for estimating the inactivation parameters under isothermal conditions of 58, 60, 63 and 66oC by the use of the log-linear and the Geeraerd et al., (2000) model. Thereafter, dynamic temperature profiles (targeting at 54 and 57 C) representing milk thermisation are exploited for illustrating the application of MH-value. Finally, the equivalent holding times of different temperatures are calculated taking into account the observed non-linearity.