P. Dalgaard et al., APPLICATION OF AN ITERATIVE APPROACH FOR DEVELOPMENT OF A MICROBIAL MODEL PREDICTING THE SHELF-LIFE OF PACKED FISH, International journal of food microbiology, 38(2-3), 1997, pp. 169-179
An iterative approach was used to develop a microbial model for shelf-
life prediction of cod fillets packed in modified atmospheres. The eff
ect of temperature (0-15 degrees C) and CO2 (0-100%) on growth of the
specific spoilage organism, Photobacterium phosphoreum, was studied in
packed cod and in liquid media. P. phosphoreum was a dominant part of
the spoilage microflora of packed cod stored at the extremes of the r
ange of conditions studied. The organism is therefore likely to be imp
ortant for spoilage and the development of a microbial model within th
is domain seems relevant. A liquid medium was developed to provide gro
wth kinetics of P. phosphoreum similar to those observed in packed cod
. Using this medium, the effect of temperature and CO2 on the maximum
specific growth rate of Photobacterium phosphoreum was determined by a
bsorbance measurements and modelled by a square root equation and by a
polynomial equation. Product validation studies were carried out duri
ng summer and winter using naturally contaminated packed cod fillets w
hich were stored at constant and at changing temperatures. The shelf-l
ife of the packed fillets was predicted on the basis of the initial nu
mbers of P. phosphoreum, product temperature profiles and the level of
CO2 in the modified atmosphere. The average deviations between shelf-
life determined by sensory evaluation and shelf-life predicted by the
square root equation and by the polynomial equation were 17% and 9%, r
espectively. (C) 1997 Elsevier Science B.V.