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Model Exponential model for RRS of cold-smoked salmon
Reference Dalgaard, P, Murillo, E. and Jrgensen, L.V. 2004. Modelling the effect of temperature on shelf-life and on the interaction between the spoilage microflora and Listeria monocytogenes in cold-smoked salmon. Chapter 22  In: Shahidi, F. and Simpson, B. K. (eds), Seafood Quality and Safety. Advances in the new millennium. ScienceTech Publishing Company, St. Johns, Newfoundland, Canada, pp. 281-302
Factor(s) in model Temperature
Range of applicability Vacuum-packed cold-smoked salmon stored between 0C and 25C
Product validation studies:
Sliced and vacuum packed cold-smoked salmon at constant and fluctuating temperatures between 5C and 15C Dalgaard et al. (2004), Lakshmanan and Dalgaard (2004)
Hot-smoked and aerobically stored eel, halibut and herring  Dalgaard et al. (2004)


The exponential spoilage model shown below is used in FSSP for the effect of temperature on RRS of sliced and vacuum packed cold-smoked salmon. 

Ln(RRS) = 0.089 x TC                                                                Eqn. 1

When vacuum-packed cold-smoked salmon was stored at temperatures that changes between 5C and 15C this model predicted shelf-life appropriately as shown in the Table just below.

  Storage temperature    Shelf-life (days)
Sub-batch Phase I (8.9 days) Phase II   Observed Predicted
A 5 C 15 C   20.0 20
B 15 C 5 C   25 24

Eqn. 1 predicted the effect of temperature on RRS of sliced and vacuum packed cold-smoked salmon corresponding to bias- and accuracy factors of 0.87 and 1.40, respectively (See Table below). However, more accurate predictions, corresponding to bias- and accuracy factors of 0.91 and 1.18 were obtained for hot-smoked eel, halibut and herring stored aerobically between 2C and 20C. Equations uses to calculate bias- and accuracy factors based on RRS-data are shown in Eqn. 2 and 3.


                         Eqn. 2

                                 Eqn. 3




Shelf-life (d) and storage temp. (C)

Shelf-life (d) and storage temp.(C)

Observed relative rates of spoilageb Predicted relative rates of spoilage
Vacuum 4.1 25 d, 0C 21 d, 5C 1.2 1.6
Vacuum 4.1  21 d, 5C 14 d, 10C 1.5 1.6
Vacuum 5.0 20 d, 6C 6.5 d, 12C 3.0 1.7
VP, Riloten


27 d, 5C 13 d, 10C 2.1 1.6
VP. Amilon 4.3 21.5 d, 5C 18 d. 10C 1.2 1.6
Vacuum 4.6 31.5 d, 5C 10.5 d, 10C 2.5 1.6
Vacuum 4.6 52.5 d, 5C 38.5 d, 10C 1.3 1.6
Vacuum 6.6 60 d, 2C 20 d, 10C 3.0 2.0
Bias  factor 0.87
Accuracy factor 1.40
a) Water phase salt (WPS)
b) Relative rates of spoilage calculated as shelf-life at the lowest storage temperature divided by shelf-life at the highest storage temperature