Using Predictive Models for the Shelf‐Life and Safety of Seafood

Abstract

In terms of quality, the seafood industry needs to know what their products will look, smell, and taste like when it is consumed next week in the case of a chilled product, or next year in the case of a frozen product. With regard to microbial safety, the seafood industry needs to not only know that its products are safe now but will be safe next week when their customers eat them. However, because tests take time to complete, microbiologists can only confirm that a product was safe a few hours, or more often, a few days ago. For the seafood industry, predicting the future is not an optional feature. It is an essential for doing business. It is this need that predictive modelling of seafood shelf-life and safety is designed to address.Although great progress has been made in the science and mathematics of predictive food modelling over the last four decades, it is beyond the scope of this chapter to review all of this. Books have been written on this subject [1-3] and international conferences [4] provide effective reviews of advances in the area. This chapter highlights predictive models that have been developed specifically for seafood.Two main types of models are usually used in predictive modelling.1) Primary models indicate the effect of time on a particular attribute (e.g. bacterial number) under particular constant processing or storage conditions (e.g. 0 • C storage). 2) Secondary models indicate how parameters derived from the primary model (e.g. the bacterial growth rate) change in response to the product being held under different constant processing or storage conditions (e.g. temperatures between -5 and 20 • C).A number of predictive models for food have been incorporated into software packages (socalled tertiary models). The user can input their product and environmental parameters and obtain predictions of microbial numbers or product quality at selected times. Dalgaard [5,6] has produced and made freely available an invaluable piece of software for predicting seafood safety and spoilage under various conditions (Fig. 20.1). The software contains 15 models to predict the shelf-life and safety of seafood and can be accessed in 15 languages. The Fish Shelf-life Prediction Program [7], an add-in for Excel, is also freely available. It models Handbook of Seafood Q uality, Safety and Health Applications Edited by Cesarettin Alasalvar, Fereidoon Shahidi, Kazuo Miyashita and Udaya Wanasundara