Shelf-life determination and challenge testin G. Betts and L. Everis, Campden and Chorleywood Food Research Association 10.1 Introduction All food products are susceptible to deterioration in their quality during storage Chilled foods in particular are highly perishable and the time during which the quality is maintained at a consumer acceptable standard can be termed the shelf- life. The definition of shelf-life has been given by several authors as the time between the production and packaging of the product and the point it becomes unacceptable under defined environmental conditions(Ellis 1994)or the time at which it is considered unsuitable for consumption(Singh 1994). The end of products shelf-life will be due to deleterious changes to quality caused by biological, chemical, biochemical and physiochemical means, or by food safety concerns due to the growth of food pathogens which may not necessarily cause any changes in product quality There are few reference books available which give lists of shelf-lives for chilled foods as the shelf-life of each specific product is unique and based on the particular recipe, raw ingredients and manufacturing and storage conditions used. If there are any changes to these, then the shelf-life will be liable to change (see Section 10.2). Whilst there is some guidance available in the literature for chilled foods(Ellis 1994)and MAP foods(Day 1992) the shelf-life of products should be defined scientifically during product development following the The rationale for arriving at a particular shelf-life will undoubtedly encompass safety, quality and commercial decisions. It is unlikely that all of these will be in agreement and the safety of the product must al ways assume the highest priority There are, however, many commercial and marketing pressures to consider which will put some constraints on whether the shelf-life obtained from microbiological10.1 Introduction All food products are susceptible to deterioration in their quality during storage. Chilled foods in particular are highly perishable and the time during which the quality is maintained at a consumer acceptable standard can be termed the shelf￾life. The definition of shelf-life has been given by several authors as the time between the production and packaging of the product and the point it becomes unacceptable under defined environmental conditions (Ellis 1994) or the time at which it is considered unsuitable for consumption (Singh 1994). The end of a product’s shelf-life will be due to deleterious changes to quality caused by biological, chemical, biochemical and physiochemical means, or by food safety concerns due to the growth of food pathogens which may not necessarily cause any changes in product quality. There are few reference books available which give lists of shelf-lives for chilled foods as the shelf-life of each specific product is unique and based on the particular recipe, raw ingredients and manufacturing and storage conditions used. If there are any changes to these, then the shelf-life will be liable to change (see Section 10.2). Whilst there is some guidance available in the literature for chilled foods (Ellis 1994) and MAP foods (Day 1992) the shelf-life of products should be defined scientifically during product development following the procedures outlined in this chapter. The rationale for arriving at a particular shelf-life will undoubtedly encompass safety, quality and commercial decisions. It is unlikely that all of these will be in agreement and the safety of the product must always assume the highest priority. There are, however, many commercial and marketing pressures to consider which will put some constraints on whether the shelf-life obtained from microbiological 10 Shelf-life determination and challenge testing G. Betts and L. Everis, Campden and Chorleywood Food Research Association