Secondary Shelf Life: an Underestimated Issue

Shelf life and related issues are generally discussed and studied on packed foods. However, when original containers are opened by consumers or at industrial level, a sharp acceleration of product quality decay suddenly occurs. In these cases, the concept of secondary shelf life (SSL), that is the period after pack opening during which a food product maintains an acceptable quality level, should be introduced. SSL and related issues (e.g. food safety, quality, and consumer perception after pack opening) have received little attention in literature despite the possible remarkable impact on household management of opened products by consumers as well as on food industry management of raw material and semi-processed foods after opening. In this review, the SSL issues are critically discussed by focussing on possible spoilage events after pack opening, consumer and food industry perspectives on SSL, and SSL assessment process.