• Smolander, Maria

Abstract

The idea of diagnostic packaging is that the package itself or a smart indicator label attached to the package can give information about the product quality directly, about the package and its headspace gases or about the storage conditions of the package. A freshness indicator indicates the microbial quality of the product by reacting directly to the metabolites produced in the growth of micro-organisms. If perishable food products are stored above the suggested storage temperature, a rapid microbial growth takes place. The product is spoiled before the estimated "use by" -date and in the worst case growth or toxin production of pathogenic bacteria takes place. Time-temperature indicators attached on the package surface integrate the time-temperature history of the package throughout the whole distribution chain and hence give indirect information on the product quality. For many perishable products exclusion of oxygen and high concentration of CO₂ improves the stability of the product as the growth of aerobic micro-organisms is prevented. As a resultof potential package leak the protecting atmosphere is deteriorated. Packageleak can also increase the microbial spoilage by enabling the productcontamination with harmful micro-organisms. It is possible to check thepackage integrity immediately after packaging procedure, but a leak indicatorattached into the package gives information on the package integritythroughout the whole distribution chain.The development and testing of diagnostic indicators in confidential andnon-confidential projects has been one of the key focuses of the packagingresearch at VTT Biotechnology for about ten years. Non-confidential researchfinanced by European Commission, Finnish Ministry of Agriculture and Forestry,Association of Finnish Fish Retailers, National Technology Agency (Tekes) inFinland and industrial sponsors has been carried out. During these projectsprototypes of leak indicators and freshness indicators especially for poultryproducts have been developed and tested. Related to the development offreshness indicators metabolites reflecting the quality of poultry meat havebeen investigated. We have also carried out projects where the alreadycommercially available indicators have been applied for the quality control ofpackaged, fresh fish and poultry products.In this presentation the different types of diagnostic indicators will bebriefly reviewed and examples of case studies carried out at VTT Biotechnologywill be described.

Topics

• impedance spectroscopy
• surface
• Oxygen