A preliminary survey into the temperature conditions and residence time distribution of minimally processed MAP vegetables in Belgian retail display cabinets

Abstract

Retail display cabinets are shown to be critical points in the cold chain of minimally processed, modified atmosphere packed (MAP) vegetables. Variations in residence time of three categories of minimally processed MAP vegetables were analysed in two local supermarkets using a stimulus-response technique. More than 50% of the packages (median) were sold in the first day, but the range indicates that some of the packages were sold after the ‘use by’ date. Mean residence time increases with increasing shelf-life, and for products with a shelf-life of 3 and 4 days, the mean residence time was almost the same in both supermarkets. Temperature performance of the display cabinets was influenced by both ambient temperatures and day/night regime. Temperature differences of more than 5 °C were measured on the decks. Temperature in one place increases towards the end of the day by 4 °C and towards the end of the week by almost 7 °C. Temperature monitoring and control based on the thermometer of the cabinets was impossible. Differences between the actual and read-out temperature of up to 10 °C were observed. This survey shows the necessity of a close control of temperature conditions and residence time of minimally processed MAP vegetables in retail display cabinets.