USE OF PHASE CHANGE MATERIALS (PCM) TO KEEP SUPERCHILLED TEMPERATURES IN CONSUMER PACKAGES THROUGH THE COLD CHAIN

摘要

Superchilling of foods like fish, pork and poultry is known to increase the shelf-life of up to 100%. In western countries, 30% of the processed foods are thrown due to i.e. short shelf-life. Superchilling is a refrigeration technology where the product temperature is lowered to just below the initial freezing point, where 5-30% of the free water inside the product is frozen. A low amount of ice will not affect the quality compared with fresh chilled products. To utilize the maximal of increased shelflife, the superchilled cold chain cannot be broken, which leads to melting of the ice. Considering the whole cold chain from production, through distribution and supermarkets to the consumers, the complexity of keeping the superchilled temperature will increase. The technicalities to keep the products at superchilled temperatures in retail- and domestic refrigerators are not complex. Transportation of superchilled products from distribution centers to the supermarkets, and further from supermarkets to the customers gives a higher risk for breaking the cold chain, and loosing shelf-life. An innovative Phase Change Material (PCM) sachet was developed where the melting point was set to be -1.7°C which correlates with ～20% ice inside the product. A comparative study was performed to see if the phase change enthalpy of the PCM sachets was preventing the superchilled products inside consumer packages to melt during a shorter temperature increase of the ambient air.