Assessment of the volume and material container influence on juice cooling process

Abstract

The quality of bottled beverages depends on the thermal process they undergo during the bottling process. The thermal history of the bottled beverage impacts the conservation of the product itself indeed. The temperature variation is related to specific aspects, such as the thermophysical properties, the heat exchange regime, and the possible simultaneous presence of more phases in the beverage itself. For instance, the behavior of the fluid inside the container might change according to the percentage of solid phases (e.g., pulp for juices). The present work addresses the cooling process on a processing line for beverage containers. This process aims to reduce the fluid temperature to preserve organoleptic characteristics and allows a stable and safe storage phase. The analysis has been carried out with a purpose-designed test bench to mimic the cooling process. Two juices with different percentages of solids (15 % and 50 %) are investigated for two container volumes (250 ml and 330 ml) and two container materials (glass and aluminum). The results show the influence of the pulp content on the cooling performance. The changes in the heat transfer performance determine different outlet temperature values and a different sensitivity to the container characteristics.