ESL / Aseptic
ESL/Aseptic is a comprehensive sterilization method for both processing and packaging a product. Aseptic products are thermally processed to a state of commercial sterility and then filled through a sterile zone into a sterilized package. They are shelf-stable and do not require refrigeration.
The aseptic process and packaging procedures provide longer shelf life at normal room temperatures without preservatives. Shelf life can be extended (in some cases) for up to one year without refrigeration. Product sterilization occurs by rapidly heating the product to a high temperature, holding for a short period of time, and rapidly cooling the product. Products are minimally affected by the heating process, ensuring flavor retention, nutritional value and product integrity.
The choice of system, system design, filler and package are very product dependent. In order to ensure product integrity and system efficiency, it is crucial that the choice of process, filler and package is made based on the particular product being processed.
The types of processes accepted in the United States for the production of aseptic products are time/temperature based. The two types of time/temperature based processing systems are categorized as indirect and direct heating systems.
Indirect systems utilize non-contact heating and cooling media to achieve the desired product temperatures. These systems employ various types of heat exchangers such as plate, tubular or scraped surface heat exchangers to heat and cool products to conform to the desired product temperature profile.