| 摘要 |
To extend shelf-life, a method of heat-treating a food packed in a packaging container of a packaging laminate comprising a layer of paper or paperboard and outer, liquid-tight coatings of plastic. The 9ackaging container is exposed to a liquid heating medium sprayed against outer walls of the packaging container to heat and hold the food at a predetermined treatment temperature during a predetermined period of time so as to exterminate, eliminate or deactivate harmful microorganisms inside the packaging container. Thereafter, the food is cooled by cold water sprayed against the outer walls of the packaging container. To avoid the risk that liquid penetrates into exposed incision edges on the outside of the packaging container during the heat treatment, the packaging container, before this treatment, is brought into contact with a hydrophobic impregnation agent for absorption and penetration of the hydrophobic impregnation agent in the exposed incision edges. |
