| 摘要 |
To sterilize a foodstuff it is heated to a temperature level T1 over its melting temperature Ts. During the heating phase, steam is distributed finely through the foodstuff, which is heated to a temperature T2 where microorganisms and their spores are destroyed. The foodstuff is subjected to a pressure p1 which is over atmospheric pressure levels, and the water content is reduced to ≤ 5 wt. %. To sterilize a foodstuff which is solid at room temperature, and contains fat and sugar with a water content of ≤ 5 wt. %, it is heated to a temperature level T1 over its melting temperature Ts. During the heating phase, steam is distributed finely through the liquid foodstuff, which is heated to a temperature T2 where any microorganisms and their spores are destroyed. The foodstuff is subjected to a pressure p1 which is over atmospheric pressure levels, and the water content is reduced to a level of ≤ 5 wt.%. After the foodstuff temperature has reached the T2 level, it is held at this temperature for a time period. Steam is introduced into the foodstuff during the total heating time span. The foodstuff is mixed through mechanically, while the steam is added, using at least one rotating dissolving disk over a steam delivery jet. The mixing is also through a scraper at the container wall. The steam is saturated. The foodstuff is heated by direct contact heating, and/or indirectly. The heating and heating maintenance times together total 3-30 minutes or 5-15 minutes. The sterilizing temperature T2 is 100-140 degrees C or 115-130 degrees C. The pressure p1 is 2-4 bar as an absolute measurement. The water content is reduced by a vacuum. The sterilizing process is intermittent, and is maintained until a given charge has been sterilized, or it is a continuous operation. |
