GB676468A - Improvements in process for canning and sterilizing food products - Google Patents

Abstract

676,468. Canning foods. FOOD PROCESSES, Inc. Feb. 23, 1950 [March 24, 1949], No. 4703/50. Class 49. In canning and sterilizing foods, exemplified by milk, soups, syrups and juices, water-containing vegetables such as diced carrots, and meat, hash, chop suey, stew, corn, peas, carrots and other foods canned with sauce or other liquid, the food is heated in bulk, under sufficient atmospheric pressure to prevent boiling of the liquid of the food, to a temperature of from 260-310‹ F., is rapidly cooled in bulk to a filling temperature above the atmospheric boiling point of the liquid in the food, such heating and cooling comprising a heat treatment from 50- 97 per cent of that required for complete sterilization of the food, is filled and sealed, while under superatmospheric pressure above the boiling point pressure of the liquid at the filling temperature, in containers sterilized to the same degree as the food filled therein, and the filled and sealed containers are held under such superatmospheric pressure and approximately at such filling temperature for a period sufficient to complete sterilization of the food and the containers. The heating to the maximum temperature is, for example, in a time between 10 and 180 sec., the cooling to a filling temperature of from 230 to 270‹ F. in from 5 to 50 sec., and the holding at the filling temperature for a time of from 10 to 300 sec. With the apparatus of Figs. 1a and 1b, the process is carried out in a chamber 5, 6, 7, 8 in which is maintained a superatmospheric pressure: for a batch process, a kettle 21 of the food is run into the chamber, the food is poured from the kettle into one of a number of jacketted, agitating type heat exchanges E1, E2, E3, E4 and is there heated and then cooled; for a continuous process, the food is drawn from a hopper 23 by means of a rotary valve 24 into a heater H and advanced therein, with agitation, by a screw conveyer, and is cooled in a cooler C similar in construction to the heater H; the cooled food is delivered into a hopper 39 and is filled into cans 60 which have been partly sterilized in a compartment CS, lids 71 which have been partly sterilized in a compartment LS are sealed on to the cans, and the closed cans are held at substantially the filling temperature by passage on a serpentine conveyer S, the final cooling being in a bath 100 of water or brine.