Blanching, pasteurizing and sterilizing process and apparatus suitable therefor

Abstract

A method is provided which permits continuous and rapid blanching or sterilization of foodstuffs in particulate form. The foodstuff is heated rapidly to penetrate the outer portion of the particle by steam or gas under pressure, the heated particles are maintained thereunder until inactivation or destruction of microorganisms and enzymes, after which the pressure and temperature are lowered rapidly.

I claim: 
     
       1. A continuous process for the rapid blanching and sterilization of foodstuffs in particulate form, such as portions of fruit, vegetables, meat or fish, which comprises continuously moving said foodstuff particles .Iadd.in a .Iaddend.first .Iadd.zone .Iaddend.through an elongated pressure chamber where .[.it is.]. .Iadd.the same are .Iaddend.subjected under pressure to hot steam or gas .Iadd.at a temperature and for a time sufficient .Iaddend.to rapidly heat the outer portion thereof .[.an.]. .Iadd.and .Iaddend.to supply .Iadd.thereto .Iaddend.sufficient heat to heat the foodstuff particles .Iadd.when spread .Iaddend.throughout .Iadd.the same .Iaddend.to the sterilization temperature thereof, then moving the thus heated foodstuff particles .Iadd.in a second zone .Iaddend.through an elongated chamber where the pressure drops and said particles are maintained under .Iadd.essentially .Iaddend.adiabatic conditions until the particles attain the sterilizing temperature throughout for the time necessary to inactivate or destroy the microorganisms and enzymes .Iadd.and thus sterilize the food particles.Iaddend., then moving the .Iadd.thus sterilized .Iaddend.particles of foodstuff .Iadd.in a third zone .Iaddend.through a cooling unit to effect cooling of the product, .Iadd.and .Iaddend.moving the cooled product through an enclosed conveying system to a packing unit where it can be packed asceptically, .[.all of the.]. movement of the foodstuff particles being effected at least partly by gravity feed. 
     
     
       2. Apparatus for carrying out the .Iadd.continuous .Iaddend.process of rapid .[.heat.]. blanching .Iadd.and sterization .Iaddend.of foodstuff particulates which comprises an elongated .Iadd.gas or .Iaddend.steam pressure chamber through which the foodstuff first moves, an adjacent elongated chamber .Iadd.connected to said pressure chamber and being .Iaddend.under a pressure lower than .Iadd.that of .Iaddend.said .Iadd.gas or .Iaddend.steam pressure chamber through which the foodstuff next moves and wherein the pressure drops while the foodstuff is adiabatically .[.heatedΘ .Iadd.equilibrated throughout to the sterilization temperature thereof, .Iaddend.a cooling unit connected to said adjacent elongated chamber through which the adiabatically .[.heated.]. .Iadd.equilibrated and sterilized .Iaddend.foodstuff then passes and is there cooled, and an elongated enclosed conveying system connected to said cooling unit and to a packing unit for conveying the foodstuff to the packing unit, .[.all of.]. said chambers and units being connected and angled to .[.give a.]. .Iadd.effect movement of the foodstuff particles at least partly by .Iaddend.gravity feed. .Iadd.3. A continuous high-temperature short-time process for the rapid blanching and sterilization of foodstuffs in particulate form, such as portions of fruit, vegetables, meat or fish, which comprises continuously moving said foodstuff particles through a first zone where the same are subjected under pressure to hot steam or gas at a temperature and for a time sufficient to rapidly heat the outer portion thereof and to supply thereto sufficient heat to heat the particles when spread throughout the same to the sterilization temperature thereof, then moving the thus heated foodstuff particles through a second zone contiguous with said first zone where the pressure drops and said particles are allowed to equilibrate adiabatically until the particles attain the sterilization temperature throughout for the time necessary to inactivate or destroy the enzymes and microorganisms present, then moving the foodstuff particles through a third zone contiguous with said second zone to effect cooling of the product, and then moving the cooled product to a packing unit connected to said third zone where the said product can be packed aseptically. 
     
     
        .Iaddend. .Iadd.4.  Apparatus for carrying out a continuous high-temperature short-time process for the rapid blanching and sterilization of foodstuffs in particulate form which comprises an elongated pressure chamber having means which support and convey the particles and means to pass hot steam or gas along said pressure chamber to provide a first zone through which the particles first move while being subjected under pressure to hot steam or gas; an adjacent elongated chamber connected to said pressure chamber and being under a pressure lower than that of said pressure chamber to provide a second zone through which the particles next move and wherein the pressure drops while the particles are allowed to equilibrate adiabatically whereby the particles attain a sterilization temperature throughout; a cooling unit connected to said adjacent elongated chamber to provide a third zone through which the sterilized particles then pass and are there cooled; and an elongated enclosed conveying system connected to said cooling unit and to a packing unit for conveying the foodstuff to the packing unit. .Iaddend.