Method and apparatus for dry broths or blanching of vegetable

摘要

1354644 Blanching vegetables or fruit MAGNUSON ENGS Inc 26 July 1972 [25 Aug 1971] 34984/72 Heading A2D A process for dry blanching vegetables or fruit comprises burning a fuel-air mixture in a recirculating fluid circuit to fill the circuit with combustion gases that are free of molecular oxygen and are heated by the combustion, maintaining the moisture content of the gases at a level substantially to prevent drying of the vegetables or fruit, introducing vegetables or fruit into a chamber within the circuit and forcibly circulating the gases around the circuit and over the surfaces of the vegetables or fruit in the chamber. The combustion gases preferably flow upwards and through the chamber at a velocity such as to form a fluidised bed of the vegetables or fruit. The combustion gases are preferably heated to a temperature of beween 230‹F and 270‹F, and the gases are circulated for a sufficient time to reduce the peroxidase level of the vegetables or fruit to at least 0.058. The process may be carried out in the apparatus shown in Fig. 1, wherein combustion gases are generated at the burner 17 and, to maintain the moisture content of these gases at a suitable level, are mixed with steam entering the apparatus via steam pipe 22. The gases are circulated via conduits 26 and 26a (Fig. 2, not shown) to treating zone 28. The zone is provided with a mesh-type conveyor belt 32 at its top and a similar conveyor 36, fitted with vertical partitions 37, at its base. Vegetables and fruit are fed into the apparatus from conveyor 40 and after blanching are removed by conveyor 41.