Improvements in or relating to processes for pretreating vegetables or fruits

摘要

629,251. Blanching vegetables or fruits. CENTRAAL BUREAU VAN DE TUINBOUWVEILINGEN IN NEDERLAND. March 13, 1946, No. 7812. Convention date, May 30,1941. [Class 49] For blanching preparatory to freezing, drying, or canning, vegetables or fruits are subjected in a closed chamber to a stream of hot air or gas having a humidity such that its wet bulb temperature is between 65‹ and 100‹C. With the batch apparatus of Fig. 1a mixture containing 0.95 kg. of steam to 1 kg. of air, initially heated by a heater to 125‹C and so of wet bulb temperature 85‹C is circulated over sliced carrots spread on a tray 4 to the extent of 20 kg./mSP2/SP. After 200 sec. the temperature of the carrots is 86‹C. With the continuous apparatus of Fig 2 peas are spread to the extent of 7 kg./mSP2/SP on a travelling belt 13 and conveyed for 60 sec. through a chamber 17 and therein subjected to a steam-air mixture heated by a heater 11 to 95‹C and of wet bulb temperature 90‹C, air for maintenance of this humidity being introduced through an opening 20 provided with an adjustable flap 19.