GB938381A - Dehydrated purees and method and apparatus for preparation thereof - Google Patents

Abstract

938,381. Dehydrated and flaked food. GENERAL FOODS CORPORATION. May 20, 1960 [May 20, 1959; June 4, 1959; July 2, 1959], No. 17835/60. Class 49. Rapidly reconstitutable dehydrated food flakes are produced by concentrating a puree, i.e. a liquid or semiliquid food material of 9 to 30% solids content and having a relatively high percentage content of natural or added sugars and/or pectinous substances, to a moisture content of from 2 to 15%, forming it into a film, e.g. 0.005 to 0.050 inch thick, on a heated surface, and while still plastic, e.g. at 212‹ F., stretching the film sufficiently to produce minor ruptures in it without breaking its continuity. The film is then cooled, if necessary, e.g. to below 70‹ F., using refrigerated, dehumidified air, dried and broken into flakes at below 30‹ F. of a size passing a 10-mesh sieve (U.S. Standard) but not a 40 mesh sieve. The puree may comprise comminuted fruit and/or vegetable solids and/or juices, meat solids, dairy products, flavourings and include, if necessary, one or more added stretchable film-forming substances, e.g. starches, polysaccharide and/or cellulose ethers such as pectin, algin, Irish moss extract, gum arabic or acacia, alkali metal carboxymethyl celluloses, ethyl, methyl or other celluloses or hydroxycelluloses, and proteinaceous mineral or vegetable matter such as soybean or peanut protein or fish protein. As shown, Fig. 3, a puree is delivered to the nip between steam-heated drums 20, 22 spaced 0.006 to 0.015 inch apart, where it is concentrated before forming a thin film on the drum surfaces which is doctored off at 24 and taken over a tension applying stretched roll 30 of woven wire or expanded metal, through which suction may be applied, if desired, the film being pressed on to the roll surface by hard rubber rider wheels 32 (or a single roll with spaced circumferential grooves gouged out). The curtain of film then falls into a hopper and breaker assembly 42, Figs. 1 and 5, passing between guide wires 48 into contact with breaker arms 52 on a rotating shaft 54, the broken pieces entering a conveyer/flaker 28 comprising a screw 34 rotating in an insulated tube 36 through which a current of cold air is circulated via inlet 60 and outlet 62. Finally the broken product cascades over rotating flaker paddles 64 which brush it through a circumferential screen 68 inside a hopper 69. The refrigerated air system comprises, Fig. 4, not shown, in series from outlet 62 to inlet 60 a cyclone separator, a silica gel dryer, a heat-exchanger, a heating unit and a fan. The heating unit just slightly warms the chilled air, rendering it capable of taking up more moisture.