GB508333A - Process for the preservation of the juices of fruits, vegetables and the like - Google Patents

Abstract

508,333. Preserving fruit, vegetable, and like juices. TRZOSKA, F. April 22, 1938, No. 12094. Convention date, April 23, 1937. [Classes 14 (ii) and 49] Fruit, vegetable, and like juices are preserved by multi-stage treatment with alternating or polyphase electric currents, a large body e.g. 3,000-20,000 litres, being heated slowly to about 50‹ C., the deposits which collect at the bottom and the lighter albuminous material which rises to the top of the liquid being drawn off separately after which the clarified juice is drawn off into smaller containers of about 30-50 litres capacity and heated therein by the current very quickly to a temperature up to 68‹ C. and is then drawn off in a sterile condition. The preliminary treatment may be carried out in two or more stages. Dilution, mixture, sweetening, &c. of the liquid, e.g. addition of water and sugar, honey &c. to rhubarb, currant and other acid juices is carried out prior to the final stage. The juices are kept as far as possible out of contact with metal during crushing of the fruits, filtering and storage, the containers and ducts used being preferably made of wood, porcelain, glass, earthenware, stoneware, hard rubber, &c., or of metal having a suitable coating of vitreous enamel, synthetic resin, &c. The juices are kept out of contact with air during the treatment by using closed vessels and keeping them filled with.liquid. The electrodes used may be of metals such as platinum, osmium, tungsten or molybdenum, or metalloids such as graphite, and may be disposed near the bottoms of the treatment vessels. During the treatment in the smaller vessels filtered air may be driven by sharp impulses through the liquid to ensure mixing and uniform treatment. The treated juice may be drawn off into bottles &c. which are completely filled and immediately sealed before the liquid cools. With grape juice, after the preliminary treatment the juice may be kept for some weeks or months, the treatment being if necessary repeated, prior to carrying out the final stages.