GB416305A - Improvements in and relating to pectin and its manufacture - Google Patents

Abstract

Apparatus for drying pectous pulp or pomace or for producing a pectous film from a pectous liquor comprises a smooth unencumbered heated surface, e.g. a revolving drum heated interiorly, e.g. by steam, or a disc or a travelling metallic belt, and a scraper or knife, e.g. a flexible blade of stainless steel, for removing the dried pomace particles or the film from the surface. The film is usually obtained with a wavy irregular surface, but if desired a smooth film may be produced by drawing the film away from the knife as fast as it is formed.ALSO:A dry pectous film is manufactured by applying a relatively thin layer of pectous liquid directly to a smooth unencumbered heated surface, permitting the liquid to remain in contact with such surface sufficiently long to dry the liquid and form a substantially dry uniform coherent film which is then removed from the surface. The pectous liquid may first be obtained as follows: A pectous pulp or pomace, obtained by expressing the juice from pectin-bearing material, e.g. apples, oranges, lemons, grape skins or banana peel, is subjected, if desired, after grinding, but preferably in the unground state, to a drying operation by applying it to a smooth heated surface, e.g. a revolving drum heated interiorly, a disc or a travelling metallic belt. The temperature and time of drying are suitably co-ordinated, 12 seconds contact with a drum heated interiorly by steam at 17,5 pounds pressure (temperature 95 DEG C.) being suitable. The dried, somewhat tacky particles are removed by a suitable scraper or knife, e.g. a flexible blade of stainless steel, producing a film having an irregular surface of somewhat cr<\>zepe-like appearance, which can be folded to provide a laminated product filled with passages and channels. The dried pomace, ground or unground, is then leached, extracted and clarified in known manner to produce the pectous liquor, which may be used directly for the film-forming process or first concentrated to a syrup. The production of the film may be carried out in a similar manner to the drying of the pomace. In the case of a syrup, a suitable thickness for the liquid film is ,05-,06 inch, and suitable heating periods are 20 seconds on a cylinder heated interiorly with steam at 18 pounds pressure (surface temperature 222 DEG F., or 7,5 seconds with steam at 27 pounds pressure (244 DEG F.). The film may be removed as in the case of the dried pomace film, yielding a thin pectin film with a wavy irregular surface which may be folded to a laminated coherent mass filled with channels and passages. If desired, the wavy surface may be eliminated and a smooth film produced by drawing the film away from the knife as fast as it is formed.