Recent developments in the fish by‐products industry
Author(s) -
Lovern J. A.
Publication year - 1955
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740060501
Subject(s) - raw material , fish meal , food science , fish processing , fish <actinopterygii> , recipe , food processing , pulp and paper industry , dried fish , fish oil , fish products , food industry , chemistry , environmental science , biology , fishery , engineering , ecology
Abstract The main fish‐by‐products industry deals with the production of protein feeding‐stuffs and oil from the processing of offal and from fish unsalable for human food. According to whether the raw material is rich or poor in fat, the industry has developed along somewhat different lines. Two recent developmental trends are ( a ) the introduction of pneumatic (air‐lift) driers having relatively low drying temperatures and very short drying times, with high capacity in relation to size of unit, and ( b ) the increasing interest in alternative products to conventional fish meal. These are peptized products in which the protein has been largely converted into water‐soluble fragments by acid treatment, or by ensiling the fish with a fermentable carbo‐hydrate (e.g. molasses) and a lactic‐acid‐producing organism. The efficient processing of oily raw material is particularly handicapped by alternating gluts and scarcities of fish, and some methods of storage of raw material are being studied including preservation by addition of alkali, formaldehyde and sodium nitrite or by preservation of a half‐processed commodity such as press‐cake. The seasonal nature of certain fisheries and the migratory habits of the fish, e.g. herrings, have led to many proposals for floating oil and meal factories. The economics of this are far from simple, but development along these lines is in progress in certain areas. Processing of oily material usually involves the expression of about half the total water along with the oil. In some countries, e.g. the U.S.A., the aqueous fluid is concentrated and marketed as a special product, ‘condensed fish solubles’, but the present trend in Europe at least is to return the material in some form to the final meal. Certain otherwise highly efficient types of drier, e.g. the flame drier, have in the past been operated without any attempt to deodorize the large volumes of effluent vapour. A modern development is the designing and increasing use of water‐scrubbing plant for driers of this type. However, the introduction of pneumatic (air‐lift) driers, with enormously increased amounts of effluent air, has brought with it a new problem if deodorization is found to be as necessary as with other types of drier.