Production and frozen storage of minced Baltic herring (Clupea harengus membras)

Abstract

AbstractThe production and storage of minced Baltic herring was investigated to develop a convenient semi‐finished product which could be manufactured industrially and stored frozen as such or in the form of pre‐manufactured convenience foods. Baltic herring has several disadvantages as a raw material for such use, namely small size, dark colour, strong odour, and soft texture. Dark colouring of the mince can be reduced considerably by skinning. The dark pigments of the belly lining are eliminated on filleting. The strong odour which evolves when Baltic herring is heated can be moderated by adding a small amount of suitable protein such as milk protein. This addition also has a positive influence on the water binding capacity and taste of the mince. The texture is improved by adding barley or wheat starch or possibly by pre‐texturing part of the mince by heating to give a heterogeneous structure. Fish are skinned prior to mincing and 0.1–0.2% ascorbic acid or sodium erythorbate is added as antioxidant. The mince is vacuum packed in a gas‐tight material such as polyethylene/polyamide laminate. In this way it is possible to store frozen minced Baltic herring at −25 °C for at least one year. Even after such a period the mince is still quite acceptable and no rancidity or peroxides can be detected. Although it appears that certain adverse protein changes cannot be avoided during frozen storage, their effects can be masked in part by adding milk protein, starch and triphosphate to increase the water‐binding capacity and generally improve the functional properties of the mince and mince‐based products.