Up-grading of low value meats and by-products for use in consumer foods.

Abstract

The investigation was concerned with the up-grading of: (i) connective tissue material in the form of beef membrane, pig rind and turkey skin; (ii) muscle material from low-value cuts and from offals such as beef heart; (iii) heart muscle, by extrusion processing; (i) An emulsified material from beef membrane and beef replaced up to 5% of lean meat in corn beef and up to 10% in beefburgers without impairing cooked yield and eating quality. A collagen emulsion paste (CEP) from pig rind replaced up to 5% of lean meat in ham prepared from diced meat, and between 2 and 5% in ham prepared from whole muscles without reduction in cooked yield, texture, appearance and eating quality. Turkey skin was minced, chopped and incorporated at 10, 15 and 20% levels in a mix with turkey leg meat, which was used to make battered and breaded re-formed steaklets. Steaks containing up to 20% of emulsified skin were similar to control samples in flavour, juiciness and overall acceptability. An antioxidant may be required to prevent rancidity during frozen storage. (ii) Yields of surimi-like material, prepared by water-extraction, sieving and centrifuging, were 16% from lean of topside of beef (used as control for comparison), 39% from beef heart, 17% from pork mechanically recovered meat, 11% from beef weasand and less than 5% from beef cheek meat. The beef heart surimi was studied for its gelation properties and for its performance as an ingredient replacing lean meat in frankfurters and in beefburgers at levels between 3 and 15%. In frankfurters the addition of the surimi reduced cook loss and increased tenderness. For overall eating quality the frankfurters with 7 or 10% of surimi were preferable, and those with 15% equal, to those with none. In beefburgers cook loss was decreased from 32 to 25% by the addition of 15% surimi. Other results were similar to those for frankfurters, showing that the surimi could be added at 10 to 15% level without impairing texture or flavour. (iii) Cold extrusion processing of beef heart muscle with the aim of increasing its functionality showed that gelation properties of the material were not improved by extrusion compared to bowl chopping; moreover, the extruded product had a strong odour and dark colour.