Understand the functionality of meat proteins to create better products.

In processed meats, the functionality of meat proteins and nonmeat ingredients largely determines consumer acceptability. The water-holding capacity of the meat protein system directly influences drip loss, cooking yield, juiciness and tenderness scores in meat products. Understanding the functionality of meat proteins and nonmeat ingredients is essential for least-cost product formulation, and for the development of high-quality meat products and processes intended to upgrade low-value meats.

Current research aims to improve the quality of existing meat products, to upgrade low-value meats and meat by-products, and to develop high-quality new products. So far, European researchers have been able to add whey protein concentrates (WPCs) or whey protein isolate (WPI) to the salt-soluble protein (SSP) fraction of porcine muscle. They've increased the strength of the gels formed by the SSP at temperatures of 70 C to 900 C.

The mixed protein gels, however, were weaker than those formed from the SSP of meat at equal total protein concentrations. Investigators noted no significant differences between the elasticity of meat protein gels and the mixed gels. Mixtures of SSP with soy protein isolate (SPI) produced weaker gels than those mixed with WPC or WPI, while the water-holding capacity of a WPI and SSP mix was greater than that of pure SSP.

The addition of WPC powders to hams increased water-holding capacity and cook yield when phosphates were not included in the brine. WPC powders containing 75% protein were more effective than those containing 35% protein. The addition of beta-lactoglobulin--whey protein--to muscle protein gels decreased gel strength but had no significant effect on the water-holding capacity.

Sensory analysis showed a preference for ham with a flavor described as meaty, hammy and salty. The product had a rough fibrous appearance and a chewy hard texture. Conversely, hams with a processed flavor, a plastic shiny appearance and a rubbery processed texture were disliked. Protein, fat, color, salt and ash content were significantly correlated with hams having positive sensory attributes. High pH and moisture content were significantly correlated with hams having undesirable sensory characteristics.

Scientists also prepared chicken surimi from mechanically separated chicken meat (MSCM) using a series of washing and sieving processes. The chicken surimi contained lower levels of fat, protein, calcium and collagen; had a whiter color than MSCM; and exhibited excellent gel-forming capabilities. From a processing viewpoint, surimi prepared from fresh MSCM forms stronger gels than that prepared from MSCM stored at -180 C for 14 days, irrespective of whether salt was added.

Further information. E. O'Neill, Department of Food Chemistry, University College Cork, County Cork, Ireland; phone: [phone]; fax: [phone].