EFFECT OF CHEMICAL MODIFICATIONS ON THE STABILITY, TEXTURE AND MICROSTRUCTURE OF COOKED MEAT BATTERS

The effects of five chemical agents on the stability, texture and microstructure of cooked comminuted meat batters were studied. Beta-mercaptoethanol (beta-ME), hydrogen peroxide (H2O2), ethylenediamine tetraacetic acid (EDTA), urea, and polyoxyethylene sorbitan monooleate (Tween 80) were used. The reduction of disulphide bonds by beta-ME or the oxidation of free sulphydryls by H2O2 prior to cooking did not affect liquid and fat losses during cooking as compared to the control (2.5% NaCl). However, texture profile analysis (TPA) showed that treatment with H2O2 resulted in a harder, more cohesive product than the control and beta-ME treatments because a more fine-stranded, interconnected protein matrix was formed. Treatment of batters with EDTA caused protein matrix aggregation which was accompanied by high liquid losses during cooking (p < 0.05) and resulted in a product with an unacceptable texture. However, EDTA did not cause fat destabilization and most of the fat globules remained surrounded by an intact interfacial protein film (IPF). Urea, which disrupts hydrogen and electrostatic bonds and solubilizes hydrophobic groups, produced extremely stable meat batters with a very cohesive texture. The micrographs of the urea treatment showed that the matrix was formed by a uniform, interconnected, fine-stranded protein network. Batters treated with Tween 80 showed large fat and moisture losses from the cooked product. This was responsible for the soft texture of the batter and corresponded to the very dense aggregates and the lack of an interfacial protein film around the fat globules observed in the micrographs.