Rheological and textural characteristics of low-lipid meat emulsions with hydrocolloids as binders

LUCAS MARCHETTI; SILVINA ANDRÉS; ALICIA CALIFANO

Rheology: Theory, properties and practical applications

Nova Publishers

Lugar: Hauppauge; Año: 2012;

There is an increasing interest in improving the nutritional quality of food by means of manipulation of the fatty acid composition. However, replacing solid fats by liquid oils in the batters affects the rheological and textural characteristics of the products. Consequently, additives have to be incorporated to improve these characteristics. Several frequenty used hydrocolloids (hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), a mixture of 2:1 carrageenans (C), and a mixture of 2:1 xanthan-locust bean gums (XL) were selected to compare the effect of a 1 % addition to meat sausages. Two control formulations, one with beef tallow fat and another with fish oil without any binder added were included in the study. The addition of gums compensated for the potential loss of some water binding properties when water was added to the formulation and process yields ranged between 80.9 % and 98.2 %. Texture Profile Analysis (TPA) was performed on chilled (4 °C) sausages, showed a reduction of 40.2% of hardness when solid fat was replaced by fish oil. Addition of xanthan-locust bean gums, or mix of carrageenans gave the highest hardness, similar to fat control while adhesiveness was higher for oil control, MC, and HPMC formulations. Two types of rheological measurements were perfomed, temperature sweeps on raw batter and frequency sweeps of precooked samples. Temperature sweep curves showed a typical behaviour of thermal gelation of meat systems, showing a predominantly elastic behaviour characteristic of weak gels even for the raw batters. As temperature increased bond-making led to structural changes that affected rheological properties increasing elastic moduli and decreasing loss tangent. Cooked batters showed a viscoelastic solids behaviour. The addition of the mixture of carrageenans or xanthan-locust bean gums showed the highest elastic moduli, reflecting the formation of an important three-dimensional network. The viscoelastic behaviour of the cooked systems were modelled according to the broadned Baumgaertel - Schausberger - Winter (BSW) equation, to predict the mechanical relaxation spectra. The plateau moduli (GN0) predicted by the broadened BSW agreed with those calculated directly from dynamic experiments. An empirical superposition method was applied, using the inverse of the plateau moduli GN0 as normalization factors. All data fell into a single master-curve in reasonable approximation which implies that the different additives influenced the level of interactions among macromolecular components.