Rheological design of stabilized meat sauces for industrial uses

In the present work a rheological analysis was carried out on sauces produced with a spreadable spicy sausage, typical of the Italian dietary culture, and modified by organogelator addition in order to change their mechanical properties and to solve potential stability issues. From a microstructural point of view, the investigated sauces are suspensions of hard fat/meat phase in a liquid oil solvent based on a mixture of sunflower and olive oil. The stabilization of these heterogeneous systems was carried out by an organogelation technique, thanks to which the solvent was stabilized by a network linking the solid particles. Monoglycerides of fatty acids and policosanol, a fatty alcohol mixture, were used as organogelators at two different fractions (0.1 and 0.5% w/w). Small amplitude oscillation tests and flow tests were carried out, both on fresh samples and on samples destabilized by centrifugation; policosanol was found to be more efficient, even at low concentration, in stabilizing the system, guaranteeing rheological properties similar to those of a benchmark unstable sample, and, in the meantime, giving a good stability to the system subjected to shear stresses (like those arising during mechanical manipulations). Practical applications: Oil suspension stabilization is a relevant challenge in food industry owing to the difficulties in structuring an oil phase. Organogelation is a potential solution to these stability issues because organogelators can structure the oil phase entrapping the dispersed particle in a semi-solid gel network that prevents or delays the separation phenomena. In the present work two different edible organogelators were adopted to stabilize meat suspensions in a vegetable oil mixture, and their effects on both quiescent stability and resistance to mechanical stresses were investigated by using rheological tests. It was shown that organogelation can significantly reduce the separation phenomena between two phases, and it can increase the capacity of materials to bear mechanical loads without affecting the desired consistency. The proposed rheological approach and the adopted organogelators can be used to stabilize also different food suspensions based on liquid oils. The ratio between zero shear viscosity of the destabilized samples and fresh samples as function of the weight loss for: raw material fresh and ground (samples S1 and S2), ground with unstabilized oil phase (sample S3), stabilized with Myverol (sample S4, S5) and with Policosanol (samples S6 and S7).