Rheology changes in oil-in-water emulsions stabilized by a complex system of animal and vegetable proteins induced by thermal processing

Abstract

Mixtures of animal and vegetable proteins were used to stabilize oil-in-water emulsions of a meat rich filling. Collagen and pea protein, combined in different proportions for a total protein of 9 g/100 g were used to prepare oil-water emulsions, to develop a new meat product. Texture and rheological parameters were measured to evaluate the behavior of the emulsions. Temperature sweeps from 20 to 90 ○C and back (0.5 K/min) were applied and the impact on emulsions structure was monitored, in the rheometer, through the changes on the viscoelastic properties. All the mixtures studied exhibited a shear-thinning flow behavior and showed different viscoelastic properties. The tested systems, exhibited an increase of both viscoelastic moduli on cooling from 90 to 20 ○C, where the storage modulus is always higher than the loss modulus. This increase in viscoelastic functions should result from intermolecular hydrophobic driven cross-linking as well as some hydrogen bonds and physical entanglements between proteins molecules on gel formation induced by the heating/cooling cycles. The 3:1 mixture of collagen and pea protein showed to be a potential formulation for the new meat-product development, as it shows texture values and rheological features according to product specifications