Microstructural behaviour and gelling characteristics of myosystem protein gels interacting with hydrocolloids

Hydrocolloids were added to blue whiting mince in order to study their distribution in the gel and obtain more information about how these additives act on gel characteristics. The addition of hydrocolloid in powder significantly reduced puncture test properties with respect to the hydrocolloid-free gels, except in the case of locust bean gum. On the other hand, compression properties were altered to a greater or lesser extent in gels containing anionic hydrocolloids. Light microscopy revealed that the hydrocolloids expanded as inclusions, forming cavities of varying morphology and size. The anionic hydrocolloids were mixed throughout the protein matrix, probably through interaction with the myofibrillar protein. The non-ionic hydrocolloids were dispersed throughout the matrix but did not interact with it and were located simply by inclusion. The thickening hydrocolloids (locust bean gum, guar gum, xanthan gum, carboxymethylcellulose and alginate) formed a mesh of filaments inside the cavities; while the gelling hydrocolloids (carrageenans) that were mainly inside the cavity interiors formed a continuous structure.