Interaction of micellar casein and i-Carrageenan:: Influence of high pressure

The effect of high-pressure treatment (HPT) (up to 950 MPa) on the rheological properties of a mixed system of i-Carrageenan (i-Car) + skim milk powder (SMP), expressed in terms of its micellar casein (MC) content, has been investigated. In the presence and absence of ionic calcium, with or without initial thermal processing, no significant effect has been found on the rheology or gelation/melting temperatures of pure i-Car even under harsh HPT conditions. But, in mixed systems, containing varying amounts of i-Car (up to 1 wt.%) and MC (up to 8 wt.%), substantial changes have been detected. Most significantly, at the higher molar ratios of MC, and particularly at the higher pressures (>400MPa), the dispersions were not thermoreversible in gelation anymore, probably due to the strong interactions of disrupted casein micelles with i-Car molecules, as well as due to the formation of a dominant proteinaceous network.