Multiple spectroscopic approach to elucidate water distribution and water-protein interactions in dry-cured ham after high pressure processing

High Pressure Processing (HPP) influences water-protein interactions inducing sensory changes in dry-cured ham such as an increase in hardness and paleness. The effect of three pressure levels (200, 400 and 600 MPa applied for 5 min) on the water distribution and the protein arrangement of dry-cured ham differing in raw meat pH on Semimembranosus muscle 24 h after slaughtering (pH24SM) was studied using nuclear magnetic resonance relaxometry (NMR), time domain reflectometry (TDR) and multispectral imaging (MI). HPP induced a reallocation of the water populations and a new arrangement of the proteins, particularly between 200 and 400 MPa treatments. The pH of the dry-cured ham affected the distribution of intrinsic water populations, even though samples were similarly affected when subjected to HPP.