Evidence of low-density water to high-density water structural transformation in milk during high-pressure processing

摘要

The objective of this research was to check whether the observed low-density water (LDW) to high-density water (HDW) transformation does take place or not in a complex aqueous system like those involved in high pressure processing of food. In-situ measurements of speed-of-sound up to 640 MPa were used for this purpose. After validation of the methodology in liquid water at 25 degrees C, LDW-to-HDW transformation was also evidenced in sodium caseinate solution and milk samples. The transformation pressure was always observed at 275 MPa. Since water plays a key role in most biochemical transformations, the occurrence of a LDW-HDW transition should be taken into account for understanding the complex component interactions in milk and other related systems under pressure.