Effect of high pressure homogenization (HPH) on the rheological properties of tomato juice: Creep and recovery behaviours

High pressure homogenization (HPH) is a non-thermal technology that has been proposed as a partial or total substitute for the thermal processing of food. Although its effect on microbial inactivation has been widely studied, the rheological changes occurring in fruit products need better describing. The present work evaluated the effect of HPH (up to 150 MPa) on the creep and recovery properties of tomato juice. The mechanical Burger's model explained juice creep compliance well, and its parameters (Newtonian dashpots and Hookean springs) were evaluated as a function of the homogenization pressure. HPH processing increased both tomato juice elastic and viscous behaviours, which could be attributed to the disruption of suspended particles during processing. Moreover, each Burger's model constituent could be related to the product internal structure. The results obtained highlighted the possible applications of the HPH process as a valuable tool to promote physical changes in food products. (C) 2013 Elsevier Ltd. All rights reserved.