Changes in functional properties of vegetables induced by high pressure treatment

Abstract

Ultrahigh-pressure (UHP) hydrostatic exposure in excess of 100 MPa is being used to inactivate micro-organisms as well as to induce texture changes to foods without thermal degradation. The UHP process is said not only to preserve flavour and food product taste but also natural properties of biological products. The influence of high pressure on functional properties of a choice of vegetables was evaluated. The treatments were at pressures around 600 MPa and also in combination with elevated temperatures and in comparison with thermal treatment. Carrots, tomatoes and broccoli were investigated (crushed or liquid extracts). The following characteristics were assessed: content of health promoting substances (e.g. vitamins, antioxidants, antimutagens), effects on water retention, glucose retardation, changes in extractability, in-vitro bioavailability. In most cases high pressure did not induce loss of beneficial substances in the vegetable matrices but induced changes in the structure of the products which resulted in altered physico-chemical properties such as higher glucose retardation index and water retention or reduced extractability.