Microstructural and Enzymatic Contributions to Texture in High Pressure Processed Fruits and Vegetables.

High pressure processing (HPP) is common for beverage treatment, but its application to whole fruits and vegetables is more complex given their susceptibility to tissue softening and noticeable texture changes. Impacts of HPP highly depend on the food material, amount of pressure applied, length of exposure, and synergetic effects with temperature. This paper addresses the effects of HPP parameters (pressure, holding time, and temperature) on physical and chemical attributes, which are responsible for texture in non-beverage fruit and vegetable materials. Nonenzymatic attributes addressed include microstructure and quantitatively measured texture attributes (hardness, displacement distance, springiness, chewiness, cohesiveness, and resilience). Enzymatic attributes addressed include measures of pectin methylesterase activity and polygalacturonase activity, specifically changes to pectin composition and degree of esterification. Other parameters explored include recovery of texture during shelf life, HPP-assisted infusion with calcium and pectin methylesterase for improved texture, and the role of isoenzyme and matrix environment on texture. Based on findings in literature, HPP or combined HPP and thermal treatments has the potential to expand beyond the beverage sector into whole fruit and vegetable products for maintained or improved texture.