High pressure homogenization followed by thermal processing of tomato pulp: Influence on microstructure and lycopene in vitro bioaccessibility

High pressure homogenization is a commonly used treatment during the production of tomato based products. The effect on the microstructure and the nutrient quality of tomato products is however poorly documented. Therefore, the aim of this study was to investigate the effect of high pressure homogenization followed by thermal processing on the microstructure, on the lycopene content and on the lycopene in vitro bioaccessibility of tomato pulp. The results showed that increasing the homogenization pressure resulted in the breakdown of the tomato cell aggregate structures, but improved the strength of the fiber network. An inverse relationship between the homogenization pressure, and thus the tomato network strength, and the lycopene in vitro bioaccessibility was noticed. Thermal processing (30 min at 90 °C), subsequent to high pressure homogenization, was not able to sufficiently decrease the strength of the fiber network of homogenized tomato pulp in order to improve the lycopene in vitro bioaccessibility.