High pressure homogenization versus ultrasound treatment of tomato juice: Effects on stability and in vitro bioaccessibility of carotenoids

The effect of high pressure homogenization (HPH) and ultrasound treatments on the stability and bioaccessibility of tomato juice were investigated. Maximum total lycopene content (777 mu g/100 g) was achieved at pressure of 200 bar after HPH treatment, and severe lycopene degradation (48%) was observed as the pressure increased to 500 bar. Meanwhile, ultrasound increased total lycopene to 921 mu g/100 g fresh weight at power of 400 W. Both HPH and ultrasound treatments changed the bioaccessibility of total lycopene (1.43 folds and 1.76 folds, respectively) and zeta-carotene (1.06 folds and 0.95 folds, respectively). The increase in lycopene bioaccessibility was attributed to the isomerization of all-trans lycopene and cell breakage induced by HPH and ultrasound treatments. Additionally, the antioxidant activities of tomato juice and digesta were slightly influenced by HPH and ultrasound process. The HPH and ultrasound treatments caused significantly difference to the quality of tomato juice and ultrasound treatment could be a promising technology for obtaining tomato juice with higher bioaccessibility and carotenoid content.