In vitro digestion models have been developed to estimate carotenoid bioavailability but most do not consider that their diffusion from fruit matrix to the lipid phase of the bolus could be a limiting step. Therefore we designed a model in which tomato juice is mixed with oil or oil/water emulsions, and the carotenoids diffusing to oil are measured by spectrometry. Temperature, pH and tomato juice/peanut oil ratio were evaluated for their influence on carotenoid diffusion. When oil/tomato ratio was between 0.11 and 1, extraction of lycopene was limited by the saturation of the oil phase. With a large excess of oil, diffusion was also limited, as only 31 ± 1% of lycopene could be extracted from the juice. Diffusion did not vary significantly with pH but doubled when temperature rose from 10 °C to 37 °C. When the juice was mixed in an emulsion stabilised with bovine serum albumin or phospholipids the maximum extraction decreased to 14.5 ± 0.2% and 18.5 ± 1.5% respectively, indicating that in addition to the saturation of the oil phase at low oil/tomato ratio and in addition to intrinsic properties of the tomato juice in non-saturating conditions, lycopene diffusion was limited by the structure of the interface in emulsions.