Impact of tomato variety and homogenization pressure on in vitro lipid digestion and lycopene bioaccessibility in tomato emulsions

Summary

Tomato-based emulsions (10% w/w rapeseed oil) were prepared from six round and plum varieties differing in lycopene (48–188 mg/kg) and pectin content (385–1098 mg/kg), using blending or high pressure homogenization (HPH) at 20 and 150 MPa. Lipid digestion and lycopene bioaccessibility were assessed using the standardized INFOGEST in vitro digestion model. HPH increased emulsion viscosity and lycopene release into emulsion oil droplets, with release ranging from 6% to 55% depending on variety and pressure. Free fatty acids (FFA) release during intestinal digestion was up to 35% lower than controls without emulsions. Confocal microscopy showed that HPH solubilized pectin, which adsorbed onto oil droplet surfaces and likely hindered lipase activity and micelle formation. Multivariate analysis revealed negative correlations between FFA release and pectin content (r = −0.67), viscosity (r = −0.65), and lycopene in oil droplets (r = −0.78). Despite the enhanced lycopene release by HPH, micellar incorporation remained low (1.5%–3.2%), and micelles were partly entrapped within plant debris, potentially reducing lycopene absorption. These findings demonstrate that lycopene liberation alone does not ensure intestinal bioaccessibility; efficient lipid digestion and micelle formation are critical. Lipid digestion should therefore be considered when evaluating lycopene bioavailability and nutritional quality of tomato-based products.

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DOI : doi.org/10.1002/fob2.70053
NVA : hdl.handle.net/11250/5479911