Selective solubilization of tomato fruit epicuticular wax constituents by Triton X-100 surfactant

The effect of the surfactant Triton X-100, alpha-[4-(1,1,3,3-tetramethylbut yl)phenyl]-omega -hydroxypolyoxy-1,2-ethanediyl, on solubilization of epicu ticular wax of mature tomato (Lycopersicon esculentum Mill.) fruit was inve stigated. The surfactant solubilized the unsaturated hydrocarbons, hexacose ne and tritriacontadiene, and the triterpenols, alpha- and beta -amyrins; s olubilization was concentration dependent above the critical micelle concen tration. Only traces or nondetectable quantities of saturated hydrocarbons were solubilized. Our data provide a definitive evidence that the surfactan t solubilized selective constituents of epicuticular wax. Based on calculat ion of the logarithm of octanol/water partition coefficients for wax consti tuents, it appears that the mechanism of surfactant solubilization of the c onstituents was not solely related to the hydrophobicity of the constituent s, but may involve pi-pi interaction, van der Waals interaction or molecula r conformation of the solubilized constituents. This solubilization of epic uticular wax may decrease the diffusive resistance of the cuticular membran e and, hence, facilitate penetration of surfactant-formulated foliar applie d agrochemicals.