Composition of the surface wax from tomatoes

Abstract

The quantitative composition of the waxes from 26 different tomato cultivars was determined in order to get an overall view of the contents of the compounds identified in Part I at the ripe red stage and of the variability of results. On average, the tomatoes were covered with a wax layer of 50 µg/cm², which resulted in 29% of fraction 1 (mainly long-chain hydrocarbons), in 19% of fraction 2 (mainly long-chain alcohols and triterpenols) and in 52% of fraction 3 (naringenin-chalcone).The contents of a multitude of compounds are presented, most of which occurred only in traces. The predominant components were (in decreasing order) naringenin-chalcone, n-hentriacontane, δ-amyrin, n-nonacosane, β-amyrin, α-amyrin and n-tritriacontadiene, all with mean contents exceeding 2 g/100 g. In addition, the wax composition of one individual tomato cultivar was followed during maturation over the stages green, green-orange, red and mature red. Naringenin-chalcone, alkenes and alkenols were first not present but appeared only during ripening. Although the composition of the wax varied considerably, the triterpenols formed a uniform pattern which was similar for the different tomato cultivars and at all stages of fruit development.