Quantification of the aromatic potential of ripe fruit of Vanilla planifolia (Orchidaceae) and several of its closely and distantly related species and hybrids

Vanilla flavor is derived from the cured fruits of two orchid species Vanilla planifolia and V. × tahitensis. About twenty other Vanilla species are also credited with scented fruits, but very little is known about their aromatic features. We investigated the aromatic compound content of the ripe fruits of 30 vanilla accessions obtained from eight species and three hybrids. Glucovanillin plus six phenolic and one anisic aglycones, extracted after enzymatic hydrolysis, were quantified by High-Performance Liquid Chromatography and Ultra-Violet detection. The analysis of the aromatic contents and the principal components showed clear-cut differences in the aromatic content of the species and varieties studied. The total content of aromatic compounds separated the three species most distantly related to V. planifolia, namely V. lindmaniana, V. crenulata and V. imperialis, from the other species notably by the absence of vanillin potential and a very low total aromatic potential (< 0.45% w/w dry matter). A clear gradient was observed between the different genotypes of V. planifolia, in particular for the total aromatic content (range 3.07–5.00% dry weight) and the vanillin potential (1.80–4.58%). Among all the analyzed samples, the greatest vanillin potential was observed in a V. planifolia x V. × tahitensis hybrid (7.46%). Anisyl alcohol was not detected in any of the 13 V. planifolia varieties but was detected in most of its close relatives such as V. sotoarenasii, V. bahiana, V. tahitensis, and V. pompona. Our data evidenced the very contrasting aromatic profiles of vanilla fruits, even among very close genotypes.