Potent Odorants in Sweetio Pineapple (Ananas comosus L. Merr. var. Marian-gold (MG3))

Abstract

The potent odorants of the Sweetio pineapple (Ananas comosus [L.] Merr. var. Marian-gold (MG3)) were examined by comparing them with the regular pineapple (Ananas comosus [L.] Merr. var. Smooth Cayenne (F-200)). The odorants in the pineapple extracts, which were pressed from fresh fruit, were separated by adsorption to Porapak Q resin. The total concentration of odorants in Sweetio pineapple extract was approximately twice that of regular pineapple, the upper, middle and lower parts containing higher odorants than their corresponding pars of the regular pineapple. 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol) was found to be the most abundant compound in both pineapples. Sweetio pineapples contained higher proportions of methyl 3-(methylthio) propanoate, 4-methoxy-2,5-dimethyl-3(2H)-furanone (mesifurane), methyl hexanoate, 4-hexanolide, methyl 2-methylbutanoate and ethyl hexanoate than regular pineapples. In addition to these compounds, aroma extract dilution analyses and empirical assessments of odor units revealed that methyl 2-methylbutanoate and ethyl 2-methylbutanoate appeared to be primarily responsible for the characteristic odor of Sweetio pineapples. The enantiomeric ratios of both esters were determined for the first time in this study. Ethyl 2-methylbutanoate was 100% ee for the (S)-(+)-configuration in both pineapples. Methyl 2-methylbutanoate in both regular and Sweetio pineapples were 99.0% ee and 97.4% ee for the (S)-(+)-configuration, respectively. Additive experiments using authentic racemic chemicals revealed that methyl 2-methylbutanoate and ethyl 2-methylbutanoate were the key odorants responsible for the “extending”, “refreshing” and “fruity” notes of the extract, which, on the basis of sensory evaluation, were found to be significantly more intense in Sweetio pineapple extract compared to regular pineapple extract.