, 1990), and (Z)-3-hexen-1-ol, which imparts a herbal green note ( Jordan et al., 2001), were detected in these samples and described as having green and grass notes, respectively. Eucalyptol, reported by Schieberle et al.
(1990), was another important odorant detected only in mMSL samples. Kemp, Knavel, and Stoltz (1972), and Kemp, Knavel, Stoltz, and Lundin (1974) concluded that (Z)-6-nonenal and 3,6-nonadien-1-ol were two potent odorants contributing to muskmelon flavour. These two compounds were also identified in these samples, having a cucumber and green note, respectively. (Z)-6-Nonenal BMS 754807 was scored consistently higher in the immature fruits, consistent with the greener notes of under-ripe fruit. These compounds were also reported by Pang et
al. (2012) in Jiashi muskmelons and, along with 2,6-nonadienal and 2-nonenal, were the important contributors for green and cucumber-like aromas. Pang et al. (2012) also stated that although esters were superior in concentration (86%), their contribution rate (OAV percentages) to the aroma profile of Jiashi muskmelons was only 10%, whereas alcohols and aldehydes were just the opposite. The contents of aldehydes and alcohols were only 11 and 4% that of esters, respectively, but their contribution rates were 56% and 34% respectively. Finally, of the eight sulphur compounds which were identified in the headspace of the melons, four were detected by the assessors. S-Methyl 2-methylbutanethioate had a sulphury odour, whereas dimethyl trisulfide imparted a pickled onions selleck chemicals and cabbage odour. Ethyl 2-(methylthio)acetate Bay 11-7085 and ethyl 3-(methylthio)propanoate were only identified in mMSL and had an earthy but slightly cucumber note and a cardboard but slightly green odour, respectively. Overall, comparing the odours
between the two maturity stages and the two genotypes, it can be observed that mMSL fruit presented the highest intensities, which resulted in a more aromatic fruit compared to the others. More than 40 compounds were identified in melon SPE extracts and 29 of them were quantified and listed in Table 1. Semi-volatile compounds included 9 esters (acetates and diacetates), 5 sulphur-containing compounds and a few other compounds (alcohols, aldehydes, furans, acids). 2,3-Butanediol diacetate and its precursor 2,3-butanediol monoacetate were identified and found to be significantly higher in mMSL genotype. These compounds were also identified in Japanese melon (cv. Golden Crispy) (Wyllie & Leach, 1990). 2,3-Butanediol diacetate possesses two asymmetric carbons (erythro and threo forms and a meso-form diastereoisomer), thus producing two peaks on GC ( Aubert & Pitrat, 2006). According to Wyllie and Leach, (1990), the most abundant peak would be the D and/or L isomer, whereas the other would be the meso isomer. 1,2-Propanediol and 1,2-ethanediol diacetate were also identified and found to be significantly higher in mMSL genotype.