Comparison of SPME Versus SAFE Processes for the Analysis of Flavor Compounds in Watermelon Juice

The aim of the study was to compare the extraction efficiency of headspace and solvent extraction methods on watermelon juice flavor. Solid-phase microextraction (SPME) and solvent-assisted flavor evaporation (SAFE) techniques were employed to extract the volatiles from watermelon juice. Aroma compounds were separated and analyzed through gas chromatography-olfactometry-mass spectrometry (GC-MS/O) equipped with DB-5 and DB-Wax capillary columns. Forty-seven compounds were identified by SPME (30) and SAFE (28). These compounds included 7 aldehydes, 10 olefinic aldehydes, 14 alcohols, 7 sulfur compounds, 5 ketones, and 4 miscellaneous compounds. SPME extracted the saturated aldehydes, olefinic aldehydes, alcohols, and ketones effectively, whereas SAFE exerted better efficiency to extract sulfur compounds. (Z,Z)-3,6-Nonadienal, (Z)-6-nonen-1-ol, (E)-2-hexenal, (E)-2-nonenal, hexanal, nonanal, (Z)-3-nonen-1-ol, and (E)-2-octenal were identified as the key aroma compounds through odor activity value (OAV) and aroma extract dilution analysis (AEDA). Also, the aroma compounds can be extracted comprehensively by the combination of both SPME and SAFE techniques.