Profiling of Flavor Volatiles by SPME-GC-MS in Strawberry Cultivars during Fruit Development and Ripening

Strawberry is one of the most important horticultural crops in Korea. However, a thorough understanding of the variations of flavor volatiles in representative cultivars is limited. In this study, four domestic cultivars ('Keumsil', 'Maehyang', 'Sulhyang', and 'Arihyang') and two European wild cultivars (Fragaria vesca 'Yellow Wonder' and F. vesca 'Baron Solemacher') were used to determine flavor volatiles by solid-phase microextraction gas chromatography mass spectrometry in four ripening stages. Among 59 volatiles, methyl isovalerate (CAS No. 556-24-1), hexyl acetate (CAS No. 142-92-7), and hexyl butanoate (CAS No. 2639-63-6) were detected in the 'Sulhyang', 'Maehyang', 'Arihyang' types, respectively. More volatile compounds were present in the pink and red stages compared to the green and white stages in all cultivars. The cultivars 'Keumsil' and 'Arihyang' had relatively high levels of ethyl butanoate (CAS No. 105-54-4) and ethyl hexanoate (CAS No. 123-66-0), compounds with low odor thresholds. The relative levels of ethyl butanoate and ethyl hexanoate in wild strawberry species were approximately 0.9 to 10.3 times higher than those in domestic strawberry cultivars. These results suggest that wild strawberry cultivars are more aromatic than domestic strawberry cultivars. In addition, the findings from a qualitative analysis of the volatile compounds detected in this research could potentially be used as a basis for the future breeding of strawberry fruits with different flavors.