Effect of climate conditions on the free and glycoside-derived volatile compounds in tomato cultivars

Commercial tomatoes have been increasingly criticized for their declining aroma, driving a search for tomato cultivars with more robust aroma profiles. Volatile organic compounds (VOCs) in tomato fruits play a crucial role in determining their aroma potential. This study investigates tomato cultivars with desirable aroma profiles by examining the levels of free- and glycoside-derived VOCs across 13 cultivars over a three-year period using non-targeted VOC profiling. The analysis detected 41 free VOCs and 35 VOCs released from the glycoside-derived precursors (glycoside-derived VOCs). Principal component analysis of the annotated free and glycoside-derived VOCs revealed that year-to-year differences were more pronounced than cultivar-to-cultivar variations. Among the annotated VOCs, 18 compounds were classified as unique free VOCs, while 12 were unique glycoside-derived VOCs. In 2020, the cultivar Livingstone's stone exhibited significantly higher levels of several key aroma compounds compared to other cultivars and the control, Ailsa Craig. These compounds are known for their low odor thresholds and positive contributions to the overall aroma. These findings suggested that the growth year may substantially influence VOC production in tomato fruits, particularly for specific cultivars or VOCs, likely due to variations in climatic conditions. Consequently, optimizing the release of glycoside-derived VOCs offers a promising strategy to enhance tomato fruit aroma. This approach would be most effective by focusing on key VOCs from specific cultivars, while also accounting for the significant influence of growing year.