Exploratory Analysis of Free and Glycosidically Bound Volatile Compounds in Australian-Grown and Imported Dragon Fruit: Implications for Industry Standard Development

Dragon fruit (Hylocereus spp.), a globally popular tropical fruit, is highly regarded for its unique sensory attributes and potential health benefits. However, the volatile organic compound (VOC) profiles that define its aroma and flavor are underexplored. This exploratory study investigates the VOC profiles of Australian-grown and imported dragon fruit, focusing on free volatiles and glycosidically bound volatiles released through acid and enzymatic hydrolysis. The analysis aims to uncover the competitive advantages of Australian-grown dragon fruit, providing a scientific foundation for establishing industry standards in Australia, where such standards are currently absent. Using gas chromatography–mass spectrometry (GC-MS) and statistical analysis such as principal component analysis (PCA), this study revealed significant differences in VOC profiles influenced by variety and growing region. Northern Territory-grown white-fleshed dragon fruit (NTW) displayed the most diverse and unique volatile profile, with key unique contributors such as acetoin, phenylethyl alcohol, and prenol, highlighting its potential as a premium product. Despite regional similarities, Queensland-grown white- (QLDW) and red-fleshed (QLDR) dragon fruit exhibited distinct profiles, with compounds such as farnesol and linoleic acid ethyl ester serving as distinguishing markers. Overseas white- (OverseasW) and red-fleshed (OverseasR) samples had less complex profiles, likely related to earlier harvesting and postharvest treatments, emphasizing the impact of such practices on volatile complexity. Glycosidically bound volatiles were identified as latent precursors that enhance aroma during ripening and processing. This research underscores the importance of VOC profiling in potentially assisting with establishing industry standards for Australian dragon fruit, enabling the differentiation of domestic varieties from imports and enhancing market competitiveness. As this is a novel and exploratory study, future research should prioritize the identification of unknown compounds and refine methodologies to better understand the dynamic changes in VOCs during storage and ripening. These findings provide valuable insights for optimizing postharvest practices and developing standards that support the Australian dragon fruit industry’s growth and global positioning.