Characterizing the odor of New Zealand native plants using sensory analysis and gas chromatography-mass spectrometry

There is growing interest by consumers worldwide for edible indigenous plants and wild foods. To highlight and enhance their unique sensory properties, comprehensive sensory characterization is essential to understand and refine their sensory attributes. The aim of this study was to characterize the odor of six edible native New Zealand plants that have significant potential in food applications, using sensory analysis and gas chromatography-mass spectrometry (GC-MS), and uncover the link between annotated volatile compounds and the desirable odor attributes that drive consumer acceptance. A lexicon of 22 odor attributes was developed through six focus groups of six consumers each (n = 36). A Rate All That Apply (RATA) trial was undertaken with consumers (n = 121) to describe the intensity of the odor attributes and overall consumer liking of the odor of each plant. Results showed the characterization of the plant's odor differed significantly across species. Horopito was characterized as "herby," "peppery," "spicy," "minty," and "citrus"; kawakawa was "sour," "sweet," "floral," and "fruity"; pikopiko and kiokio were "earthy/musty," "dry grass/hay," and "fishy"; red matipo was "sweet," "fruity," "sour," "leafy," and "green tea"; and lemonwood was "leafy" and "grassy." Horopito was the most preferred odor by consumers, and pikopiko the least. GC-MS annotated 178 volatile compounds and their peak intensity across the six species. Stepwise regression shortlisted 42 volatile compounds (of which terpenes were the most common) that best explained each of the 22 odor attributes. These results can assist with the application of these native plants as food ingredients.