Abstract
This study systematically investigated the physicochemical properties and aroma dynamics of highbush blueberry (Vaccinium corymbosum "Legacy") across five maturity stages (I: green to V: dark blue) using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The fruit diameter, fresh fruit weight, soluble solids content, soluble sugars, and vitamin C content of these blueberries were found to increase significantly with maturation, whereas the firmness and titratable acidity decreased. Seventy-seven volatile organic compounds (VOCs), predominantly consisting of aldehydes (59.09%-85.18%) and alcohols, were identified. The diversity of VOCs decreased from 65 in Maturity Stage I to 38 in Maturity Stage V, although aldehydes such as (E)-2-hexenal (which peaked at 1292.81 μg/kg in Maturity Stage I) remained consistently present across the maturation stages. Orthogonal partial least squares discrimination analysis identified 10 differential volatile metabolites, including (E)-2-hexenal and hexanal, that distinguished between maturity stages. Odor activity values revealed 17 key aroma contributors, notably hexanal (floral), β-myrcene (peppery), and (E)-2-hexenal (green). Fruits at Maturity Stage IV exhibited the most intense aroma and optimal quality, characterized by their light blue peel, high soluble solids content (14.66%), balanced acidity (0.615%), and rich fruity notes. These findings establish distinct volatile signatures for each maturity stage and serve as objective biochemical markers to optimize harvest timing in blueberry cultivation. Furthermore, these stage-specific profiles provide a scientific basis for raw material grading in product processing, guiding the targeted selection of fruits for fresh market distribution or specific processed products such as juices and fermented wines.