Influence of Maturity Stage at Harvest on the Fruit Quality and Volatile Organic Compounds of "Legacy" Blueberry.

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.