Volatile and non-volatile profiling of HLB-tolerant mandarins: Identifying superior selections with enhanced fruit quality

Authors: FREITAS, THAIS - Orise Fellow; Mattia, Matthew; Plotto, Anne; Jeffries, Kristen; Rosskopf, Erin; Bai, Jinhe

Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2026
Publication Date: 6/24/2026
Citation: Freitas, T., Mattia, M.R., Plotto, A., Jeffries, K.A., Rosskopf, E.N., Bai, J. Volatile and non-volatile profiling of HLB-tolerant mandarins: Identifying superior selections with enhanced fruit quality. Scientia Horticulturae. 365: 114967. 2026. https://doi.org/10.1016/j.scienta.2026.114967.
DOI: https://doi.org/10.1016/j.scienta.2026.114967

Interpretive Summary: Citrus greening disease continues to severely impact citrus production worldwide, with Florida being one of the hardest-hit areas. To address this problem, the USDA breeding program has been working to develop citrus varieties that can tolerate greening. Mandarins, in particular, have shown promising levels of tolerance. In this study, six mandarin genotypes from the USDA collection were identified as potential new varieties because they performed relatively well under greening pressure in the field. However, to be successful in the marketplace, these mandarins must also offer good eating quality—meaning the fruit should have the right texture, juiciness, sweetness, acidity, color, and easy peeling. The results showed that four hybrids—FF-1-35-72, FF-1-35-25, FF-1-35-96, and FF-1-26-131—had the best overall fruit quality. They contained high sugar levels, low acidity, a balanced sweet-tart flavor, and a pleasant fruity aroma driven by ester compounds. They also had higher carotenoid content, contributing to both nutrition and visual appeal. These qualities make them strong candidates for fresh fruit markets. Hybrid FF-1-21-30 received good consumer liking scores, even though it contained high amounts of the bitter compounds limonin and nomilin. Its high soluble solids may have helped reduce the perception of bitterness. However, its poor peelability and many seeds limit its commercial potential. In contrast, FF-1-21-124 had low sugar content, a wide range of bitter compounds at high levels, and the lowest consumer preference scores. As a result, it appears unsuitable for both fresh eating and processing.

Technical Abstract: The global spread of Huanglongbing (HLB) underscores the need for citrus varieties with disease tolerance and superior fruit quality. Six HLB-tolerant mandarin hybrids were evaluated at optimal maturity alongside commercial controls (‘US Early Pride’ and ‘LB8-9’ Sugar Belle®). Fruit quality, volatile and non-volatile metabolite profiles, together with sensory attributes, were analyzed. Hybrids FF-1-26-131, FF-1-35-96, FF-1-35-72, and FF-1-35-25 exhibited desirable size, color, firmness, peelability, seedlessness, and balanced sugar–acid levels, achieving high sensory ratings. Volatile profiling (36 compounds) revealed distinct clusters, with aldehyde- and ester-rich hybrids (FF-1-35-96, FF-1-35-72) associated with favorable fresh, herbal and fruity aroma attributes. Non-volatile analysis (71 metabolites) indicated FF-1-26-131 closely resembled ‘LB8-9’ Sugar Belle® in sugars and organic acids but differed in carotenoids and limonoids. Positive correlations with overall likability included fruity esters, monoterpenes, sugars, and citric acid, whereas carvone, limonin, and nomilin were negative.