PhD students develop independent research programs in wine flavor chemistry using advanced mass spectrometry, targeted metabolite extraction, organic synthesis, and sensory-guided validation. Dissertation research spans 4 to 5 years, establishing mechanistic understanding of how environmental factors, viticultural interventions, and fermentation parameters regulate flavor-active metabolite biosynthesis and sensory perception. Students emerge as independent scientists with expertise in analytical chemistry, flavor science, and wine chemistry.
Eligibility & Requirements
- Enrolled or admitted PhD student in the Department of Viticulture & Enology or other departments at UC Davis (Chemistry, Food Science, Agricultural and Environmental Chemistry)
- Strong background in analytical chemistry, organic chemistry, biochemistry, or related disciplines demonstrated through coursework and research experience
- Documented research experience in natural product extraction, chemical analysis, instrumental methods, or related areas (minimum 1 year, typically 2+ years for competitive applicants)
- Demonstrated interest in wine chemistry, flavor science, or food chemistry through research, coursework, or professional experience
- Strong analytical thinking and problem-solving abilities demonstrated through research outcomes
- Excellent written and oral communication skills in English with evidence of scientific writing ability (publications, thesis, technical reports)
- Ability to work independently, manage complex projects, and collaborate effectively in team environments
- External funding through NSF GRFP, Fulbright, USDA, industry fellowships, or other competitive mechanisms strongly preferred but not required for exceptional candidates
Program Timeline
- Typical duration: 4–5 years full-time
- PhD milestones:
- Year 1: Coursework completion, literature review, preliminary data collection, formation of dissertation committee
- Year 2: Qualifying examination, dissertation proposal defense, primary data collection begins
- Year 3-4: Core dissertation research, first-author manuscript preparation and submission, conference presentations
- Year 5: Final data collection, additional manuscript preparation, dissertation writing, oral defense
- Degree requirements:
- Completion of graduate group coursework requirements
- Qualifying examination (oral)
- Dissertation proposal with committee approval
- Minimum 2 first-author publications (submitted or published in peer-reviewed journals)
- Public dissertation seminar and closed committee defense
Financial Support
- PhD students receive full financial support including tuition, fees, health insurance, and competitive stipend.
- Funding mechanisms
- Teaching assistantships: 25–50% appointments in departmental courses, typically 1–2 quarters per year
- Research assistantships: Support through faculty research grants and contracts
- Fellowships: Competitive external fellowships (NSF GRFP, USDA, Fulbright) and internal awards (UC Davis fellowships, Graduate Group support)
- Combined funding: Most students are supported through combinations of TA, RA, and fellowship funding across 5 years
- External fellowship priority
- Students with external competitive fellowships (particularly NSF GRFP) receive priority consideration due to increased research flexibility and enhanced training opportunities.
- Funding guarantee
- Students in good standing receive full funding for 5 years through combination of mechanisms listed above.
Dissertation Research Areas
- PhD students develop independent research programs addressing fundamental questions in wine flavor chemistry.
- Analytical method innovation:
- Development and validation of novel mass spectrometry methods (GC–MS/MS, LC–MS/MS, HRMS) for untargeted and targeted flavor metabolomics
- Advanced sample preparation techniques for complex wine matrices
- High-throughput analytical workflows for large-scale studies
- Integration of multi-dimensional separations with high-resolution mass spectrometry
- Discovery and characterization:
- Identification and structural elucidation of unknown flavor-active compounds through untargeted metabolomics and sensory-guided fractionation
- Biosynthetic pathway elucidation using isotopic labeling and precursor feeding studies
- Structure-activity relationships linking molecular structure to sensory perception
- Mechanistic studies:
- Biochemical mechanisms of flavor compound formation during fermentation, aging, and oxidation
- Enzymatic and non-enzymatic transformation pathways
- Regulation of volatile biosynthesis by yeast genetics, nutrition, and environmental factors
- Temporal dynamics of flavor evolution during production and storage
- Chemical synthesis:
- Organic synthesis of rare flavor-active reference standards unavailable commercially
- Isotopically-labeled internal standards for quantitative analysis
- Synthesis of biosynthetic precursors for pathway elucidation studies
- Predictive modeling:
- Integration of chemical, sensory, and environmental data to predict flavor outcomes from production variables
- Machine learning approaches for metabolite marker discovery
- Chemometric analysis of large-scale datasets
- Climate and environmental chemistry:
- Impact of climate variables (temperature, water stress, smoke exposure) on grape and wine metabolite profiles
- Regional differentiation and terroir chemical signatures
- Mitigation strategies for climate-related quality challenges
Training & Professional Development
- Technical expertise:
- Advanced proficiency in GC–MS/MS, LC–MS/MS, HRMS, and complementary analytical platforms (GC–O, NMR, FTIR)
- Expertise in metabolomics workflows including data acquisition, processing, statistical analysis, and metabolite identification
- Sample preparation and extraction method optimization for complex matrices
- Organic synthesis techniques for reference standard preparation
- Sensory evaluation methodology and psychophysical testing
- Research skills:
- Experimental design for hypothesis testing and mechanistic investigation
- Grant proposal writing (NSF, USDA, fellowship applications)
- Project management for multi-year research programs
- Collaborative research with industry partners and academic institutions
- Mentorship of undergraduate and MS students
- Communication and dissemination:
- Scientific writing for peer-reviewed publication (target: 2–4 first-author papers)
- Oral presentations at regional and national conferences (ASEV, ACS, ASMS, IFT)
- Poster presentations and networking at professional meetings
- Dissertation writing and oral defense
- Public science communication and outreach
- Professional development:
- Direct mentorship from Dr. Chen on research independence, career planning, and professional transitions
- Participation in laboratory management and research group leadership
- Professional society membership and service opportunities
- Teaching experience through TA assignments
- Career Outcomes
- Academic positions
- Tenure-track faculty positions at research universities in analytical chemistry, food science, viticulture/enology, or flavor science departments
- Postdoctoral research positions at leading institutions to develop additional expertise before faculty careers
- Research scientist positions at academic research centers and institutes
- Industry research and development
- Research scientists at wine companies, flavor houses, food and beverage corporations, or ingredient suppliers developing new products and solving technical challenges
- Analytical method developers at contract research organizations or testing laboratories
- Sensory scientists designing and executing consumer research programs
- Analytical instrumentation
- Applications scientists at mass spectrometry manufacturers (Agilent, Waters, Thermo, Bruker, SCIEX) supporting customer research and developing new methodologies
- Technical specialists providing expert consulting and training
- Quality and regulatory
- R&D leaders and quality directors in beverage and food industries
- Technical managers overseeing analytical laboratories and quality systems
- Regulatory affairs specialists in food and beverage sectors
- Academic positions