Location: Citrus and Other Subtropical Products Research
Project Number: 6034-30600-007-000-D
Project Type: In-House Appropriated
Start Date: Jun 5, 2025
End Date: Jun 4, 2030
Objective:
Objective 1: Establish chemical and sensory quality attributes and identify valuable bioactive compounds for health benefits from citrus, avocado, and new or underutilized crops from subtropical and tropical climates.
Sub-objective 1.A: Develop chemical and sensory attributes for HLB affected/tolerant orange, mandarin, and lemon fruit and processed products.
Sub-objective 1.B: Evaluate avocado genotypes adapted to East-Central Florida conditions for their ripening and storage features as well as healthy bioactive compounds.
Objective 2: Develop value-added products for underutilized crops.
Sub-objective 2.A: Utilize fruits and vegetables low in sugar content, such as winter melon and jicama, to produce low calorie juices.
Sub-objective 2.B: Improve quality of fresh-cut winter melon and jicama.
Objective 3: Establish advanced pre- and postharvest practices to maintain postharvest quality and extend shelf life of new genotypes and new crops using environmental manipulations such as packaging, coatings, and postharvest aqueous treatments.
Sub-objective 3.A: Optimize LED spectral regimes for microgreen as a rapid phenotyping platform to identify photopriming protocols enhancing stress resilience and phytochemical retention.
Sub-objective 3.B: Continuously optimizing ventilation rate, controlled-release natural agent varieties, and release kinetics in active packaging to extend shelf life of microgreens and small/berry fruits while maintaining food safety.
Approach:
Approach:
The research will employ a combination of advanced analytical techniques, sensory science, and practical postharvest technologies to achieve its objectives. The approach is collaborative, data-driven, and aligned with industry needs.
Approach for Objective 1:
• Collaborative Sampling: Close collaboration with USDA breeding programs will provide a continuous supply of HLB-tolerant citrus and new avocado hybrids. Underutilized crops will be sourced from established collections.
• Comprehensive Chemical Analysis: A suite of analytical methods will be employed, including GC-MS for volatile aroma compounds, LC-MS/MS for non-volatile metabolites (limonoids, flavonoids, vitamins, fatty acids), and routine analysis of SSC and TA. DNA will be extracted for CLas titer quantification via qPCR.
• Robust Sensory Evaluation: A trained descriptive panel will profile juices using standardized descriptors. Untrained panels will conduct difference and preference tests for fresh fruit and new products. All testing will use controlled conditions and computerized data collection (Compusense® Cloud).
• Integrated Data Analysis: Chemical and sensory data will be integrated using univariate (ANOVA) and multivariate statistics (PCA, PLS regression). Advanced bioinformatics tools (e.g., WGCNA, KEGG enrichment in R) will correlate data from transcripts, metabolites, and sensory attributes.
Approach for Objective 2:
• Product Development Pipeline: For low-calorie juices, crops will be processed via cold-pressing, enzymatic clarification, and pasteurization. Flavor and nutrient retention will be optimized using techniques like rotary evaporation and resin filtration.
• Fresh-Cut Processing: Cubes of winter melon and jicama will be treated with sanitizers (e.g., peroxyacetic acid), packaged under modified atmospheres, and stored at various temperatures to model shelf-life and quality degradation.
• Staged Industry Engagement: Initial research will focus on proof-of-concept and baseline stability. Upon validation, industry partners (e.g., juice processors) will be engaged for scale-up trials and market-fit analysis.
Approach for Objective 3:
• Controlled Environment Studies: Microgreens will be grown in chambers under different LED spectra. Their metabolic response will be analyzed using LC-MS/MS-based metabolomics to identify light regimes that boost phytochemicals.
• Active Packaging Systems: Novel clamshells with reduced venting will be used to create modified humidity. The controlled release of natural antimicrobials (e.g., thymol encapsulated in a pectin matrix) will be engineered and tested for its efficacy in suppressing decay in berries and microgreens without imparting off-flavors.
• Multi-parameter Quality Assessment: The success of postharvest interventions will be evaluated by monitoring visual quality, firmness, weight loss, incidence of decay, and sensory attributes over defined storage periods.