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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Citrus and Other Subtropical Products Research » Research » Research Project #424029

Research Project: Effect of Nutritional Spray Programs on Huanglongbing (HLB) disease-induced off-flavor of orange fruit and juice.

Location: Citrus and Other Subtropical Products Research

2013 Annual Report

1a. Objectives (from AD-416):
Evaluate juice quality from orange fruit (juice) harvested from groves treated with conventional spray programs compared to groves receiving various nutritional spray programs and determine components of off-flavors.

1b. Approach (from AD-416):
Harvest fruit symptomatic and asymptomatic for Huanglongbing (HLB) disease from trees receiving conventional spray programs and various nutritional spray programs for comparison to healthy fruit/juice, as well as recover oil and determine quality by measuring chemical components along with sensory panels. When off-flavors are detected, determine causal components and establish flavor thresholds for these components using gas-chromatography-mass spectroscopy (GC-MS), electronic nose and tongue, high performance liquid chromatography (HPLC) – MS, and various types of sensory panels.

3. Progress Report:
This project is related to Objective 2 of the in-house project: Relate chemical composition to sensory flavor and pathogen resistance data to determine which compounds are important for flavor or have antimicrobial properties. Two Hamlin and two Valencia harvests were conducted for fruit from healthy and Huanglongbing (HLB) infected trees. Fruit were processed under simulated commercial conditions and samples frozen for sugar, acid, aroma volatiles, bitter limonoids, flavonoids, real time polymerase chain reaction (PCR) for deoxyribonucleaic acid (DNA), and sensory analyses. The chemical, biological and sensory analyses are underway.

4. Accomplishments