Project Number: 6618-41430-005-19
Project Type: Trust

Start Date: Aug 01, 2012
End Date: Jul 31, 2013

Objective:
1. To identify the compounds responsible for off flavors in juice and pulp provided by Coca Cola/Minute Maid. 2. To understand the mechanisms of formation of responsible contaminants by conducting experiments that simulate conditions that are favorable for the development of off-flavors.

Approach:
Samples of defective and normal juice/pulp will be obtained from the industry and analyzed by gas chromatography-olfactometry (GC-O) and a trained sensory evaluation panel. Compounds that are present in the defective juice but not in the normal juice will be identified and quantified using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-pulsed flame photometric detector (GC-PFPD). If warranted by panel evaluations, analysis of non-volatile flavor compounds will also be conducted using liquid chromatography (LC) and liquid chromatography-mass spectrometry (LC-MS). Confirmation of contribution of target compounds to off-flavor will be done by spiking normal orange juice with food grade compound(s) of interest and presented to panelists. Once the compounds that cause off-odor or off-taste are identified and quantified, then experiments will be set up to mimic temperature abuse and/or microbial contamination, and oxidation and the product re-evaluated compared to a control product stored under ideal conditions. This information will be useful to industry to understand which conditions of shipping and storing pulp products result in off-flavors so that these conditions can be avoided, or monitored allowing prediction of product quality. This should result in less product loss due to flavor quality problems, benefitting the industry as a whole.