Electronic Nose Evaluation of Grape Maturity

Grape maturity is a critical attribute impacting potential wine quality. Maturity evaluation is difficult due to the many interrelated factors that impact physicochemical changes and limitations in the understanding of these factors. Current methods of assessing grape maturity are destructive, expensive, time consuming, subjective, and do not always strongly correlated to potential wine quality. This study evaluated the applicability of a conducting polymer-based electronic nose to monitor grape maturity by analyzing headspace volatiles. In the first part of the study, system and experimental parameters affecting the electronic nose operation were investigated to optimize detection of wine grape aroma. In the second part, the ability of an electronic nose to classify Cabernet Sauvignon (Vitis vinifera L.) grapes based on maturity was investigated. Maturity of samples collected at different weeks post-bloom was evaluated by measuring berry weight, pH, Brix, titratable acidity, total phenols, color intensity, hue, total anthocyanins, and total and phenol-free glycosides. Results were compared, using discriminant and canonical discriminant analysis, with analysis of headspace volatiles via the hand-held electronic nose. The electronic nose was able to determine the difference between the sample groups. Field measurements demonstrated the potential for the electronic nose as a rapid, non-destructive tool for evaluating grape maturity.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Biological Systems Engineering

Department dc:contributor.department

Biological Systems Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2006

Author dc:creator

• Athamneh, Ahmad I.

Chair dc:contributor.committeechair

• Mallikarjunan, Parameswaran Kumar

Committee members dc:contributor.committeemember

• Tu, Zhijian Jake
• Zoecklein, Bruce W.

• electronic nose
• Cabernet Sauvignon
• grape maturity
• grape volatiles
• grape aroma

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-10262006-151209

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/35503