Electronic Nose Evaluation of Cabernet Sauvignon Fruit Maturity

Abstract

The ability of an electronic nose to classify cabernet sauvignon (Vitis vinifera L.) fruit based on maturity levels was investigated over two seasons. Maturity of samples collected 18, 19, and 20 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 a hand-held electronic nose. The electronic nose was able to determine differences among the three sample groups in both seasons. Additionally, in one season electronic nose measurements were compared to chemical analyses of samples collected from east and west sides of north – south oriented vineyard rows. Results demonstrated the ability of the electronic nose to distinguish fruit from vine canopy sides. Field measurements demonstrated the potential for the electronic nose as a rapid, non-destructive tool for evaluating grape maturity.