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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Production and Genetic Improvement Research Unit » Research » Publications at this Location » Publication #399605

Research Project: Improved Fruit, Grape and Wine Products through Precision Agriculture and Quality Component Evaluation

Location: Horticultural Crops Production and Genetic Improvement Research Unit

Title: Wine faults in Riesling wine assessed by the electronic tongue

item POTTER, RACHEL - Washington State University
item EDWARDS, CHARLES - Washington State University
item Lee, Jungmin
item ROSS, CAROLYN - Washington State University

Submitted to: Northwest Center for Small Fruit Research Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/10/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Early detection of wine faults is especially important in winemaking to minimize financial and physical losses of wine. A significant source of wine faults in white wines includes spoilage microorganisms within the genera Acetobacter, Wickerhamomyces, Lactobacillus, and Pediococcus. The objective of this study was to track wine fault development in Riesling wine with the electronic tongue (etongue) as compared to sensory evaluation. Bottles of Riesling wine were artificially spiked with 10^4 CFU/mL cultures of A. aceti, W. anomalus, L. brevis, or P. parvalus. Bottles were sealed with screw caps except for A. aceti and a control, which included an additional partially unscrewed cap to allow air flow. Wines were stored at ambient cellar temperature (~13.3°C) for 6 weeks. For detection of wine faults, treatments were assessed weekly with the etongue and a semi-trained rate-all-that-apply (RATA) panel. Panelists were trained to detect aromatic spoilage terms associated with the selected microorganisms and non-spoilage terms associated with Riesling wine. The etongue was capable of detecting differences after week 1 of storage for wines treated with P. parvalus, L. brevis, A aceti (partially unscrewed) and W. anomalus. After 1 week of storage, the discrimination indices produced by the etongue for wines treated with P. parvalus, L. brevis, A aceti (partially unscrewed) and W. anomalus were 96, 94, 98, and 86, respectively. However, over the six-week storage, the etongue did not consistently detect differences in wines treated with A. aceti (sealed). As assessed by the RATA panel, on week 4 of storage, wines treated with W. anomalus had significantly higher intensities of mousy (p = 0.003) and butter aromas (p = 0.002) compared to control wine. On week 6 of storage, wines treated with L. brevis had significantly higher intensities of mousy (p = 0.042) and vinegar/nail polish remover aromas (p = 0.004) compared to control wine. Wines treated with P. parvalus, A. aceti (sealed), and A. aceti (partially unscrewed) did not display significant differences in intensity of aroma spoilage terms over the 6-week storage period. These results showed the etongue to be an effective tool in the early detection of microbial spoilage in Riesling wine by identifying differences prior to RATA panelists detecting differences.