Sandra C. Diéguez 2003 — Orujo aroma metrics and threshold provenance

Citation And Scope

Diéguez and colleagues (2003), JAFC 51:7385–7390. DOI 10.1021/jf0302916. All six supplied PDF sheets reviewed; Table2 (PDF3) and Table3 (PDF5) visually checked.

Methods And Findings

PDF1–3: solid-phase extraction followed by chromatographic identification and quantification compares compounds in five varietal groups of Galician orujo. Triplicate analyses are technical replication, not independent consumer or product sampling. Varietal associations may include production and storage differences. PDF2–5: threshold-based interpretation identifies candidate aroma contributors including α-ionone, linalool, citronellol and eugenol. The source does not validate these rankings with matched-matrix reconstruction and omission sensory experiments.

Crucial Metric Distinction

Table3 defines contribution as mean concentration divided by 20% of the perception threshold: C/(0.2T), which equals five times C/T. The 20% is a fraction of a threshold, not the alcohol content of the test matrix. For Albariño linalool, C=2.92 mg/L and the cited T=.05 mg/L produce 292 by this index but 58.4 by conventional C/T. Preserve the original metric label; do not merge the 292 into an OAV table. Thresholds in Table1 come from water or wine contexts rather than matched orujo. Their use generates screening hypotheses, not a reliable high-proof flavor prediction. Missing thresholds are unknown, not zero contribution.

Critical Appraisal

The prose says fifteen samples; Table2 visually lists 2+2+2+6+4=16. Retain this unresolved discrepancy rather than silently selecting a count. Unequal small groups and technical replicates restrict generalization. Statements that low concentrations cannot affect aroma are too categorical; mixtures may behave differently. Extraction substitutes α with R in places; chemical identities must be checked against the image before reuse. The reported analytical concentrations and their uncertainty are distinct from perceived intensity, preference and necessity in a mixture.

Blending Lab Application

Any future research data record needs the formula, numerator/denominator, units, threshold matrix, endpoint, source, isomer and uncertainty. Keep concentration, chromatographic signal, FD factor, conventional OAV and this contribution index separate. Use candidates to explain what researchers test next, not to recommend chemical additions or automatically score blends.

Research Connections

Sensory thresholds are properties of a measurement context A validated key-aroma model for American bourbon — Poisson and Schieberle No access