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Determination of ortho- and retronasal detection thresholds for 2-isopropyl-3-methoxypyrazine in wine.
J Food Sci. 2007 Sep; 72(7):S468-72.JF

Abstract

2-Isopropyl-3-methoxypyrazine (IPMP) is a grape-derived component of wine flavor in some wine varieties as well as the causal compound of the off-flavor known as ladybug taint (LBT), which occurs when Harmonia axyridis beetles are incorporated with the grapes during juice and wine processing. The main objective of this study was to obtain robust estimates of the orthonasal (ON) and retronasal (RN) detection thresholds (DTs) for IPMP in wines of differing styles. The ASTM E679 ascending forced choice method of limits was used to determine DTs for 47 individuals in 3 different wines--Chardonnay, Gewürztraminer, and a red wine blend of Baco Noir and Marechel Foch. The group best estimate thresholds (BETs) obtained for IPMP (ng/L) were Chardonnay, ON: 0.32; Gewürztraminer, ON: 1.56, RN: 1.15, and red wine blend, ON: 1.03, RN: 2.29. A large variation in individual DTs was observed. Familiarity with LBT was inversely correlated with DTs for Gewürztraminer, and no difference in thresholds was observed between winemakers and nonwinemakers. We conclude that the human DT for IPMP is extremely low and influenced significantly by wine style and evaluation mode. We recommend against the reporting of single-threshold values for wine flavor compounds, and encourage the determination of consumer rejection thresholds for IPMP in wine.

Authors+Show Affiliations

Dept. of Biological Sciences, Brock Univ., 500 Glenridge Ave., St. Catharines, ON L2S 3A1, Canada. gary.pickering@brocku.caNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17995659

Citation

Pickering, G J., et al. "Determination of Ortho- and Retronasal Detection Thresholds for 2-isopropyl-3-methoxypyrazine in Wine." Journal of Food Science, vol. 72, no. 7, 2007, pp. S468-72.
Pickering GJ, Karthik A, Inglis D, et al. Determination of ortho- and retronasal detection thresholds for 2-isopropyl-3-methoxypyrazine in wine. J Food Sci. 2007;72(7):S468-72.
Pickering, G. J., Karthik, A., Inglis, D., Sears, M., & Ker, K. (2007). Determination of ortho- and retronasal detection thresholds for 2-isopropyl-3-methoxypyrazine in wine. Journal of Food Science, 72(7), S468-72.
Pickering GJ, et al. Determination of Ortho- and Retronasal Detection Thresholds for 2-isopropyl-3-methoxypyrazine in Wine. J Food Sci. 2007;72(7):S468-72. PubMed PMID: 17995659.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Determination of ortho- and retronasal detection thresholds for 2-isopropyl-3-methoxypyrazine in wine. AU - Pickering,G J, AU - Karthik,A, AU - Inglis,D, AU - Sears,M, AU - Ker,K, PY - 2007/11/13/pubmed PY - 2008/1/26/medline PY - 2007/11/13/entrez SP - S468 EP - 72 JF - Journal of food science JO - J Food Sci VL - 72 IS - 7 N2 - 2-Isopropyl-3-methoxypyrazine (IPMP) is a grape-derived component of wine flavor in some wine varieties as well as the causal compound of the off-flavor known as ladybug taint (LBT), which occurs when Harmonia axyridis beetles are incorporated with the grapes during juice and wine processing. The main objective of this study was to obtain robust estimates of the orthonasal (ON) and retronasal (RN) detection thresholds (DTs) for IPMP in wines of differing styles. The ASTM E679 ascending forced choice method of limits was used to determine DTs for 47 individuals in 3 different wines--Chardonnay, Gewürztraminer, and a red wine blend of Baco Noir and Marechel Foch. The group best estimate thresholds (BETs) obtained for IPMP (ng/L) were Chardonnay, ON: 0.32; Gewürztraminer, ON: 1.56, RN: 1.15, and red wine blend, ON: 1.03, RN: 2.29. A large variation in individual DTs was observed. Familiarity with LBT was inversely correlated with DTs for Gewürztraminer, and no difference in thresholds was observed between winemakers and nonwinemakers. We conclude that the human DT for IPMP is extremely low and influenced significantly by wine style and evaluation mode. We recommend against the reporting of single-threshold values for wine flavor compounds, and encourage the determination of consumer rejection thresholds for IPMP in wine. SN - 1750-3841 UR - https://www.unboundmedicine.com/medline/citation/17995659/Determination_of_ortho__and_retronasal_detection_thresholds_for_2_isopropyl_3_methoxypyrazine_in_wine_ DB - PRIME DP - Unbound Medicine ER -