An accurate single-step LLE method using keeper solvent for quantification of trace amounts of sotolon in Port and white table wines by HPLC-DAD.

Affiliation

Milheiro J(1), Vilamarim R(1), Filipe-Ribeiro L(1), Cosme F(2), Nunes FM(3).
Author information:
(1)CQ-VR - Chemistry Research Centre - Vila Real, Food and Wine Chemistry Lab., 5000-801 Vila Real, Portugal.
(2)CQ-VR - Chemistry Research Centre - Vila Real, Food and Wine Chemistry Lab., 5000-801 Vila Real, Portugal; Department of Biology and Environment, University of Trás-os-Montes and Alto Douro, School of Life Sciences and Environment, 5000-801 Vila Real, Portugal.
(3)CQ-VR - Chemistry Research Centre - Vila Real, Food and Wine Chemistry Lab., 5000-801 Vila Real, Portugal; Chemistry Department, University of Trás-os-Montes and Alto Douro, School of Life Sciences and Environment, 5000-801 Vila Real, Portugal. Electronic address: [Email]

Abstract

Sotolon has been reported to play an important role in the typical aroma of aged Port wines. A simple and cheap single-step liquid-liquid extraction (LLE) using glycerol as a keeper for liquid chromatography/ultra-violet absorption quantification of sotolon in Port wines is proposed in this work. The glycerol plays a protective role during the concentration of the extracts increasing the sotolon recovery as well the method repeatability. The proposed method yields chromatograms without interfering compounds and a forty-fold enrichment of sotolon. The detection and quantification limits were far below the sotolon odour threshold in Port wine (19 μg/L). The method was also validated for dry white table wines with good validation parameters. The methodology was successfully applied to selected commercial Tawny, Ruby, and White Port wines, being reported the presence of sotolon in young Ruby and White Port wines for the first time, although below the olfactory detection threshold.