The Impact of Storage Conditions and Bottle Orientation on the Evolution of Phenolic and Volatile Compounds of Vintage Port Wine.

Abstract

This work evaluates the influence of the cellar conditions and bottle orientation, on the phenolic and volatile composition of a Vintage Port wine, sealed with natural cork stoppers, for 44 months post-bottling. The storage was performed in two different cellars, namely a cellar A with controlled temperature and humidity, and a cellar B, representing a traditional cellar, with uncontrolled temperature and humidity. The impact of bottle orientation was studied in cellar A, where the bottles were stored in horizontal and vertical positions. The phenolic and volatile composition of the bottled Vintage Port wine were analyzed after 6, 15 and 44 months. The results unveiled that the cellar conditions and bottle orientation had an impact in Port wine composition which was higher at 44 months post-bottling. The samples stored in the traditional cellar unveiled significantly higher yellow tones, lower tannin specific activity, and higher levels of furfural and 5-methylfurfural. Furthermore, the samples stored in the horizontal position revealed significant higher levels of total proanthocyanidins and higher tannin specific activity than the samples stored in the vertical position. Interestingly, for the first time to our knowledge, an ellagitannin-derived compound (Corklin) was detected in Vintage Port wines stored in the horizontal position, which results from the reaction of cork constituents with phenolic compounds present in wines.