Saturated Linear Aliphatic γ- and δ-Lactones in Wine: A Review

Abstract

Saturated linear aliphatic lactones are widespread aroma compounds in wine, linked to stone fruit, dried red fruit, and coconut descriptors. Despite their ubiquity, bioproduction pathways associated with these compounds in wine are unclear, but higher concentrations have been linked to many common vitivinicultural practices, including grape variety, microbiological influence, oak-and bottle-aging, and wine styles such as late harvest, noble rot, and icewine. Development of analytical techniques has enabled increasingly accurate quantification of lactones in wine, shedding more light on their potential origins. This review provides an indepth summary of the research into linear aliphatic lactones over the past 50 years and provides direction for possible future research to elucidate the biogenesis of these compounds and better estimate their impact on wine aroma.

A Review on Wine Flavour Profiles Altered by Bottle Aging

“…Lactones are cyclic esters formed from the intramolecular cyclisation of their corresponding hydroxy acid, often associated with coconut or stone fruits, such as peaches or apricots [ 63 , 64 ]. Although the use of oak barrels or chips in wine aging is known to result in the leaching of cis- and trans-whisky lactone into wine, providing coconut/woody aromas [ 63 ], studies have shown that nonalactone increases during wine bottle storage, possibly related to oxygen [ 65 ]. γ-hexalactone and γ-decalactone have been detected in all heated sweet and dry Madeira wines in bottle storage [ 66 ].…”

“…γ-hexalactone and γ-decalactone have been detected in all heated sweet and dry Madeira wines in bottle storage [ 66 ]. The concentration of γ-undecalactone increases during the bottle aging of Chardonnay for one year, which would be promoted by heating the wines, although it is rarely detected and can be misidentified in wine [ 63 , 67 , 68 ]. Nevertheless, some studies have found that lactones are stable during wine bottle storage [ 69 ].…”

Synthesis of a novel isotopically labelled standard for quantification of γ-nonalactone in New Zealand Pinot noir via SIDA-SPE-GC–MS

“…Lactones are common in wine and generally consist of a cyclic ester, formed by intramolecular cyclisation of a corresponding alcohol and carboxylic acid. Saturated linear aliphatic γ-lactones have historically been overlooked as wine aroma compounds [ 2 ]. Coconut, stone fruit, and sweet are among the descriptors attributed to these compounds in wine, and particularly high concentrations have been found in red wines and sweet white wines, such as noble rot wines with the influence of Botrytis cinerea [ 2 - 5 ].…”

“…The route(s) of biogenesis of γ-nonalactone in grapes and/or wine have only been partially elucidated [ 2 ]. Through 18 O-labelling experiments in beer, linoleic acid and its 9- and 13-lipoxygenation products 9-hydroxydecadienoic acid (9-HODE) and 13-hydroxydecadienoic acid (13-HODE) were found to be putative precursors to γ-nonalactone during fermentation (Scheme 1 ) [ 13 ].…”

“…Due to the complex nature of the chiral analysis, most analyses tend to treat these lactones as a racemic mixture [ 2 , 3 , 13 ]. The complexity of the wine matrix means that sophisticated techniques are required for the accurate and precise quantification of specific aroma compounds, particularly those found at low concentrations, including γ-nonalactone.…”