Kinetics of Oxidative Degradation of White Wines and How They Are Affected by Selected Technological Parameters

Abstract

The negative effects of oxygen on white wine quality and the various factors which influence it (including temperature, dissolved oxygen, pH, and free SO(2)) are well documented both at the sensory and compositional levels. What is less defined is the quantitative relationship between these parameters and the kinetics of the development of the negative effects of oxidation. The experiment presented here attempts to generate data which can be used to predictively model the oxidative degradation of white wines. Bottled wines were submitted to extreme conditions (45 degrees C temperature, O(2) saturation) during 3 months witth samples taken every 15 days for both sensorial and chemical analysis (GC-O/FPD/MS, 420 nm). The synergistic effects of increasing temperature and O(2) at lower pH are evident, both on the decrease in levels of terpene alcohols and norisoprenoids (which impart floral aromas), and on the development of off-flavors such as "honey-like", "boiled-potato", and "farm-feed" associated with the presence of phenylacetaldehyde, methional, and 1,1,6-trimethyl-1,2-dihydronaphthalene.

The Effect of Micro-oxygenation on the Phenolic Composition, Quality and Aerobic Wine-Spoilage Microorganisms of Different South African Red Wines

“…The addition of SO2 to these samples lowered the perception of the oxidised/aged character slightly. SO 2 binds acetaldehyde, lowering its perception in wine, but it seems that the oxidised aroma of wine is not correlated with the acetaldehyde concentration (Silva Ferreira et al, 2002). The barnyard/medicinal character also increased in the 3 mg O2/L/month treatment between four and six months of treatment.…”

Sauvignon Blanc Wine: Contribution of Ageing and Oxygen on Aromatic and Non-aromatic Compounds and Sensory Composition : A Review

“…A number of trace aroma compounds have been identified as major contributors to these aroma attributes, including various aldehydes, lactones and acetals (Escudero et al, 2000a;2000b;Silva Ferreira et al, 2002b;2003b). The aldehydes are especially important because of their possible impact on wine aromatic composition (Escudero et al, 2000b;Silva Ferreira et al, 2003b;Culleré et al, 2007).…”

“…Aroma attributes that develop due to the formation of new oxidation compounds have been described as honeylike, farmfeed, hay, woody-like, toasted, dry fruits, caramel, overripe fruit, apple, oxidised apple, acetaldehyde, cooked, aldehyde and liquor (Toukis, 1974;Noble et al, 1987;Renouil, 1988;Halliday & Johnson, 1992;Chrisholm et al, 1995;Escudero et al, 2002;Silva Ferreira et al, 2002b). These types of unpleasant descriptors are unwanted in wines, and winemakers go to great lengths to avoid the formation of the chemical compounds responsible for these attributes.…”

Application of an Automated Headspace Solid Phase Micro-Extraction for the GC-MS Detection and Quantification of Reductive Sulfur Compounds in Wines

“…methylglyoxal). This pathway was shown to be the main source of methional in white wines treated with oxygen (Silva Ferreira et al, 2002). Silva Ferreira et al (2003) in a further study did not find that methional was present in a Port wine treated with oxygen, and suggested that the decrease in MTP would lead to the formation of other compounds as yet unidentified.…”