IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Transition metals and light-dependent reactions: application of a response surface methodology approach

Transition metals and light-dependent reactions: application of a response surface methodology approach


Light-induced reactions can be responsible for detrimental changes of white and rosé wines. This is associated to the photo-degradation of riboflavin (RF) and of methionine (Met) causing the appearance of light-struck taste (LST). The fault is associated to the formation of volatile sulfur compounds (VSCs), namely methanethiol (MeSH) and dimethyl disulfide (DMDS), leading to cooked cabbage, onion and garlic odours-like [1]. Aside these pathways, other oxidative reactions can occur involving iron and copper that can generate quinones. Moreover, the ability of copper in binding the compounds containing a free thiol group is well known. 
This study aimed to evaluate for the first time the combined effect of iron, copper, and oxygen on LST formation in model wine.
A Surface Response Methodology approach was used considering 3 variables, as iron, copper and oxygen. Based on the experimental design, 15 runs (light-exposed and kept in the dark) were performed in model wine. Furthermore, to better understand the influence of phenolics, the same experimental design was applied in the presence of catechin and caffeic acid, used as model phenols. RF, Met, VSCs, and sensory were determined.
No RF was found in any light-exposed sample analysed. The major decrease of Met was revealed in model solution in which MeSH and DMDS were the highest. The presence of phenolics limited the degradation of Met and, consequently, the formation of MeSH and DMDS. In particular, in most of the runs where caffeic acid was added, VSCs were lower than in the runs in model wine and in the presence of catechin. The presence of iron (10 mg/L and 5 mg/L with oxygen 3 mg/L) led to a higher content of mercaptans in model wine as well as in the presence of catechin and caffeic acid. Our findings suggest that besides RF and Met, the susceptibility of a wine in developing LST appeared to be related to the presence of transition metals as well as to the different phenols that would ordinarily be present in wine. 
This study represents a further step for the deeper comprehension of the photo-induced reactions allowing to pursue the LST prevention in white wine.


Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article


Fracassetti Daniela1, Jeffery David2, Ballabio Davide3 and Tirelli Antonio1

1Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Via G. Celoria 2, 20133 Milan, Italy
2Department of Wine Science and Waite Research Institute, The University of Adelaide
3Department of Earth and Environmental Sciences, University of Milano-Bicocca

Contact the author


riboflavin, methionine, catechin, caffeic acid, volatile sulfur compounds


IVAS 2022 | IVES Conference Series


Related articles…

Does wine expertise influence semantic categorization of wine odors?

Aromatic characterization is a key issue to enhance wines knowledge. While several studies argue the importance of wine expertise in the ability of performing odor-related sensory tasks, there is still little attention paid to the influence of expertise on the semantic representation of wine odors.

Overhead spray water treatment as a mitigation strategy for reducing vine stress and preserving grape quality during heatwaves

Changes in climate have been influencing the quality of wine grapes worldwide. The impact of extreme climate events over short periods is increasingly recognized as a serious risk to grape quality and yield quantity. In this study the mitigation effects of a pulsed water spray on vine canopy during heatwave events has been evaluated for maintaining vine condition during the growing season and grape quality. Vines of three varieties (Malbec, Bonarda, and Syrah) under drip irrigation in the UNCuyo experimental vineyard were treated with an overhead pulsed water spray.


Aging red wines in oak barrels is an expensive and laborious process that can only be applied to wines with a certain added value. For this reason, the use of oak alternatives coupled with micro-oxygenation has progressively increased over recent years, because it can reproduce the processes taking place in the barrels more economically and quickly [1]. Several studies have explored how oak alternatives [2-5] can contribute to wine composition and quality but little is known about the influence of their thickness.

qNMR metabolomics a tool for wine authenticity and winemaking processes discrimination

qNMR Metabolomic applied to wine offers many possibilities. The first application that is increasingly being studied is the authentication of wines through environmental factors such as geographical origin, grape variety or vintage (Gougeon et al., 2019).

Alternative fate of varietal thiols in wine: identification, formation, and enantiomeric distribution of novel 1,3-oxathianes

This study aimed to explore an alternative fate of varietal thiols by identifying and characterising cis-2-methyl-4-propyl-1,3-oxathiane