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

Abstract

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.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

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

Keywords

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

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Spatial variability of grape berry maturation program at the molecular level 

The application of sensors in viticulture is a fast and efficient method to monitor grapevine vegetative, yield and quality parameters and determine their spatial intra-vineyard variability. Molecular analysis at the gene expression level can further contribute to the understanding of the observed variability by elucidating how pathways responsible for different grape quality traits behave in zones diverging for one or the other parameter. The intra-vineyard variability of a Cabernet Sauvignon vineyard was evaluated by a standard Normalized Difference Vegetation Index (NDVI) mapping approach, employing UAV platform, accompanied by detailed ground-truthing (e.g. vegetative, yield, and berry ripening compositional parameters) that was applied in 14 spots in the vineyard. Berries from different spots were additionally investigated by microarray gene expression analysis, performed at five time points from fruit set to full ripening.

Study of the effect of native vineyard bacteria on the expression of Plasmopara viticolaeffectors

Downy mildew, caused by the oomycete Plasmopara viticola (Berk. & M.A. Curtis) Berl. & De Toni, is one of the most destructive grapevine diseases mostly affecting Vitis vinifera L. and impacting on viticulture. The pathogen invasion can induce in grapevine multiple defense reactions, first PAMP-Triggered Immunity and secondly Effector-Triggered Immunity. Plasmopara viticola can overcome these defense mechanisms through the secretion of effectors, such as RxLR, into the plant cells, making it easier for the oomycete to infect grapevines. Currently, the use of chemical pesticides remains the most effective way to control the pathogen with severe negative side effects on the environment and animal health.

Integrated multiblock data analysis for improved understanding of grape maturity and vineyard site contributions to wine composition and sensory domains

Much research has sought to define the complex contribution of terroir (varieties x site x cultural practices) on wine composition. This investigation applied recent advances in chemometrics to determine relative contributions of vine growth, berry maturity and site mesoclimate to wine composition and sensory profiles of Shiraz and Cabernet Sauvignon for two vintages.

Gastrointestinal digestion of wine sulphites and their effects on human gut microbiota

Sulphites are by far the most widely used additive in the wine industry. In relation to health, the interaction of sulphites with the gut microbiota has not been addressed so far. Following the consumption of wine and other sulphite-containing foods, the gastrointestinal tract and the microbiome are one of the first barriers that these compounds face in the human organism. In this study, we used a previously validated gastrointestinal digestion model (SIMGI®) [1,2] to evaluate the effect of intestinal digestion of wine sulphites on the gut microbiome.

Deciphering the color of rosé wines using polyphenol targeted metabolomics

The color of rosés wines is extremely diverse and a key element in their marketing. It is due to the presence of red anthocyanins extracted from grape skins and pigments formed from them and other wine constituents during wine-making.