A review of the current knowledge of red wine colour.

Anthocyanins are the main compounds present in young red wines, being responsible for their intense red colour. These pigments are mainly located in grape skins and their extractability during winemaking depends on many factors, such as their concentration in vacuoles and interaction with the cell-wall polysaccharides, affecting their stability and concentration in the must. The red colour of anthocyanins at wine pH is explained by the stabilization of the flavylium cation form that displays a red colour; otherwise at this pH the hemiketal colourless is the dominant form, bleaching the wine. Besides the contribution of free anthocyanins, a phenomenon called copigmentation influences the colour of young red wines. Copigmentation can be defined as a series of stabilization mechanisms involving van der Walls interactions that occur naturally in red wines and that can explain this unanticipated colour behaviour. Copigmentation is also pointed as the first interaction between anthocyanins and other wine components leading after that to the formation of new coloured compounds during red wine ageing. Some of these pigments have already been identified and characterized but many are still undiscovered. The detection and structural characterization of new pigments, and the knowledge of their chemical formation pathways are crucial to better understand the evolution of the colour of red wine during ageing.

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Quantification and characterization of cell wall polysaccharides released by non-Saccharomyces yeast strains during alcoholic fermentation

International Journal of Food Microbiology ◽

10.1016/j.ijfoodmicro.2012.10.007 ◽

2012 ◽

Vol 160 (2) ◽

pp. 113-118 ◽

Cited By ~ 28

Author(s):

Giovanna Giovani ◽

Iolanda Rosi ◽

Mario Bertuccioli

Keyword(s):

Cell Wall ◽

Alcoholic Fermentation ◽

Cell Wall Polysaccharides ◽

Yeast Strains ◽

Saccharomyces Yeast

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Improved Phenolic Compositions and Sensory Attributes of Red Wines by Saccharomyces cerevisiae Mutant CM8 Overproducing Cell-Wall Mannoproteins

Processes ◽

10.3390/pr8111483 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1483

Author(s):

Phoency F.-H. Lai ◽

Po-Chun Hsu ◽

Bo-Kang Liou ◽

Rupesh D. Divate ◽

Pei-Ming Wang ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Cell Wall ◽

Red Wine ◽

Raw Materials ◽

Principal Component ◽

Consumer Preference ◽

Quality Attributes ◽

Sensory Attributes ◽

Red Wines ◽

High Mannose

The objective of this study was to improve the quality attributes of red wines by Saccharomyces cerevisiae (BCRC 21685) mutant CM8 with overexpression of high-mannose mannoproteins, with respective to phenolic compositions, colorimetric parameters, and consumer sensory attributes. The CM8 was mutated by ethyl methane sulfonate and showed the ability of overproducing cell wall mannoproteins selected by killer-9 toxin-containing YPD plates. Kyoho grapes were used as raw materials. It is interesting to find that the cell wall mannoproteins isolated from CM8 mutant possessed a significantly higher mannose content in the polysaccharide fraction (81% w/w) than that did from parent strain (66% w/w). The red wines made of winter grapes and CM8 (CM8-WIN) showed significantly greater total tannins, flavonols, and anthocyanins levels, as well as higher color, higher flavor, and higher consumer preference than those by its SC counterpart (SC-WIN). The characteristics of the red wines studied were further elucidated by principal component analysis. Conclusively, using CM8 starter could effectively endow the red wine with high-quality attributes via the interactions of high-mannose mannoproteins with wine compounds.

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