Publications by authors named "Andrea Osete-Alcaraz"

4 Publications

  • Page 1 of 1

Revisiting the use of pectinases in enology: A role beyond facilitating phenolic grape extraction.

Food Chem 2021 Oct 1;372:131282. Epub 2021 Oct 1.

Department of Food Science and Technology, Faculty of Veterinary Sciences, University of Murcia, 30100 Murcia, Spain.

With the objective of improving both the extraction of phenolic compounds from grapes and their maintenance in the final wine, we compared the effect of favoring phenolic extraction with a pectolytic-based maceration enzyme with that of favoring both phenolic extraction and the partial elimination of the suspended material using a pectolytic-based clarification enzyme. The phenolic composition of the final wines and those adsorbed to the precipitated lees were analyzed. Both enzymes increased wine color intensity and phenolic content, but the best results were observed when the clarification enzyme was used. This enzyme generated the largest losses of phenolics bound to precipitated lees. However, this resulted in a positive effect, the precipitation of lees rich in phenolic compounds probably created a pronounced gradient of phenolic compounds from grapes to must/wine and better chromatic characteristics in the final wine, compared with the wine made using a traditional maceration enzyme.
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http://dx.doi.org/10.1016/j.foodchem.2021.131282DOI Listing
October 2021

The Influence of Hydrolytic Enzymes on Tannin Adsorption-Desorption onto Grape Cell Walls in a Wine-Like Matrix.

Molecules 2021 Feb 2;26(3). Epub 2021 Feb 2.

Department of Food Science and Technology, Faculty of Veterinary Science, University of Murcia, Campus de Espinardo, 30100 Murcia, Spain.

This study evaluates the capacity of four hydrolytic enzymes to limit the interactions between grape cell-walls and tannins and/or to favor tannin desorption. Adsorption and desorption tests were conducted by mixing a commercial seed tannin with purified skin cell-walls from Syrah grapes, in the presence or absence of hydrolytic enzymes, in a model-wine solution. The effects of the enzymes were evaluated by measuring the tannins in solution by High Performance Liquid Chromatography (HPLC) and the changes in the cell wall polysaccharide network by Comprehensive Microarray Polymer Profiling (COMPP) while the polysaccharides liberated from cell walls were analyzed by Size Exclusion Chromatography (SEC). The results showed that the enzymes limited the interaction between tannins and cell walls, especially cellulase, pectinase and xylanase, an effect associated with the cell wall structural modifications caused by the enzymes, which reduced their capacity to bind tannins. With regards to the tannin desorption process, enzymes did not play a significant role in liberating bound tannins. Those enzymes that showed the highest effect in limiting the adsorption of tannins and in disorganizing the cell wall structure, cellulase and pectinase, did not lead to a desorption of bound tannins, although they still showed a capacity of affecting cell wall structure. The results indicate that enzymes are not able to access those polysaccharides where tannins are bound, thus, they are not a useful tool for desorbing tannins from cell walls. The practical importance implications of these findings are discussed in the manuscript.
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http://dx.doi.org/10.3390/molecules26030770DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7867368PMC
February 2021

The impact of carbohydrate-active enzymes on mediating cell wall polysaccharide-tannin interactions in a wine-like matrix.

Food Res Int 2020 03 14;129:108889. Epub 2019 Dec 14.

Department of Food Science and Technology, Faculty of Veterinary Science, University of Murcia, Campus de Espinardo, 30071 Murcia, Spain.

Tannins are present in grape skins and seeds from where they are transferred into the must-wine matrix during the maceration stages of winemaking. However, tannin transfer is often incomplete. This could be due, among other reasons, to tannins becoming bound to grape cell wall polysaccharides, including soluble polymers, which are released during vinification and are present in high concentrations in the must/wine. The use of cell wall deconstructing enzymes offers the possibility of reducing these interactions, releasing more tannins into the final wine. The main aim of this study was to evaluate the optimal addition (individually, in combination or sequentially) of hydrolytic enzymes that would prevent tight polysaccharide-tannin associations. The use of comprehensive microarray polymer profiling (CoMPP) methodology provided key insights into how the enzyme treatments impacted the grape cell wall matrix and tannin binding. The results demonstrated that polygalacturonase + pectin-lyase promoted the highest release of tannins into solution.
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http://dx.doi.org/10.1016/j.foodres.2019.108889DOI Listing
March 2020

The Role of Soluble Polysaccharides in Tannin-Cell Wall Interactions in Model Solutions and in Wines.

Biomolecules 2019 12 25;10(1). Epub 2019 Dec 25.

Department of Food Science and Technology, Faculty of Veterinary Science, University of Murcia, Campus de Espinardo, 30100 Murcia, Spain.

The interactions between tannins and soluble and insoluble cell wall components are, in part, responsible for the low quantities of tannins found in wines compared with the quantities in grapes. The use of polysaccharides to compete with cell wall components could be an interesting approach for improving the chromatic and sensory characteristics of wines. The effect of two commercial polysaccharides, pectin and mannan, on limiting tannin-cell wall interactions was studied in a model solution, measuring the concentration of tannins and polysaccharides remaining in solution after the different interactions by chromatography. The treatment was also tested in a small-scale vinification. Soluble polysaccharides were added to the must and the wines were evaluated at the end of alcoholic fermentation and after six months in the bottle. In the model solution, the commercial polysaccharides formed soluble complexes with the tannins and limited the interactions with cell wall components, with some differences between skin and seed tannins. In the case of the wines, the treatments resulted in wines with a higher color intensity and phenolic content. Sensory analysis resulted in higher scores for the wines with added polysaccharides, since the complexation of tannins with the polysaccharides increased the roundness and body of the resulting wines.
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http://dx.doi.org/10.3390/biom10010036DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023468PMC
December 2019
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