 IVES 9 IVES Conference Series 9 Microwave treatment of grapes: effect on the must and red wine polysaccharide composition

Microwave treatment of grapes: effect on the must and red wine polysaccharide composition

Abstract

AIM: The application of microwaves (MW) to the grape is a technique to reduce the contact time with pomace because it allows to break the cell walls of the berry. The objective of the study was to investigate the changes in the composition of polysaccharides in Cabernet-Sauvignon musts and wines made with grapes treated with microwaves.

METHODS: Red grapes were destemmed and crushed and divided into two batches. One batch was treated with MW at 700 Watts for 12 min and the other batch was not treated to be used as control. Three control microvinifications and three microvinifications treated with MW were carried out, all of them with three days of maceration. The content of each polysaccharide family in the samples was estimated as described by 1 and 2. MW improved the breakdown of cell walls of crushed grapes, thereby it significantly increased the content of polysaccharides rich in arabinose and galactose (PRAG), rhamnogalacturonans-II (RG-II), homogalacturonans (HL) and mannans/mannoproteins (MP) in musts. However, no significant differences were observed between the control and MW wines in the content of PRAG, RG-II, HL and MP.

CONCLUSIONS

MW allowed to increase the release of polysaccharides in must, although its effectiveness was not maintained in wines

DOI:

Publication date: September 7, 2021

Issue: Macrowine 2021

Type: Article

Authors

Belén Ayestarán

Institute of Grapevine and Wine Sciences (ICVV), Logroño, Spain,Leticia, MARTÍNEZ-LAPUENTE, Instituto de Ciencias de la Vid y el Vino (Universidad de La Rioja, Gobierno de La Rioja, CSIC), Finca de La Grajera, Ctra. Burgos 6, 26007 Logroño, Spain Mikel LANDIN, Instituto de Ciencias de la Vid y el Vino (Universidad de La Rioja, Gobierno de La Rioja, CSIC), Finca de La Grajera, Ctra. Burgos 6, 26007 Logroño, Spain Raquel, MUÑOZ GARCÍA, Facultad de Ciencias y Tecnologías Químicas (Universidad de Castilla-La Mancha), Avda. Camilo José Cela, s/n, 13071 Ciudad Real, Spain Zenaida, GUADALUPE, Instituto de Ciencias de la Vid y el Vino (Universidad de La Rioja, Gobierno de La Rioja, CSIC), Finca de La Grajera, Ctra. Burgos 6, 26007 Logroño, Spain

Contact the author

Keywords

microwave, polysaccharides, red must, red wine

Citation

Cluster trait prediction using hyperspectral signatures in a population of 221 Riesling clones

Cluster architecture in grapevine plays a critical role in influencing bunch microclimate, thus quality traits, including sugar content, phenolic composition, and disease susceptibility.

Managing extraction of colour, tannin and methoxypyrazines in Pinot noir grapes treated by leaf removal

Managing extraction of tannins and green aroma compounds attributed from methoxypyrazines in winemaking is crucial for producing high quality Pinot noir wine. This study1 investigated the impact of leaf removal on concentrations of anthocyanins, tannins, and methoxypyrazines in Pinot noir grapes and resultant wines.

Inert gases persistence in wine storage tank blanketing

It is common to find tanks in the winery with wine below their capacity due to wine transfers between tanks of different capacities or the interruption of operations for periods of a few days. This situation implies the existence of an ullage space in the tank with prolonged contact with the wine causing its absorption/oxidation. Oxygen uptake from the air headspace over the wine due to differences in the partial pressure of O2 can be rapid, up to 1.5 mL of O2 per liter of wine in one hour and 100 cm2 of surface area1 and up to saturation after 4 hours.

The film-forming Pichia spp. in a winemaker’s toolbox: A simple isolation procedure and their performance in a mixed-culture fermentation of Vitis vinifera L. cv. Gewürztraminer must

Certain yeast species belonging to the Pichia genus are known to form a distinctive film on grape must and wine. In a mixed-culture type fermentation, Pichia spp. (P. kluyveri in particular) are known to impart beneficial oenological attributes. In this study, we report on an easy isolation method of Pichia spp. from grape must by exploiting their film-forming capacity on media containing 10% ethanol. We isolated and identified two Pichia species, namely Pichia kudriavzevii and Pichia kluyveri, and subsequently co-inoculated them with Saccharomyces cerevisiae to ferment Gewürztraminer musts. Noteworthy differences included a significant increase in the 2-phenethyl acetate levels with the P. kluyveri co-fermentation and a general increase in ethyl esters with the P. kudriavzevii co-fermentation. Both Pichia co-inoculations yielded higher levels of glycerol in the final wines. Based on all the wine parameters we tested, the P. kluyveri strain that was isolated performed similarly to a commercial P. kluyveri strain.

Impact of the maturity and the duration of maceration on phenolic composition and sensorial quality of Divico wines

Following its approval in 2013 by Agroscope, Divico became the first interspecific grape variety in Switzerland with high resistance to downy mildew (Plasmopara viticola) and grey rot (Botrytis cinerea), and medium resistance to powdery mildew (Uncinula nectator). Extremely riche in color, Divico grapes showed great enological potential to different styles of wine. Quickly, many wine growers were interested in planting this promising variety. Many of its potential are to be explored in the coming years.