 IVES 9 IVES Conference Series 9 Effect of nitrogen content on fermentation kinetics and aroma profile of assyrtiko wine

Effect of nitrogen content on fermentation kinetics and aroma profile of assyrtiko wine

Abstract

Today, there is need to design, produce and label terroir wines, with unique organoleptic properties and more “attractive to consumers”. For this purpose, two Saccharomyces cerevisiae yeast strains (Sa and Sb) isolated during spontaneous fermentations were used for white wine production from the Assyrtiko grape of Santorini. A third commercial strain was used as control. Two concentrations of Yeast Assimilable Nitrogen (YAN) and DAP (diammonium phosphate) were added to the must (150mg/L and 250mg/L) in order to evaluate the effcet of nitrogen content on the final wine quality. Both analytical chemical methods (HPLC, GC-MS, classical eonological methods) and sensory analysis were employed to assess the chemical composition of the wines and their organoleptic character. In addition fermentation kinetics were monitored throughout the experiment. By the second day of fermentation all three strains had consumed approximately 75% of amino acids. Differences among strains were observed concerning inorganic nitrogen requirements. Sa strain consumed it faster and was the first to compete fermentation independently from the level of added YAN. The commercial strain was characterized by the highest concentration of residual sugars, followed by Sb and Sa. Alcohol content ranged from 12.8-13.1% vol. Sb and the commercial one produced significant higher amounts of glycerol (about 0.7g/L), especially in the case of lower YAN. Sb also produced significant higher amounts of higher alcohols (1.9-fold) and ketones (5.6-fold) but significant lower amounts of esters (1.2-fold) in comparison with the commercial strain. Sa was characterized by significant higher concentrations of fatty acids (2.1-fold) and lower acetic acid (1.6-fold) production. No statistically important differences were observed in the oligomeric phenolic compound content of the samples. Both indigenous strains scored better results in overall aroma quality, and more specifically in “fruity”, “floral” descriptors compared with control. They were also preferred over the commercial strain as far as mouthfeel, body and acidity are concerned. The evaluation of both chemical and sensory data indicated the potential of the indeginous starins for commercial wine production with unique characteristics and high quality.

DOI:

Publication date: September 3, 2021

Issue: Macrowine 2021

Type: Article

Authors

Stefania Christofi, M.Dimopoulou1 Α, Papanikolaou1 G.J, M.Sadoveanu Alley

1 Department of Food Science & Human Nutrition, Laboratory of Oenology, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece, Terpou1 S, Nychas1 C.I., Bogdan2 Romania Academy – Iasi Branch, Research Centre for Oenology, Iasi 700490, Romania V., Cotea3 University of Agricultural Sciences and Veterinary Medicine Iaşi, 3 M. Sadoveanu Alley, Iaşi, 700490, Romania Kallithraka, S1.

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Keywords

aminoacids, fermentation kinetics, saccharomyces cerevisiae, volatile compounds

Citation

VineyardFACE: Investigation of a moderate (+20%) increase of ambient CO2 level on berry ripening dynamics and fruit composition

Climate change and rising atmospheric carbon dioxide concentration is a concern for agriculture, including viticulture. Studies on elevated carbon dioxide have already been on grapevines, mainly taking place in greenhouses using potted plants or using field grown vines under higher CO2 enrichment, i.e. >650 ppm. The VineyardFACE, located at Hochschule Geisenheim University, is an open field Free Air CO2 Enrichment (FACE) experimental set-up designed to study the effects of elevated carbon dioxide using field grown vines (Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon). As the carbon dioxide fumigation started in 2014, the long term effects of elevated carbon dioxide treatment can be investigated on berry ripening parameters and fruit metabolic composition.
The present study aims to investigate the effect on fruit composition under a moderate increase (+20%; eCO2) of carbon dioxide concentration, as predicted for 2050 on both Riesling and Cabernet Sauvignon. Berry composition was determined for primary (sugars, organic acids, amino acids) and secondary metabolites (anthocyanins). Special focus was given on monitoring of berry diameter and ripening rates throughout three growing seasons. Compared to previous results of the early adaptative phase of the vines [1], our results show little effect of eCO2 treatment on primary metabolites composition in berries. However, total anthocyanins concentration in berry skin was lower for eCO2 treatment in 2020, although the ratio between anthocyanins derivatives did not differ.
[1] Wohlfahrt Y., Tittmann S., Schmidt D., Rauhut D., Honermeier B., Stoll M. (2020) The effect of elevated CO2 on berry development and bunch structure of Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon. Applied Science Basel 10: 2486

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Impact of climate change on the viticultural climate of the Protected Designation of Origin “Jumilla” (SE Spain)

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