Macrowine 2021
IVES 9 IVES Conference Series 9 The influence of initial phenolic content on the outcome of pinot noir wine microoxygenation

The influence of initial phenolic content on the outcome of pinot noir wine microoxygenation

Abstract

Over the years, microoxygenation (MOX) has become a popular vinification technique to improve wine sensory qualities. However, among the impacting factors reported, only one published study (Cano-López et al. 2008) investigated the effects of initial phenolic content on wines undergoing MOX. The present study aims to establish the importance of this factor and specifically on light-coloured Pinot noir wines.Two Pinot noir wines with a low (PN1) and high (PN2) phenolic content were sterile filtered after malolactic fermentation and treated with two oxygen doses (i.e., 0.50 ± 0.08 and 2.17 ± 0.3 ppm/day) for 14 days with temperature control at 15oC. Control treatments had no MOX. Afterwards, the wines were aged for 1 month and followed by addition (100 mg/L) with the end point determined 4 days later.The results highlighted the importance of having high anthocyanin content for Pinot noir wines subjected to MOX on colour development. A higher anthocyanin content significantly increased colour intensity and resistant pigments in association with a greater increase in polymeric pigments. However, it did not guarantee colour stability, and bleaching erased the improvement on colour intensity in all wines.

We speculated that improvement of colour stability by MOX would be dependent on acetaldehyde production, forming pigments with the ethyl-bridged covalent bond that is more resistant to cleavage and bleaching. In this trials, limited acetaldehyde formation would expect after the removal of yeast with sterile filtration. Regarding tannin composition, MOX accelerated the decrease of (-)-epigallocatechin extension units in both PN1 and PN2. In PN1, the higher oxygen dosage led to the higher formation of tannin macromolecules and significantly lower tannin yield and (+)-catechin extension units, increasing the proportion of tannin terminals units.

These could be of concern for astringency perception (Ma et al. 2014). Therefore, MOX should be applied to Pinot noir and other low phenolic wines with caution.

DOI:

Publication date: September 13, 2021

Issue: Macrowine 2021

Type: Article

Authors

Yi Yang (Billy) 

The University of Auckland, New Zealand,Paul A. Kilmartin, The University of Auckland Rebecca C. Deed, The University of Auckland Leandro D. ARAUJO, Lincoln University

Contact the author

Keywords

microoxygenation, initial phenolic content, colour development, tannin composition, pinot noir wine

Citation

Related articles…

Building new temperature indexes for a local understanding of grapevine physiology

Aim: Temperature corresponds to one of the main terroir factors influencing grapevine physiology, primarily evidenced by its impact on phenology. Numerous studies have aimed at expressing time with thermal indices such as growing degree days (GDD) and have thus enabled a better modelling of grapevine responses to temperature. However, some works have highlighted the need to adapt

Effect of ultraviolet B radiation on pathogenic molds of grapes

The fungicidal effect of UV-C radiation (100-280 nm wavelength) is well known, but its applicability for the control of pathogenic molds of grapes is conditioned by its effect on the host and by the risks inherent in its handling[1].
As an alternative, the effect in vitro of UV-B radiation (280-315 nm) on the main pathogenic molds of grapes has been studied: Botrytis cinerea, Aspergillus niger, Penicillium expansum and Rhizopus stolonifer.

Rootstock regulation of scion phenotypes: the relationship between rootstock parentage and petiole mineral concentration

Rootstocks not only provide tolerance to Phylloxera, but also ensure the supply of water and mineral nutrients to the whole plant. Rootstocks are an important way of adapting to environmental conditions while conserving the typical features of scion varieties. We can exploit the large diversity of rootstocks used worldwide to aid this adaptation. The aim of this study was to characterise rootstock regulation of scion mineral status and its relation with scion development.

Modeling the suitability of Pinot Noir in Oregon’s Willamette Valley in a changing climate

Air temperature is the key driver of grapevine phenology and a significant environmental factor impacting yield and quality for a winegrape growing region. In this study the optimal downscaled CMIP5 ensemble for computing thegrowing season average temperature (GST) viticulture climate classification index was determined to spatially compute on a decadal basis predictions of the GST climate index and the grapevine sugar ripeness (GSR) model for Pinot Noir throughout the Willamette Valley (WV) American Viticultural Area (AVA). Forecasts for average temperature and a 220 g/L target sugar concentration level were computed using daily Localized Constructed Analogs (LOCA) downscaled CMIP5 historic and Representative Concentration Pathways (RCP) future climate projections of minimum and maximum daily temperature. We explore spatiotemporal trends of the GST climate classification index and Pinot Noir specific applications of the GSR phenology model for the WV AVA. Spatiotemporal computations of the GST climate index and Pinot Noir specific applications of the GSR model enable the opportunity to explore relationships between their computed values with one intent being to provide updated GST ranges that better align with current temperature-based modeling understanding of Pinot Noir grapevine phenology and the viticultural application of LOCA CMIP5 climate projections for the WV AVA. The Pinot Noir specific applications of the GSR model or the GST index with updated bounds indicate that the percent of the WV AVA area suitable for Pinot Noir production is currently at or near its peak value in the upper 80s to lower 90s of this century.

Aknowledgment and management of vocational units in Chianti Rufina

In Tuscany region the Rufina is a district of Chianti D.O.C.G. positioned in Val di Sieve, 20 km north east from Florence.