INFLUENCE OF CHITOSAN, ABSCISIC ACID AND BENZOTHIADIAZOLE TREATMENTS ON SAVVATIANO (VITIS VINIFERA L.) WINES VOLATILE COMPOSITION PROFILE

Abstract

In the last decades the use of bioestimulants in viticulture have been promoted as alternative to conven- tional pesticides. Moreover, as bioestimulants promote the biosynthesis of secondary metabolites in grape berries, several studies had investigated their influence on the accumulation of phenolic com- pounds (Monteiro et al., 2022). However, few studies, so far, are focused on the accumulation of the vo- latile compounds and their impact on the produced wines (Giménez-Bañón et al., 2022; Gomez- Plaza et al., 2012; Ruiz Garcia et al., 2014).
This study was conducted in a single vineyard of white autochthonous grapevine variety Savvatia- no (Vitis vinifera L.) in Muses Valley (Askri, Viotia, Greece). Chitosan (CHT), Abscisic Acid (ABA) and Benzothiadiazole (BTH) were applied. The applications were performed at veraison stage, in a rando- mized complete block and grapes were harvested at their optimum technological maturity level. White wines vinification procedures were carried out (Miliordos et al., 2022) physiochemical parameters of must and wine, and wine aroma compounds were examined. Volatile compounds were analyzed using a gas chromatography coupled to a mass spectrophotometric detector (Miliordos et al. 2022). Results were statistically evaluated by analysis of variance (ANOVA at the p ≤ 0.05 level) and principal component analysis (PCA). CHT treatment increased total terpenes, esters and monoterpenes concentration which may enhance the desirable aromas for Savvatiano wines. Moreover, ABA enhanced the concentration of total esters, while kept in lower levels higher alcohols than control wines related to unpleasant aromas. On the other hand, BTH kept in low levels monoterpenes and acetates, as well as concentration of acids (hexanoic acid, isobutyric, butyric, isovaleric) and alcohols were still in low levels compared to control wines and the CHT and ABA treated. Furthermore, these differences in the volatile compound levels could sensorially detected, by the sensory panel.
The application of biostimulants recorded promising results to enhance aroma profile of the produced white wines. More research on different Greek cultivars in different terroirs is needed in order to en- hance our knowledge regarding the effect of biostimulants on grape and wine quality. Funding : This research was co-funded by the European Regional Development Fund of theEuropean Union and Greek national funds through the Operational Program ompetitiveness,Entrepreneurship and Innovation, under the call RESEARCH–CREATE–INNOVATE (project code: T1EDK- 04200 (MU-SA).