Evaluation of aroma characteristics in Vitis amurensis grapes across different regions by using HS-SPME-GC/MS

Aim: Evaluating the effects of high amount of air injection during red wine fermentation process, on phenolic extraction dynamics, oxygen dissolution, phenolic compounds evolution, and oxidation of red wines.MethodsRed grapes musts were fermented in 100.000 L stainless steel tank, equipped with Parsec SRL “Air mixing” gas injection systems. For this experiment, treatments with two injection regimes, high and low intensity, and high and low daily frequency, were used. Oxygen analyzer was introduced into the tank to evaluate the gas concentration evolution along the fermentation.

The aim of this ongoing study is to evaluate the degree of adaptability of grapevine scion:rootstock combinations to different conditions of water constraint. Here we present results from the young vine development phase, using three scenarios of water constraint that were implemented from planting. The experimental vineyard was established in 2020 and the data presented will cover the 2021/2022 and 2022/2023 seasons. The experiment consisted of the cultivars Pinotage (PIN), Shiraz (SHI) and Cabernet Sauvignon (CAB), grafted on two rootstocks, Richter 110 (R110) and USVIT-8-7 (US87).

Climate change scenarios suggest an increase in temperatures and an intensification of summer drought. Measuring seasonal plant water status is an essential step in choosing appropriate adaptations to ensure yields and quality of agricultural produce. The water status of grapevines is known to be a key factor for yield, maturity of grapes and wine quality. Several techniques exist to measure the water status of soil and plants, but stem water potential proved to be a simple and precise tool for different plant species.

Climate is the major factor influencing the dynamics of the vegetative cycle and can determine the timing of phenological periods. Knowledge of the phenology of varieties, their chronological duration, and thermal requirements, allows not only for the better management of interventions in the vineyard, but also to predict the varieties’ behaviour in a scenario of climate change, giving the wine producer the possibility of selecting the grape varieties that are best adapted to the climatic conditions of a certain terroir. In 2014, Symington Family Estates, Vinhos, established two grape variety libraries in two different places with distinctive climate conditions (Douro Superior, and Cima Corgo), with the commitment of contributing to a deeper agronomic and oenological understanding of some grape varieties, in hot climate conditions. In these research vineyards are represented local varieties that are important in the regional and national viticulture, but also others that have over time been forgotten — as well as five international reference cultivars. From 2017 to 2021, phenological observations have been made three times a week, following a defined protocol, to determine the average dates of budbreak, flowering and veraison. With the climate data of each location, the thermal requirements of each variety and the chronological duration of each phase have been calculated. During maturation, berry samples have been gathered weekly to study the dynamics of sugar accumulation, between other parameters. The data was analysed applying phenological and sugar accumulation models available in literature. The results obtained show significant differences between the varieties over several parameters, from the chronological duration and thermal requirements to complete the various stages of development, to the differences between the two locations, confirming the influence of the climate on phenology and the stages of maturation, in these specific conditions.

In Portugal, the prospection and conservation of representative samples of intra-varietal variability of grapevine has been carried out for 46 years, and in 2010 an infrastructure was created for the conservation of all these genetic resources – the portuguese association for grapevine diversity (porvid) experimental centre for the conservation of grapevine diversity. the aim is to save the genetic identity of ancient varieties to prevent their imminent loss and to preserve the raw material for current and future selections, thus adding economic value and sustainability to the vine and wine sector.