Comparison of tannin analysis by protein precipitation and normal-phase HPLC

Red wine ageing impacts its chemical and sensory characteristics such as colour, astringency and aromas evolution. Wine ageing involves many chemicals and physico-chemical reactions. Oxygen has an important role in these evolutions, especially during bottle ageing. It is known that wine composition and its antioxidant capacity are correlated to its ability to undergo with oxygen exposure [1]. A high oxygen exposure can affect wine quality by the formation of undesirable oxidative volatile compounds such as acetaldehyde [2]. Thus, ageing capacity is an important factor for wine quality and is related to extent of oxidation with ageing [3].

The detection of reducing compounds such as phenolic acids, anthocyanins or tannins is of prime importance to decipher on the antioxidant and anti-aging properties of wines.

Water deficit profoundly impacts the quality of grapes and results in considerable reductions in crop yield. First symptoms manifest with reduced stomatal conductance and transpiration, accompanied by the wilting of apical leaves and tendrils. So far, there is no available data on the water stress response in Croatian grapevine germplasm. Therefore, objective of this study was to determine influence of genotype and treatment on stomatal conductance (gsw), transpiration (E), electron transport rate (ETR), and quantum efficiency in light (PhiPS2).

Developing technologies that help vines survive and produce in quantity and quality within current times is mandatory. In this sense, in the 2021/2022 agricultural harvest, the influence of the foliar application of seaweed – Laminaria japonica was studied, aiming at productivity and quality of the must in the ‘Merlot’ grape. In the city of “Santana do Livramento”, “Rio Grande do Sul” (RS), Brazil; in a 15-year-old commercial vineyard of ‘Merlot’ clone ENTAV-INRA® 347, grafted onto ‘SO4’ rootstock, the following treatments were applied on 6 occasions: No treatment (control) and; Foliar application of Laminaria japonica seaweed (commercial product: Exal (ALAS), 2 kg ha-1).

Context and purpose of the study. Sparkling wine production is majorly impacted by climate change as sugar accumulation and aromatic development in grapes are often decoupled.