Assessing reserve nitrogen at dormancy for predicting spring nitrogen status in Chardonnay grapevines

In this study macro and micro nutrients of plants (N = NH4 + NO3 , P, K, Ca, Na, Zn, Mn, Fe and Cu) were determined both in soil solution and bleeding sap and compared each other. Bleeding sap was collected from the nine varieties of grapevine Cvs. grafted on 5BB rootstock and grown in different soil conditions. For all varieties, plant nutrients content in bleeding sap as higher than in soil solution except for Ca and Na. While in soil solution Ca content was found at 10209 ppm, this value in bleeding sap was 49.20 ppm (Kozak Beyazy), 55.38 ppm (Trakya Ylkeren), 50.37 (Cardinal) and 74.27 ppm (Tekirdaô Çekirdeksizi) respectively. For the same varieties the Na values were as follows : 7.16 ppm (in soil solution) : 4.8, 3.23, 4.21,4.58 ppm (in bleeding sap) respectively. K content in bleeding sap was higher than in soil solution for a few varieties, and lower in some varieties. Traces of Fe and Cu were found in both media.

Recently, the European Commission seems to have inaugurated a new mechanism for regulating the wine sector. Through two communications, articulated in the form of “Questions & Answers”, concerning the new rules for labeling (24.11.2023) and dealcoholization of wine (15.01.2024), the Commission is not simply “explaining” the new rules but, in an approach close to the theory of “Circulaire Normative” established in comparative law, chooses among different interpretations and even adds Praeter Legem constraints.

Sulfur dioxide (SO2) is used in winemaking due of its antioxidant, antioxydasic and antiseptic properties. Excessive amount of SO2 can negatively impact wine sensory perception and be detrimental for health. Agri-food industries are more transparent towards consumers concerning addition of sulfites, and oenology is no exception in this clairvoyance. As a consequence, the increase of consumers preference for wine with low or absent of sulfites addition is notorious. In this context, the impact of low/zero sulfites winemaking process on the microbial community should be evaluated. Moreover, microbial agents corresponding to bioprotective cultures represent a growing interest as an alternative to sulfites preservation in the early stages of vinification. However, scientific studies conducted to demonstrate their real effect are almost rare.

Nowadays, the recovery of secondary resources of wine industry is insufficient and the developing of new products and adjuvants from secondary raw materials could become a relevant sector of research. The re-use of byproducts derived from winemaking could improve the sustainability of wine industry and give additional value to other food industries

The aromatic quality of wines after a long aging period in bottle is one of key points for oenologists. The objective of this work is to determine the main representative aromatic compounds found in long aged wines from D.O.Ca. Rioja. This study was made by 32 wines from 1971 to 2010 vintages. Sotolon, acetaldehyde, phenylacetaldehyde, 1,1,6-trimethyl-1,2-dihydronaptalene (TDN), β-damascenone, Y-decalactone and Y-dodecalactone were determined as the most important oxidation markers by GC-MS analysis. Moreover, sensory analysis using triangular tests were performed from wines with and without the addition of the mentioned compounds. Four different concentrations of each odorant were added, as individual compounds and as mixtures. The additions were ranged from values close to the reference odour thresholds up to high level concentrations. The most identified aroma was sotolon, which is commonly associated to curry and coffee liqueur aromatic notes. Other oxidative compounds were easily detected by panellists, such as Y-decalactone (peach compote), Y-dodecalactone (ripe fruit). The mixtures of the odorants were most easily detected than the individual compounds. It should be noted that acetaldehyde and phenylacetaldehyde were rarely perceived and distinguished.