Role of climate on grape characteristics of “Moscato bianco” in Piemonte (Italy)

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.

Mannoproteins are polysaccharides released by Saccharomyces cerevisiae yeast during alcoholic fermentation or by enzymatic action during aging on yeast lees (autolysis). These molecules play a major role in wine characteristics processing, namely, in the tartaric stabilization and protein haze prevention; moreover, they improve color stability and reduce astringency.

The influence of dipping pretreatments on drying of ‘Pedro Ximenez’ grapes, destined to the elaboration of sweet wines, in chamber at controlled temperature, has been studied. Changes in color and phenolic composition of raisins produced were observed during the process of raisining.

Pomace, stem, grapevine leaves, and vine shoots arise as so called winery by-products during the wine production process.

Reactive oxygen species (ROS) play an important physiological role in the body’s defense and being involved in numerous signaling pathways 1, 2. When the balance between oxidant and antioxidant species is altered in favor of ROS, oxidative stress is generated. In this condition the cells are damaged as the ROS oxidize important cellular components, such as proteins, lipids, nucleic acids and