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

The gustatory balance of wines relies on sweetness, bitterness and sourness. In dry wines, sweetness does not result from the presence of residual sugar as in sweet wines, but is due to other non-volatile compounds. Such taste-active compounds are released during winemaking, by grapes, yeasts or oak wood and belong numerous chemical families [1]. Beyond this diversity, stereochemistry of molecules can also influence their sensory properties [2]. However, the molecular determinants associated with this taste have only been partially elucidated. Astilbin (2R, 3R) was recently reported to contribute to wine sweetness [3]. As its aglycon contains two stereogenic centers, three other stereoisomers may be present: neoisoastilbin (2S, 3R), isoastilbin (2R, 3S), and neoastilbin (2S, 3S). These compounds have already been observed in natural products, but never in wine. This work aimed at assaying their presence for the first time in wines as well as their taste properties.The isomers were synthesized from astilbin and purified by semi-preparative HPLC.

Following anecdotal evidence of unwanted ‘tropical’ character in red wines resulting from vineyard interventions and a subsequent yeast trial observing higher ‘red fruit’ character correlated with higher thiol concentrations, the role of polyfunctional thiols in commercial Australian red wines was investigated.
First, trials into the known tropical thiol modulation technique of foliar applications of sulfur and urea were conducted in parallel on Chardonnay and Shiraz.1 The Chardonnay wines showed expected results with elevated concentrations of 3-sulfanylhexanol (3-SH) and 3-sulfanylhexyl acetate (3-SHA), whereas the Shiraz wines lacked 3-SHA. Furthermore, the Shiraz wines were described as ‘drain’ (known as ‘reductive’ aroma character) during sensory evaluation although they did not contain thiols traditionally associated with ‘reductive’ thiols (H2S, methanethiol etc.).

Under standard wine tasting conditions, volatile organic compounds (VOCs) responsible for the wine’s bouquet progressively invade the glass headspace above the wine surface. Most of wines being complex water/ethanol mixtures (with typically 10-15 % ethanol by volume), gaseous ethanol is therefore undoubtedly the most abundant VOC in the glass headspace [1]. Yet, gaseous ethanol is known to have a multimodal influence on wine’s perception [2]. Of particular importance to flavor perception is the effect of ethanol on the release of aroma compounds into the headspace of the beverage [1].

Grapevine is one of the crops that may suffer more negative impacts
under climate change, due not only to changes in temperature but also due to water available. Some of the most direct effects of climate variability on grapevines are the changes in the onset and timing of phenology events and changes in the length of the growing season, which may have further effects on grape quality. The aim of this research was to analyze the changes in vine phenology of some red varieties (Tempranillo, Grenache and Carignan) cultivated in Rioja Oriental (Rioja DOCa), under different climate change scenarios.

According to the algorithm “A step back towards the future 4.1C”, (Cargnello,1986a, 1987d, 1988a.b, 1991, 1993, 1994b, 1995, 1999a.e, 2000b, 2007c, 2008a, 2009d, 2013; and according to the principles of “Charter of Sustainable Viticulture BIO‐MetaEthics 4.1CC” of GiESCO (Carbonneau and Cargnello, 2003 2015, 2017), the historical, applied philosophy and productive analysis connected to the innovations and to the “Certification of the Universal Holistic MetaEthical Sustainability 4.1C” “indexed new global production model 4.1C” has always been fundamental, especially for the “Prosecco Territory” and for the “Prosecco Wine” to design and implement their synergistic future “Sustainable and Certificable 4.1CC” according to the principles of the “Charter of Sustainable Viticulture BIO‐MetaEthics 4.1CC” by the GiESCO (Carbonneau and Cargnello, lc, Cargnello et Carbonneau, 2007, 2018), and of the Conegliano Campus 5.1C. (Cargnello, lc). Nowadays, people think that Prosecco is a wine from the Veneto Region (from Conegliano and Valdobbiadene in particular), while it comes from Friuli‐Venezia Giulia Region (in North Eastern Italy, such as Veneto) more precisely from “Prosecco” in the Municipality of Trieste (TS‐Italy), as documented in 1382 and in 1548, when Pier Andrea Mattioli, described “that ancient wine, which is born in Prosecco”, as a wine with the following characteristics “thin, clear, shiny, golden, odorous and pleasant to taste». In 1888 at the “Wine Fair” of Trieste there were the “Sparkling wine Prosecco” by Giovanni Balanc, by Giuseppe Klampferer and that one by Marino Luxa. In the 19th century, many expressed their appreciation for the “Prosecco” of Trieste. In order to implement intra and extra territorial and cross‐border relations, as well as, the “Certification of: Products, Companies, Territory, Bio‐MétaÉthique District 4.1C” of Prosecco, a series of activities and researches were conducted in 8 companies: 5 in the “Territory of Prosecco” (TS) in which the principles of “Charter of Sustainable Viticulture BIO‐MetaEthics 4.1CC” of GiESCO (Carbonneau and Cargnello, lc) have been successfully applied. In particolar: 1‐ new and original “Sustainable 4.1C global production model” developed also to prevent the problems caused by wild boar, roe deer, and birds while safeguarding their “psychophysical wellness”, as well as the “psychophysical wellness 4.1C” of the macro and micro flora and fauna, of the biodiversity, of the landscape, etc. (Cargnello, lc), 1.2‐ chemical weed control and “Non MetaEthics 4.1C” processing with the total grass growing of the ground without or with mowing, better if it is manual to protect grass, air and soil, 2‐ recovery of “Historic”: land, vineyards, vines, biodiversity, landscapes, productions, products, … , 3‐ production of the famous “Prosekar, also rosé, of Prosecco” and “Prosecco di Prosecco”, according to “A step back towards the future 4.1C” 4‐ to offer a deserved psychophysical well‐being to the “Prosecco Territory” and entrepreneurs.