NMR approach for monitoring the photo-degradation of riboflavin and methionine

The Armenian highlands are located on the northern border of western asia and stretch up to the caucasus from the north. Throughout human history, country has played an important role in connecting the civilizations of europe and the near east. The recent large-scale study about the dual domestication origin and evolution of grapes approved that in the Armenian highlands human and grapevine stories are interlaced through centuries and roots of grapevine domestication are found deep in the pleistocene, ending 11.5 thousand years ago. Findings of this study confirmed that glacial episodes distinguish wild grapes into eastern and western ecotypes around 200-400 ka.

Enzymatic browning (BE) of must is caused by polyphenol oxidases (PPOs), tyrosinase and laccase. Both PPOs can oxidize diphenols such as hydroxycinnamic acids (HA) to quinones, which can later polymerize to form melanins [1], which are responsible of BE in white wines and of oxidasic haze in red wines. SO₂ is the main tool used to protect must from BE thanks to its capacity to inhibit PPOs [2]. However, the current trend in winemaking is to reduce and even eliminate this unfriendly additive. Among the different possible alternatives for protecting must against BE, the inoculation with a selected Metschnikowia pulcherrima MP1 is without any doubt one of the most promising ones.

Aims: Viticulture practices linked with soil management, as cover crops and deficit irrigation, can help to regulate the vineyard behavior reducing in most cases plant vigor and modifying plant water and nutrient status, and as a consequence, grape yield and quality. Also, these practices can modify the soil biological activity mostly related to microbiome diversity and functionality.

Valpolicella is a famous Italian wine-producing region. One of its main characteristic is the intensive use of grapes that are submitted to post-harvest withering. This is rather unique in the context of red wine, especially for the production of a dry red wine such as Amarone. Amarone wines produced in Valpolicella different geographic origin are anecdotally believed to be aromatically different, although there is no systematic study addressing the chemical bases of such diversity. Aroma is the product of a biochemical and technological series of steps, resulting from the contribution of different volatile molecules deriving from grapes, fermentations, and reactions linked to aging, as well as one of the most important features in the expression of the geographic identity and sensory uniqueness of a wine.

A good knowledge of the soil physicochemical properties, as well as its ability to retain and put the necessary water available to the plants, is essential when it comes at the design of an irrigation plan.