Multispectral fluorescence sensitivity to acidic and polyphenolic changes in Chardonnay wines – The case study of malolactic fermentation

“The Human being has an excellent ability to detect and discriminate odors but typically has great difficulty in identifying specific odorants”(1). Furthermore, “from a cognitive point of view the mechanism used to judge wines is closer to pattern recognition than descriptive analysis.” Therefore, when one wants to reveal the volatile “wine-like feature” pattern recognition techniques are required. Sensomics is one of the most recent “omics”, i.e. a holistic perspective of a complex system, which deals with the description of substances originated from microorganism metabolism that are “active” to human senses (2). Depicting the relevant volatile fraction in wines has been an ongoing task in recent decades to which several research groups have allocated important resources. The most common strategy has been the “target approach” in order to identify the “key odorants” for a given wine varietal.

Grapevine varieties from South-America, commonly known as criollas, originated because of the natural crossbreeding of grapevine varieties brought by the Spaniards. The objective of this work was to evaluate the potential of some varieties to produce sparkling wines considering the effect of lees contact time. The following varieties were used: Moscatel Rosado, Criolla Chica, Pedro Gimenez, Blanca Oval, Canelón, and the European variety Chardonnay (control), planted in the ampelographic collection of EEA Mendoza INTA (Argentina). Pilot-scale vinifications were carried out to obtain the base wines, in 20 L glass containers. The second fermentation was performed through the traditional method.

Climate change constitutes an enormous challenge for humankind and for all human activities, viticulture not being an exception. Long-term strategic changes are probably needed the most, but growers also need to deal with short-term changes: summers that are getting progressively warmer, earlier harvest dates and higher pH in musts and wines. In the last 10-15 years, a relevant corpus of research is being developed worldwide in order to evaluate to which extent extreme canopy management operations, aimed at reducing leaf area and, thus, limiting the source to sink ratio, could be useful to delay ripening. Although extreme canopy management can result in relevant delays in harvest dates, longer term studies, as well as detailed analysis of their implications on carbohydrate reserves, bud fertility and future yield are desirable before these practices can be recommended.

Umami is defined as a pleasant and savory taste derived from glutamate, inosinate and guanylate, which are naturally present in meat, fish, vegetables and dairy products. The term “kokumi” refers to a complex flavour sensation, characterized by thickness, fullness and continuity.

The phenomenon of quercetin precipitation in wine (flanovol haze), has been manifested for many years in several wine-producing regions