Crossed approaches to experimental economics and sensory analysis regarding noble rot sweet wines perception

I performed my PhD in grapevine physiology under the supervision of Dr. H. Medrano, standing in the vineyards from pre-dawn to sunrise during many hot, wet and sunny days with my colleagues J.M.E. and J.B. I also spent many days and nights facing ticks year-round working in Mediterranean macchias with J.Gu. and M.M. Later I was able to supervise PhD students on grapevines – like A.P. and M.T. – and on Mediterranean vegetation – like J.Gal. With the incorporation to the group of M.R.-C. ‘the puzzle’ was completed and, combining the aforementioned studies, we could conclude (more than 20 years ago) things like: (1) stomatal conductance is the best proxy for ‘water stress’ in studies on photosynthesis; (2) steady-state chlorophyll fluorescence retrieves photosynthesis under saturating light; (3) photoinhibition is not a major photosynthetic limitation under water stress; (4) mesophyll conductance instead is; and (5) mesophyll conductance is a major driver of leaf water use efficiency.

‘Mavrodafni’ (Vitis vinifera L.) is considered one of the oldest grapevine cultivars indigenous to the Greek vineyard, with western Peloponnese being its primary center of cultivation. ‘Renio’ is considered to be either a variant of ‘Mavrodafni’ or an altogether different cultivar. Both ‘Mavrodafni’ and ‘Renio’ can be found in the vineyards of the centers of cultivation, since ‘Renio’ is considered to be more productive compared to ‘Mavrodafni’, and for this reason, it has gradually replaced ‘Mavrodafni’ from cultivation over the course of time. The aim of the present study was to assay the mechanical properties, the polyphenolic content and the antioxidant capacity of skin extracts and must of berries coming from ‘Mavrodafni’ and ‘Renio’, cultivated in the same vineyard as well as in the different regions of cultivation of the PDO Mavrodafni Patras.

Water use efficiency is one of the most valued objectives in vine growing in mediterranean climates (de la fuente et al., 2015). Due to this, the grape growers provide different adaptation strategies according to their efficient consumption against the presumable water deficit generated under these environmental conditions. The use of non-positioned shoot systems (like sprawl, bush, etc.) Can help to achieve this objective.

Red grape pomace, a waste from wine production, can be valorised by extracting polyphenols, high-added value compounds used in cosmetics or oenology. For use at an industrial level, using green extraction techniques, pomace need to be stored before being processed. The aim of this study is to test various storage conditions in order to maintain high level of polyphenols over 180 days, while keeping storage cost economically interesting. In a first step, different storage conditions (ambient temperature or cooled (4°C) temperature, anaerobic (saturation with N2) or aerobic conditions, and addition of sulphur dioxide (SO2)) were compared on small samples (1 kg) packed in plastic pockets. The quality of storage was assessed by following the optical density of the pomace extract at 280 nm (DO 280 expressed as mg/l eq gallic acid), which is an indication of the amount of remaining extractable polyphenols.

La région de la Vallée du São Francisco, situe à 9º S, est en train d’augmenter la production des vins fins les dernières années. La région présente climat du type tropical semi-aride (climat viticole à variabilité intra-annuelle selon le Système CCM Géoviticole : “très chaud, à nuits chaudes et à sécheresse forte à sub-humide” en fonction