Effect of seasonal climate fluctuations on the evolution of glycoconjugates during the ripening period of grapevine cv. Muscat à petits grains blancs berries

Abstract

Considering the three seasons, grapes synthesized and accumulated more precursors when milder temperatures and late rains throughout veraison were recorded. However, we observed a high fluctuation of aroma precursors during the ripening period, so choosing the correct harvesting date (according to grape aroma potential) may overcome some of the negative effects linked to climate conditions. © 2017 Society of Chemical Industry.

The Actual and Potential Aroma of Winemaking Grapes

“…formed very soon, sharp decrease [15,66] Geraniol Always found; up to 10% of total terpenes in Shiraz, 14% in Muscat [144] No [138]; 3-30% of levels found in enzymatic [12] Maxima in fermentation, sharp decrease in aging [14,143]; formed very soon, sharp decrease [15,66] (Z)-Rose oxide 11-29 ppb in Muscat, depending on maturity [145]; unrelated to free form in raisins [23] 0.04 ppb in Muscat, 0.01 ppb in Grenache; not found in Verdejo, Tempranillo, Chardonnay, Cabernet Sauvignon, or Merlot [12] Geranic acid Up to 2-3 ppm [146,147]; also found in raisins [23]; <4 ppb [145]; up to 7.5% total terpenes in Shiraz, 18% in Muscat [144] Not found [138]; 0.5-50% of levels found in enzymatic [12] 1.5 ppb in Chardonnay juices [148] Piperitone Derived from limonene, unknown accumulation pattern [149]; limonene accumulates in the first periods of aging, then slight decrease [66] n.d.: Not detected. Table 7.…”

“…These compounds cannot be determined by harsh acid There are a number of recent reports about the evolution of these precursors during grape maturation. Results show that the patterns of accumulation depend largely on the aroma compound [145], on the variety of grape [147], and on the vintage [146], which makes difficult to extract sound conclusions. In general, it can be said that glycosidic forms tend to increase with maturation following more regular accumulation patterns than free forms, which can show erratic patterns of evolution during maturation.…”

The Microvine, a plant model to study the effect of vine‐shoot extract on the accumulation of glycosylated aroma precursors in grapes

“…The glycosylated aroma precursors were analyzed indirectly by determining their individual volatile aglycones using the method described by Martínez‐Gil et al . and Crespo et al . About 200 g of berries from each treatment were defrosted, crushed in a blender and filtered through a colander before being centrifuged at 4656 g for 20 min at 10 °C.…”

“…The identification/quantification of aglycones released from the aroma glycosidic fraction of Microvine grapes was performed using an Agilent 6890 (Santa Clara, CA, USA) gas chromatograph coupled with a mass spectrometer of the same series, with a quadrupole filter . The unit was equipped with a DB‐Wax fused silica capillary column (30 m length, 0.25 mm id., 0.5 µm phase thickness; J&W Scientific, Santa Clara, CA, USA) connected to the injector via a deactivated silica pre‐column (1 m length, 0.53 mm i.d.…”

IR Thermography from UAVs to Monitor Thermal Anomalies in the Envelopes of Traditional Wine Cellars: Field Test

“…Temperature influences almost every step of wine production, starting with the growing of the grape [1], but is particularly important for several reactions involved in the process of wine maturation [2,3]. Since many of these reactions are physiochemical in nature, they can be accelerated with high temperatures [4,5].…”