Extended Harvest Date Alter Flavonoid Composition and Chromatic Characteristics of Plavac Mali (Vitis vinifera L.) Grape Berries

Abstract

This study delivers a comprehensive flavonoid fingerprint profile, physiochemical and external color characterization of Plavac Mali grapes through four harvest dates at two distinct vineyards (Split and Zadar) in the Eastern Adriatic region. The experimental harvest lasted 56 days, at total soluble solids content from 18.4 to 22.4°Brix in Split and 16.8 to 20.4°Brix in Zadar. Patterns of 27 skin and seed flavonoid compounds at each location indicate unique flavonoid composition of berries at each harvest date. Extended harvest increased six compounds in skin with maximum values of main anthocyanin malvidin-3-O-glucoside in H3 (4406.6 and 6389.5 mg kg−1, Split and Zadar, respectively) followed by a decrease in October. Peak values of seed and skin catechins and galloylated flavan-3-ol subunits are seen in H1 and H2 at Split, while constantly high values are reported in the case of Zadar, with an incoherent pattern of those in skin extracts. Minimal values of epigallocatechin were detected with an extended harvest date at both locations. Berries of extended harvest dates underwent colorimetric improvements, trough decrease in L*, a*, b* and C characteristics and increase in skin color index for red grapes CIRG. The extended harvest date promotes flavonoid composition, and improves the quality of Plavac Mali grape berries.

Early Defoliation Techniques Enhance Yield Components, Grape and Wine Composition of cv. Trnjak (Vitis vinifera L.) in Dalmatian Hinterland Wine Region

“…Specifically, only preflowering and veraison defoliation led to a significantly higher concentrations of procyanidins, with a predominance of B1 and B3 in wines of T1 treatment, B2, and B4 in T3 treatment. Wine polyphenolic composition depends on berry ripeness [ 43 ], ethanol and wine matrix effect in the disorganization of the outer lipid seed layer [ 42 , 44 ]. In our case, among four different treatments, grapes of T2 reached phenolic maturity, the highest rate of anthocyanins and prodelphinidin units in contrast to procyanidin units in wine [ 41 ].…”

The Evolution of Phenolic Compounds in Vitis vinifera L. Red Berries during Ripening: Analysis and Role on Wine Sensory—A Review

“…A steady decrease in flavan-3-ol monomers throughout ripening was observed in the seeds of Cabernet Sauvignon, Syrah (also known as Shiraz), Pinot Noir and Sangiovese [84,102,106,108]. Moreover, a reduction in the galloylated forms of seed flavanols until the time of harvest has been reported [109][110][111] and, in some cases, also of their mDP [102,106,108,109]. Considering skin flavanols, Kennedy and co-workers [112,113] observed an increase in epigallocatechin percentage during ripening, as well as an increase in their mDP.…”

Evolution of Seed-Soluble and Insoluble Tannins during Grape Berry Maturation

“…), followed by a decline [ 16 ]. The decrease in CT content after véraison is speculated to be due to the formation of oxidative cross-linking products, which strongly bind with the proteins and polysaccharides of cell walls, thus reducing the extractable rate of CT [ 17 ]. However, some studies also indicate no significant evolution of CT content in the seeds during the ripening stage of grapes [ 18 , 19 , 20 ].…”