Volatile Aroma and Antioxidant Quality of ‘Shiraz’ Grapes at Different Stages of Ripening

Berry Shriveling Significantly Alters Shiraz (Vitis vinifera L.) Grape and Wine Chemical Composition

“…Lower total polyphenols in Shiraz and Cabernet Sauvignon grapes affected by berry shriveling have been reported, however the trend for total oligomeric proanthocyanidins was not so clear. 12,11 Wine Volatiles. Ethyl Esters of Fatty Acids.…”

“…13 Indeed, late season berry dehydration is well reported to occur in Shiraz vineyards in late ripening, resulting in increased TSS concentrations and yield losses. 1,11,13 Furthermore, also bunch stem necrosis, occurring late in the season can result in TSS concentrations comparable with unaffected controls, and subsequent shriveling can result in higher TSS concentrations. 13 Tartaric and malic acid concentrations and pH were influenced by harvest date and to a lesser extent by berry shriveling.…”

“…Reduction in total grape anthocyanins in Shiraz, Cabernet Sauvignon, and Zweigelt with berry shriveling at harvest was previously observed. 11,12,40 The latter authors 40 have shown the reduction of anthocyanin accumulation in grapes affected by SAD when compared to unaffected grapes. Several studies have reported close, but indirect, correlation between anthocyanins and sugar accumulation during the phase of rapid sugar accumulation into the berry.…”

“…9,10 Berry shriveling can occur, before (already at bloom affecting the ovaries) or after veraison in red and white varieties such as Cabernet Sauvignon, Zweigelt, Barbera, Grenache, Semillion, Sauvignon Blanc, Shiraz, and other cultivars. 10−12 Four types of berry shriveling are reported in the literature, however the etiologies are not well characterized; (i) sun burn either before or after veraison, resulting in poor color development in red varieties and raisin formation in severe occasions, 13 (ii) late season fruit dehydration, characterized by an increase in total soluble solids (TSS) concentration, 11,13 (iii) bunchstem necrosis characterized by necrotic rachis tissue affecting entire clusters or often only bunch shoulders and tips, 13,14 and (iv) sugar accumulation disorder (SAD) resulting in soft, irregular-shaped berries, with low fresh weight, reduced anthocyanins and sugar accumulation. 2,13,15−17 Early bunch stem necrosis can occur at bloom, whereas late season bunch stem necrosis appears after veraison and, depending on the occurrence, grape composition is differentially impacted.…”

“…11,13 Recently carried out work suggested that Shiraz berry shriveling negatively impacted grape anthocyanin concentrations, total terpenoids, alcohols, hydrocarbons, and radical scavenging capacity of grapes. 11 Another study demonstrated an increase in basic juice constituents such as TSS and total acidity in Cabernet Sauvignon shriveled berries, whereas severely shriveled berries had the lowest antioxidant activity, total monomeric anthocyanins and total flavanols. 12 To the authors' knowledge, there are no reports in the literature that describe the impact of berry shriveling on Shiraz wine composition.…”