Impact of crop level and harvest date on anthocyanins and phenolics of red wines from Ontario

Abstract

Cabernet Sauvignon (CS) and Cabernet franc (CF) vines were subjected to two crop levels (full, half) and three harvest dates (earliest to latest; T0, T1, T2) over two vintages. Wines were analyzed for anthocyanins, phenolics, and proanthocyanidins. Crop level increased CS hue (2011-2012), increased CS pH and reduced CS color intensity (2012), and reduced CF hue (2012). Harvest date had a greater effect than crop level, with many treatment interactions. Half crop (2011) increased three CS anthocyanins plus procyanidin B. Extended harvest increased eight compounds. Quercetin and (+)-catechin decreased in T1. Crop reduction (2012) increased malvidin-3coumarylglucoside and (+)-catechin, but decreased petunidin and delphinidin-3-coumarylglucoside. Harvest date (2012) impacted all but two compounds, with the highest anthocyanin concentrations in T1 wines. Gallic acid, (+)-catechin and resveratrol increased with harvest date, while three phenols decreased. Half crop (2011) increased CF peonidin. Extended harvest increased four phenols while three others decreased. Crop reduction (2012) increased delphinidin-3-acetylglucoside, cyanidin-3-coumarylglucoside and caffeic acid; (−)-epicatechin and p-coumaric acid decreased. Several anthocyanins and phenols decreased between T0 and T2, nine of 13 anthocyanins decreased between T0 and T1, while others decreased from T1 to T2. Gallic acid and (+)-catechin increased with harvest date; (−)-epicatechin, p-coumaric acid, quercetin, and resveratrol decreased.

Crop Level and Harvest Date Impact on Four Ontario Wine Grape Cultivars. II. Wine Aroma Compounds and Sensory Analysis

“…Data were collected on: yield components, vine size, berry, must and wine composition (Moreno Luna et al, 2017); winter hardiness and cane carbohydrates (Lefebvre et al, 2015); and individual anthocyanins and phenolics (Black et al, 2016). Wines were produced from each field treatment replicate using standard methods (Reynolds et al, 2007;Di Profio et al, 2011;Moreno Luna et al, 2017).…”

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

“…Although patterns of five anthocyanin monoglucosides increased from H1 to a H4, a peak in main component in Plavac Mali [ 29 , 51 ] malvidin-3- O -glucoside was reached at H3 on both locations with a significant decrease afterwards. On the contrary [ 16 ], an increase in final products of anthocyanin pathway, malvidin- and peonidin-3- O -glucosides, and a decrease in other monoglucoside forms in Cabernet Sauvignon was attributed to an extended harvest date and partly to a late season fungal infections. However, a mismatch in reaching the pattern peak in those compounds due to location is seen in Table 2 .…”

“…Peak in aromatic and flavor complexity, fruity scents and full body, soft tannins wines are associated to phenolic maturity of the grapes [ 5 , 11 , 15 ]. Extended hang time on the vines in certain vintages gives extraordinary quality [ 3 , 13 , 16 ]; however, compromised wine quality potential is reduction of natural acidity, increase in pH, reduction of anthocyanins, shift in color toward violet, reduction in polyphenols and color [ 11 , 17 ] and a prevalence of cooked, jammy and waxy types of aromas and flavors of raisins [ 1 ]. Selecting the optimal time for grape harvesting is an important decision in grape growing and wine making.…”

Timing and severity of crop load management influences technological maturity, terpene synthase expression and free terpene accumulation in Gewürztraminer grapes (Vitis viniferaL.)

“…Crop load management is a practice used by viticulturists to optimise fruit composition in vineyards (Jackson and Lombard 1993, Keller 2015), and involves removing inflorescences or bunches from vine shoots. Reducing the crop per vine, particularly that of an overcropped vine, can increase berry and bunch mass, accelerate ripening, increase the concentration of VOC and phenolic compounds, and promote berry colour (Guidoni et al 2002, Hannam et al 2015, Black et al 2016, Kok 2016). The timing of CLM is also an important factor.…”