Influence of Berry Ripening Stages over Phenolics and Volatile Compounds in Aged Aglianico Wine

Alessandro Genovese,Maria Tiziana Lisanti,Lucia Lecce,Simona Antonella Lamorte,Daniela Strollo,Giandomenico Corrado,Boris Basile,Luigi Moio,Angelita Gambuti

doi:10.3390/horticulturae7070184

Abstract

The harvest time of grapes is a major determinant of berry composition and of the wine quality, and it is usually established through empirical testing of main biochemical parameters of the berry. In this work, we studied how the ripening stage of Aglianico grapes modulates key secondary metabolites of wines, phenolics and volatile compounds. Specifically, we analyzed and compared four berry ripening stages corresponding to total soluble solids of 18, 20, 22, and 25 °Brix and related aged wines. Wine color intensity, anthocyanins level and total trans-resveratrol (free + glycosidic form) increased with grape maturity degree. Wines obtained from late-harvested grapes significantly differed from the others for a higher content of aliphatic alcohols, esters, acetates, α-terpineol and benzyl alcohol. The content of glycosidic terpene compounds, such as nerol, geraniol and α-terpineol, was higher in wines obtained with grapes harvested at 25 °Brix compared to the earlier harvests. Our work indicated that the maturity of the grape is a determining factor in phenolic and volatile compounds of red Aglianico wines. Moreover, extending grape ripening to a sugar concentration higher than 22 °Brix improves the biochemical profile of aged wine in terms of aroma compounds and of phytochemicals with known health-related benefits.

Highlights

Wine quality largely depends on identifying the optimal maturity of the grapes at harvest
We studied chromatic characteristics, anthocyanins, tannins, catechin, epicatechin, quercetin, trans-resveratrol, trans-polydatin content and free and bound volatiles of aged wines obtained with grapes harvested at four stages according to the soluble sugar content of the berries
This study demonstrated that the choice of the ripening stage when harvesting the grapes is a crucial decision that will be reflected in the phenolic and aromatic composition of Aglianico wines after 20 months of aging in bottles

Summary

Introduction

Wine quality largely depends on identifying the optimal maturity of the grapes at harvest. Berry weight, sugars, pH, and acidity are traditionally monitored to choose the best moment for harvest. These parameters are often measured to empirically define the technological maturity of the grapes. Grape phenolics are responsible for color, astringency, bitterness, and aging behavior of red wines. Their bioavailability is still questioned [1,2], the interest of the scientific community towards phenolics, in particular trans-resveratrol and quercetin, has increased because they are accountable for several health-related effects correlated to wine intake [3]. Most odor compounds as monoterpenes are present both as free volatiles and non-volatile, glycosidically bound forms and represent a potential reservoir of flavor [4,5]

Methods

Results

Conclusion