Biochemical Traits, 1H NMR Profile and Residual DNA Content of 'Asprinio', White Wine from Campania Region (Southern Italy)

Abstract

'Asprinio' is a white dry wine characteristic for its acidity and aromatic flavour, known as emerging DOP wine in Southern Italy. Nevertheless, little information is available on the metabolomic profile of this wine. Thus, in this paper we evaluated the colourimetric parameters, ¹H NMR profiles and free amino acids content of 'Asprinio' wines, bottled by two different wineries (hereafter 'Asprinio_A' and 'Asprinio_B') collected in 2019 and 2020, using 'Greco di Tufo' for comparison. The colourimetric parameters are similar for both 'Asprinio' wines and differ from 'Greco di Tufo' wines. On the other hand, both ¹H NMR and free amino acid content profiles show different chemometric profiles among the three wines analysed, although the profiles are similar for both vintages. Moreover, the multivariate analyses carried out highlight differences between 'Asprinio_A' and 'Asprinio_B', which exbibit also different residual yeast and plant DNA. Overall, considering that the two-manufacturing wineries use 100% 'Asprinio' grape, the difference retrieved between the two 'Asprinio' wines could be explained by the different grapevine training systems: 'vite maritata' (training system inherited from Etruscans) for 'Asprinio_A' and 'guyot' for 'Asprinio_B'.

Keywords: 1H NMR; Vitis vinifera L.; free amino acids; geographical origin; wine; ‘Asprinio’.

Figure 1

Total phenol content and antioxidant capabilities in ‘Asprinio_A’, ‘Asprinio_B’ and ‘Greco di Tufo’, considering the 2019 and 2020 vintages. (a), total phenol content (TPC) expressed as mg of gallic acid equivalents (GAE) per L of each wine ± SD. (b) Trolox equivalent (TE) antioxidant activity from ORAC assay expressed as mmol of Trolox equivalents (TE) per L of each wine ± SD. boxed.

Figure 2

¹H NMR spectra of 3 representative samples of ‘Asprinio_A’, ‘Asprinio_B’ and ‘Greco di Tufo’.

Figure 3

Score scatter plot of PC1 versus PC2 obtained from the PCA of NMR data. The ellipse represents the Hotelling T2 with 95% confidence. A_A = ‘Asprinio_A’; A_B = ‘Asprinio_B’; GT = ‘Greco di Tufo’. The vintage is indicated by the numbers 19 (for 2019) and 20 (for 2020).

Figure 4

¹H NMR spectra of 3 representative samples of ‘Asprinio_A’, ‘Asprinio_B’ and ‘Greco di Tufo’, details of the aromatic region.

Figure 5

In (a–c), radar graph representing the free amino acid profile changes (percentage) in ‘Asprinio_A’, ‘Asprinio_B’ and ‘Greco di Tufo’, respectively, analysed in 2019 and 2020 vintages. In (d,e), radar graph representing the free amino acid profile changes of ‘Asprinio_A’, ‘Asprinio_B’ and ‘Greco di Tufo’, respectively, in 2019 or 2020 vintages. In (f), dendrogram corresponding to the cluster analysis of free amino acid profiles in ‘Asprinio_A’, ‘Asprinio_B’ and ‘Greco di Tufo’ from 2019 and 2020 vintages. Numbers on the dendrogram are bootstrap values (% of 1000 replicates).

Figure 6

In (a,b), relative quantification of grapevine and yeast DNA in ‘Asprinio_A’, ‘Asprinio_B’ and ‘Greco di Tufo’ samples in 2019 and 2020 vintages, respectively. Data are means of relative quantification measurements based on the ∆Ct Method ± SD; n = 3 biological replicates for each sample.