The anthocyanin profile of galician endangered varieties. A tool for varietal selection

Abstract

AIM: The current loss of genetic grapevine diversity is mainly due to the reduced number of varieties used for making wine. A way of preserved endangered varieties is the establishment of germplasm banks. The anthocyanin profile is a key factor in determining the oenological potential of red wine grape varieties. Thus, this work analyses the anthocyanin profiles of 29 varieties from the germplasm bank located in ¨Estación de Viticultura y Enología de Galicia¨ (EVEGA), Ourense (Galicia, Northwest Spain) in 2018 and 2019 seasons. 

METHODS: At harvest, grapes were picked up and the anthocyanin substances were extracted and analyzed by HPLC (1, 2). Results were subjected to statistical analysis, ANOVA (factor variety) and Principal Component Analysis (PCA).

RESULTS: The anthocyanins were identified as the monoglucoside (GLU) acetylglucoside (AC) and p-coumaroylglucoside forms (CM) of cyanidin (Cy), delphinidin (Dp), malvidin (Mv), pelargonidin (Pel), peonidin (Pn) and petunidin (Pt). Sixteen compounds were identified and quantified (mg/Kg of berry fresh weight, FW). Significant diferences between varieties (p<0.001) were found for the biannual means of all compounds. MvG had the highest content in all varieties analyzed, with the exception of Zamarrica, Xafardán, Moscatel de Hamburgo and Brancellao. Respect to the rest of varieties, Sousón, Castañal, Ferrón, Espadeiro and Caíño Bravo (1832, 1323, 1327, 1173 and 1097 mg/Kg FW respectively) showed the highest contents of Total Anthocyanin. It is worth noting that these varieties belong to the same genetic population (3).These contents were higher than those found in Mencia (643 mg/Kg FW) and Tempranillo (891 mg/Kg FW), varieties widely cultivated in Galicia and Spain respectively.

Application of Principal Component Analysis (PCA) to experimental data showed a good separation of varieties according to the anthocyanin profile. (71.32 and 74.22 % of the total variance in 2018 and 2019 respectively). PCA also showed a group including Ferrón, Sousón, Castañal and Espadeiro varieties related to high contents of ΣGLU, ΣDel, ΣPet and ΣMal

CONCLUSION

 Results demonstrated a high degree of anthocyanin profile difference between the varieties analyzed. Due to their anthocyanidin profile some of these varieties could play an important role in the red winery industry.