The Influence of Terroir on Phenolic Composition of Red Grapes , Elena 1 2* 1 3 4 Victoria ARTEM5 , Arina Oana ANTOCE , Aurora RANCA , Ancuţa NECHITA , Laura ENACHE POSTOLACHE 1 2Research Station for Viticulture and Oenology Murfatlar, Constanta, Romania University of Agronomical Sciences and Veterinary Medicine of Bucharest, Faculty of Horticulture, Bucharest,3 Romania 4Research Station for Viticulture and Oenology Iasi, Romania *)5Research Institute for Viticulture and Oenology Valea Calugareasca, Romania Research Station for Viticulture and Oenology Bujoru, Romania Corresponding author, e-mail: [email protected]; [email protected] BulletinUASVM Horticulture 73(2) / 2016 Print ISSN 1843-5254, Electronic ISSN 1843-5394 DOI:10.15835/buasvmcn-hort:12173 Abstract A rich content of phenolic compounds (anthocyans and tannins) is a fundamental technological condition for the obtaining of quality red wines - appreciated by increasing numbers of consumers, aware of the benefic health effects brought about by these biologically active compounds. The biosynthesis of phenols and their accumulation in the grape berries during ripening is influenced by a multitude of factors. In this study we focused on terroir and on the biological potential of the authorized red varieties for wines with controlled denomination of origin in four centres of three well-established viticultural regions: the Hills of Dobrogea, the Hills of Moldova, the Hills of Muntenia and Oltenia. The polyphenolic potential of the grapes was evaluated for the crop of 2015 by the standard Glories method, thus obtaining results for the total polyphenolic potential (ApH1), the extractable anthocyans potential (ApH3,2), the percentage of anthocyans extractability (%AE), the maturity of the seeds (MS) and total polyphenols (PT). By classifying the freshly harvested grapes on the basis of their phenolic potential using the statistical method of Principal Component Analysis, the studied varieties are clearly differentiated based on the viticulturalKeywords: terroir. grapes for red wines, extractable anthocyanins, polyphenols, seeds maturity INTRODUCTION in two different viticultural regions with different The quality of the grapes and, implicitly, of climatic conditions,et al leads to wines with a different the wines is determined by the conditions of the content of phenolic compounds in the same crop cultivation area, the characteristics of the year, year (Jiang ., 2011). the grapevine variety, the cultivation technology Environmental factors such as light and and, for the wines, by the winemaking technology temperature are those that directly affect the (Antoce, 2007). biosynthesis of phenolic compounds in the grapes The environmental factors (topographic, (Ferrer-Gallego, 2010). A series of experiments agro-pedological and climatic) included usually in aiming at documenting the influence of solar the French notion of “terroir” have a well known radiation on the synthesis of flavonoids could not influence on the quality of grapes and wines. It discriminate the independent effects of light active has been observed that the same variety, planted in photosynthesis, of ultraviolet radiation and 110 et al ARTEM temperature,et al leading to contradictory conclusions Romania has excellent conditions regarding depending on the studied viticultural region the productionterroir of quality wines, especially thanks (Downey o., 2006). to the soil and climate related factors, as part of Moderate temperatures during day and the so-called , which is very suitable for the night (15-25 C) promote the biosynthesis andoC cultivation of grapevine. accumulation of anthocyanins in the skins of the The aim of this work was to evaluate the grape berries, while temperatures exceeding 35 quali tative potential of the authorized black grape can affect the accumulation of these products varieties for the obtaining of red wines with by the inhibition of biosynthesis pathways. The controlled denomination of origin in different pigmentation of the grape berries is stimulated viticultural centres of Romania, under the by high light intensity, which increases the rate conditionsMATERIAL of year AND 2015. METHODS of transformation of leucoanthocyanins into anthocyanins; it is considered that, by stimulating photosynthesis, light promotes the accumulation Nine grapevine varieties were considered, of glucides, which are the primary compounds of which five autochthonous (Fetească neagră, used for the anthocyanins synthesis (La Iacona, Băbească neagră, Mamaia, Arcaş and Busuioacă 2012). de Bohotin) and four from the international Hydrological conditions represent another assortment (Cabernet Sauvignon, Merlot, Pinot important factor that affects wine quality, as noir, Burgund). Although the varieties Mamaia they strongly influence the accumulation of and Busuioacă de Bohotin are mainly used for phenolic compounds in the grapes, with water the production of rosé wines, they were included etdeficit al showing a definite positive effect on the in the study on account of being autochthonous accumulation of phenolic compounds (Esteban varieties (one very new, Mamaia, and one very old, ., 2001). For this reason, the distribution of Busuioacă de Bohotin) and are well adapted to the precipitations, their efficiency and the retention Romanian eco-climatic conditions, having good capacity of the soil are of great importance. prospects of being planted in increasingly larger Moreover, the characteristics of the soil such as surfaces. its thickness, structure, texture andet al.especially For each variety three batches of approxi- the degree of fertility, influence the phenolic mately 200 berries were harvested, packed in composition of grapes (Downey , 2006). plastic bags and transported carefully to the Among these factors, the greatest impact belongs laboratory, taking care not to crush the berries. to the water retention capacity and pH, which have Analyses were carried out on the same day as direct implicationset al on the absorption of macro- harvesting. The polyphenolic potential of grapes and microelements (Mateus Picero, 2008). In 2007 has been evaluated by the Glories method, which Castellarin . found that, under conditions of consists in extracting anthocyanins from the hydric stress, the content of proanthocyanidins in grape skin, first under mild conditions and then grapes increased, while other studies ethave al shown under severe conditions necessary for facilitating that restricted water resources did not have any the diffusion conditions. Two different aqueous effect on these compounds (Kennedy ., 2002). solutions are used: a solution of pH 1 (0.1 n HCl According to Downey (2006), the effect of the solution prepared with 8.33 ml of 37% HCl in water deficit correlates with a decrease in the 1000 ml distilled water) and a solution of pH 3.2 size of berries and changes in the ratio between (prepared by dissolving 5 g of tartaric acid in 800 skin and berry weight, which in turn affects the ml of distilled water, adding 22.2 ml NaOH 1n and concentration of phenolic compounds. water up to 1000 ml in a volumetric flask). The Other factors such as the macroclimate, method involves extraction of 50 g mashed grape latitude and altitude can also cause modifications skin with 50 ml of pH 1, while another 50 g of in the chemical composition of the grape berries. the mashed grape skin is subjected to extraction A number of authors have noticed an increaseet al of with pH3.2 solution. Both samples were manually the concentration of anthocyanins and flavones in stirred and allowed to rest for 4 hours at the room vineyards located at high altitudes (Bertelli ., temperature. Samples are then filtered, resulting 2 Bulletin2008). UASVM Horticulture 73(2) / 2016 solutions identified as „pH 1” and „pH3.2”. Analysis 111 The Influence of Terroir on Phenolic Composition of Red Grapes Tab. 1. Soil characteristics and climatic conditions of the vineyards considered in the study Viticultural center Soil and climatic conditions Murfatlar Dealu Mare Dealu Bujorului Copou-Iasi granular composition sand 23.0-48.0 36.5-62.2 43.9 37.1-41.0 (%) dust 29.0-46.0 15.4-24.9 31.9 21.7-28.5 Soil characteristics clay 13.0-36.0 6.2-42.6 24.2 30.5-38.2 Typical red Limestone Cambic Type of soil prediluvian soil Chernozem chernozem chernozem and mollisol Altitude o(m) 57-75 100 100 200 Slope (%)o 2.0-5.0 2.0-15.6 2.0-27.0 2.0-6.0 T max ( C) 40.9 35.6 37.3 37.0 Climatic o conditions in the Tmin ( C) 11.0 9.8 7.4 8.2 maturation period T average ( C) 26.2 22.8 21.9 22.0 (July, August, Sun exposure (h) 311.3 - 237.2 245.0 September) *is calculated only for SeptemberIndex cool of the night* 16.4 15.4 12.9 13.9 Precipitations (mm) 35.6 56.6 39.8 26.5 of anthocyanins is performed for both solutions, factors, providing favorable conditions for the using the differential pH method (Ribereau-Gayon, maturation of black grapes. 1976), the determinations being performed in 1 As shown in Table 1, the soil characteristics cm optical path length glass cuvettes, by using a (granular composition, texture, altitude and slope) Helios Alpha UV-VIS spectrophotometer, produced as well climatic parameters (maximum, minimum by ThermoScientific, USA. The total content and average temperatures, sun exposure and of phenols is determined only for the second precipitations) for the four viticultural centres solution, the pH3.2 at 280 nm, the determinations participating in this study (SCDVV Murfatlar, being spectrophotometrically performed by SCDVV Iasi, SCDVV