Researches concerning the evolution of grapes ripeness in some varieties from Recaş vineyards

Volume 18(1), 174-181, 2014 JOURNAL of Horticulture, Forestry and Biotechnology www.journal-hfb.usab-tm.ro Researches concerning the evolution of grapes ripeness in some varieties from Recaş vineyards Dobrei Alina Georgeta 1*, Dobrei A. 1, Sala F. Drăgunescu Anca 1, Cristea T. 1, Costea B. 1 2, Nistor Eleonora 1, Mălăescu Mihaela 1, 1 USAMVBT, Faculty of Horticulture and Forestry; 2 USAMVBT, Faculty of Agriculture *Corresponding author. Email: ghitaalina@yahoo.com Abstract Research was carried out between 2012-2013 years in the S.C. Recaş S. A. vineyard. Timis. Thirteen varieties of grapes for wine were taken for investigation, of which 7 varieties of grapes for white wine (Italian Riesling, albă, regală,, Pinot gris, Mustoasă and Muscat Ottonel) and 5 grape varieties of red wine (Burgundy, Cabernet, Cadarca, Merlot, Pinot noir). The purpose of this work was to study the berries weight, sugar and acidity content of grapes varieties studied. Evolution of the grapes ripening process, physical and chemical changes occurring in berries vary greatly depending on the variety, vineyard, soil tillage system, but especially depending on the climatic conditions of the year. Therefore the maturation process should be study each year, for each variety and each ecosystem separately. The ripening of grapes influences also the must efficiency after processing, and especially the composition and quality of the wine resulted. Alongside the red wine grape varieties, good results have been achieved also in white wines, resulting in wines of very good quality in Muscat Ottonel, Italian Riesling and regală varieties. Key words grapes variety, acidity, organoleptic properties, grape maturation To can carry out vital processes harmoniously, grapevine needs a certain level of natural and man-made conditions. The way how specific biological requirements for different varieties of vines are satisfied by the given conditions, depend the growing and fructification of plants, quantity, quality, crop consistency and ultimately the plants longevity. [2]. Knowing the the biology grapevine is particularly important for determining agrophytotechnical measures aiming obtain both the great productions and good quality and maintaining the biological equilibrium of the vine. [1] [3]. A special importance presents the study of the physical and mechanical grape composition and physico-chemical characteristics of must and wine, and also the different processes of winemaking influence on the quantity and quality of the final product. [4] Evolution of the grapes ripening process, physical and chemical changes occurring in berries vary greatly depending on the variety, vineyard, soil tillage system, but especially depending on the climatic conditions of the year. Therefore the maturation process should be study each year, for each variety and each ecosystem separately. [6] The ripening of grapes determines also the must efficiency after processing, and especially the composition and quality of the wine resulted. An early harvest determined a low must efficiency having a negative influence on wine quality, while the delayed harvesting causing crop losses that can t always be compensated by extra wine quality. [5] Another reason which determined the necessity for an optimal timing of harvesting is that not all varieties ripen at the same time in autumn and not at the same time every year. A. Veres shows that increasing the yield per hectare and the quality of wine in optimal operating conditions of the biological potential of the hub are required deep knowledge of genetics, biology, biochemistry and ecology of the vine. Materials and Methods Research was carried out among 2012-2013 in S.C Recaş S. A. vineyard, Timis. Thirteen varieties of grapes for wine were taken for investigation, of which 7 varieties of grapes for white wine (Italian Riesling, albă, regală,, Pinot gris, Mustoasă and Muscat Ottonel) and 5 grape varieties of red wine (Burgundy, Cabernet, Cadarca, Merlot, Pinot noir). The purpose of this work was to study the berries weight, sugar and acid content of grapes varieties studied. For establish the timing of grape ripening in studied varieties, in Recaş vineyards, was used the physical-chemical analysis method, which consists of: - Determining the weight of 100 berries; - Dosing sugar; - Determination of total acidity in the grapes; [6] 174

All these determinations were made from to the first stage of berry ripening to harvest at the same dates, from five to five days. In order to determine the weight of 100 grape berries were sampled from uniformly spread over hubs, from different parts of the hub, the better grapes exposed to sun or better shade, to reflect the real situation in the vineyard. In the laboratory, in each sample were analyzed 400-500 berries, which were detached with scissors at the brush base. The berries were weighed 400-500 each time with a precision scale. The total weight was determined by calculating the weight of 100 berries, and results obtained are listed in tables. Then berries were subjected to pressing in laboratory, and dosages of sugar in the grape must were made after a pre-washed settling (12 h). [6] Sugar calculation was made of by refractometry, and determination of total acidity by the titrimetric method. Results Evolution of the 100 berries weight, of sugar and acidity content in 2012 Data on the evolution of the 100 berries weight, sugar and acidity content in 2012, can be found in Tables 1 and 2. The weight of 100 berries weighed on 5 October, ranged from 106 g in to 270 g Cadarca variety. Data of the table 2 shows that the evolution 100 berries weight had an upward trend along with ripening advancing excepting Pinot noir and Merlot cultivars, which have small fluctuations in September. [6] Sugar accumulation were also placed on an ascending scale along with ripening advancing, accumulation being quite significant, due to the relatively high temperatures and low precipitation fallen for the period of observations. On October 5, the amount of sugar accumulated range between 144 g/l in Italian Riesling to 222 g/l in Burgundy variety. Evolution of the 100 berries weight, of sugar and acidity content in 2012 a) white wine varieties Variety/ Anaylesed August September October Cultivar items 26 31 5 10 15 20 25 30 5 10 68 72 74 82 82 83 101 105 120 145 Italian 63 69 77 94 97 116 127 136 144 186 Riesling 15,1 14,7 14,3 14,0 13,8 12,7 9,8 9,6 8,3 5,4 regală albă Pinot gris Mustoasă Muscat Ottonel 65 69 72 83 87 90 95 98 108-110 116 120 127 147 168 186 197 206-12,8 12,2 11,9 11,3 9,1 8,3 7,1 6,7 7,0-65 71 75 89 100 101 104 113 125-88 90 94 108 116 127 138 155 158-15,3 14,9 14,2 13,2 10,7 10,8 10,2 8,5 7,9-63 73 76 80 97 108 109 112 116 116 122 129 135 142 159 182 197 205 209 221 12,7 12,1 11,2 10,8 10,6 9,4 8,3 7,5 7,4 4,7 66 70 72 81 90 85 104 106 106 122 98 106 111 116 123 153 160 181 193 204 14,3 13,9 13,7 13,4 12,3 10,7 8,3 6,8 6,3 5,3 155 170 185 202 206 212 222 230 230-58 88 110 120 134 155 160 165 165-22,3 17,1 13,2 11,3 10,4 9,6 8,4 7,9 7,0-163 177 190 205 212 214 217 220 225-127 152 158 191 205 212 215 217 220-6,4 5,6 4,9 4,4 4,2 3,8 3,6 3,3 3,3 - Table 1 In this case too, the acidity ranged in the appropriate level fits in the limits imposed by production departments of Recaş Winery. On September 30, at lower limit stood Muscat Ottonel (3.3 g/l) and to the upper limit the Italian Riesling variety (8.3 g / l). 175

Table 2 Evolution of the 100 berries weight, of sugar and acidity content in 2012 b) red wine varieties Soiul Elemente August Septembrie Octombrie analizate 26 31 5 10 15 20 25 30 5 10 94 101 105 110 113 112 117 109 120 126 Cabernet 110 131 160 176 180 186 190 198 218 218 12,5 10,7 8,4 7,4 7,3 6,5 6,4 5,6 5,2 5,0 135 160 190 202 206 226 233 240 243 - Burgund 125 145 174 185 190 199 210 222 222-10,0 7,4 6,3 6,0 5,9 5,3 5,1 4,8 4,8-123 149 159 164 154 145 141 134 134 130 Pinot noir 140 153 200 208 208 210 215 224 220 220 8,5 7,5 6,5 6,2 6,0 5,6 5,1 4,9 4,6 4,5 121 136 145 148 138 128 128 136 137 137 Merlot 115 140 158 178 202 200 200 205 207 208 11,8 9,6 8,5 7,5 6,8 6,6 5,5 5,3 5,0 4,9 204 224 226 140 256 276 271 270 270 270 Cadarcă 85 85 87 112 130 140 150 156 161 178 11,6 10,1 8,8 7,6 7,3 6,5 6,1 6,0 6,0 5,8 Industrial or technological maturity of the grapes is reached when the composition is optimal for the preservation of a specific type of wine or other products made by grapes, must or wine. Graphically, the ripening evolution of grape varieties for white wine is given by chart 1, and for the red wines by chart 2. Watching the chart 1, it is noted that: - Weight of 100 berries increased approximately constant until 20.IX, followed by stagnation between 20.IX - 30.IX, and by a slight increase towards the end of the observation period; - Accumulation of sugar increased steadily by about 8-10 units per interval; - Acidity decreased with the increase of sugar content, the decrease being of about 7 to 10 units per period. Figure 1. Evolution of grape ripening in white wine varieties in 2012 250,00 200,00 150,00 100,00 50,00 0,00 26.aug 31.aug 05.sep 10.sep 15.sep 20.sep 25.sep 30.sep 05.oct 10.oct Analyzing the three factors and the correlation among them, shows that grape varieties for white wine have reached full maturity around 20.IX date, actually this time being forwarded, harvesting to start actually at 15.IX. Watching figure 2, is observed that: - Weight of 100 berries rose sharply between 26.VIII - 31. VIII, then steadily increased; - Accumulation of sugar has increased steadily since the beginning of the observation period up to the end of it; - Acidity decreased, along with the accumulation of sugar, first sharply between 26.VIII - 5.IX, then constant until the end of the observation 176

period. Based on the chart 2, it can be concluded that red wine grape varieties have reached full maturity and therefore could be harvest around the 10.IX, in vineyards the harvesting period starting all around this date. Figure 2 Evolution of grape ripening in red wine varieties in 2012 250,00 200,00 150,00 100,00 50,00 0,00 26.aug 31.aug 05.sep 10.sep 15.sep 20.sep 25.sep 30.sep 05.oct 10.oct Evolution of the 100 berries weight, of sugar and acidity content in 2013 Observations and analyzes carried out in 2013 are shown in Tables 3 and 4. According to the data of tables 3 and 4, concerning the evolution of 100 berries weight, is found that in this case also had an upward trend in most varieties except varieties: Cadarca, Merlot, Cabernet, where the increase had small fluctuations in September, due to prolonged drought. On 30.IX, 100 berries weight ranged from 94 g in alba and 266 g in Cadarca variety. Sugar content increased also in this trial, with the passing of started of ripening period and approaching full maturity, sugar accumulation being influenced by the high temperatures in this period. Evolution of berries weight, of sugar and acidity content in 2013 a) White wine varieties Variety/ Analyzed August September Cultivar items 26 31 5 10 15 20 25 30 64 68 70 78 78 79 97 101 Italian 88 104 115 124 147 173 182 196 Riesling 14,5 14,1 13,7 13,2 12,8 11,7 8,8 5,1 albă regală Pinot gris Mustoasă Muscat Ottonel 61 65 68 79 83 86 91 94 115 121 125 134 157 178 196 207 12,2 11,6 11,1 10,5 8,5 7,3 6,1 5,7 61 67 71 85 96 97 100 109 93 99 104 118 126 137 148 165 14,7 14,3 13,6 12,2 9,7 9,8 9,2 7,5 59 69 72 76 93 104 105 108 127 134 145 152 169 193 207 215 12,1 11,5 10,7 9,8 9,6 8,4 7,3 6,5 62 66 68 77 86 96 100 102 103 111 116 126 133 163 170 191 13,7 13,3 13,1 12,4 11,3 9,7 7,3 5,8 151 166 181 198 202 208 218 226 63 93 113 130 144 165 170 175 21,7 16,5 12,6 10,5 9,4 8,6 7,4 6,9 159 173 186 201 208 210 213 216 133 158 167 201 215 222 225 227 5,8 4,8 3,9 3,4 3,2 2,8 2,6 2,3 Table 3 177

b) Red wine varieties Variety/ Analyze Cultivar d items Cabernet Burgund Pinot noir Merlot Cadarcă Evolution of berries weight, of sugar and acidity content in 2013 August September 26 31 5 10 15 20 25 30 90 97 101 106 109 108 113 105 115 138 169 186 190 196 200 208 11,9 10,1 7,6 6,4 6,3 5,5 5,4 4,6 131 156 186 198 202 222 229 236 130 153 186 195 200 209 220 232 9,4 6,6 5,3 5,0 4,9 4,3 4,1 3,8 119 145 155 160 150 141 137 130 145 160 208 218 218 220 225 234 7,9 6,8 5,5 5,2 5,0 4,6 4,1 3,9 117 132 141 144 134 124 124 132 120 147 168 188 212 210 210 215 11,2 9,0 7,6 6,5 5,8 5,6 4,5 4,3 200 220 222 136 252 272 267 266 90 92 107 122 140 150 160 166 11,0 9,5 7,8 6,6 6,3 5,5 5,1 5,0 Table 4 Burgundy, Pinot noir and Muscat Ottonel varieties, have accumulated the largest amounts of sugar, while alba and Cadarca varieties, accumulated the lowest amounts of sugar. Acidity was lower, along with the advancement in ripening with different values from variety to variety, but still falling within the specific value for each variety, although high temperatures and the lack of rainfall resulted in a lower acidity than normally in this area. At 30.IX, the lowest acidity was recorded in Muscat Ottonel variety 2.3 g/l H 2 SO 4 and highest in regală 7.5 g/l H 2 SO 4. Graphically, the evolution of grapes ripening is shown in Figure 3, for white wines varieties and in Figure 4, for red wine varieties. From Figure 3, it is noted that: - Weight of 100 berries has steadily risen until 30.IX, then remained almost constant until the end of the observation period, when there was a slight decrease; - Sugar accumulation increased steadily by about 8-11 units/period; - Acidity decreased along with the increase in sugar content, the decrease being about 7-10 units/period. Analyzing the all three factors shows that white wine grape varieties have reached full maturity around the 20.IX date, and harvesting starting actually on 10.IX. From Figure 4, it is noted that: - Weight of 100 berries rose sharply among 26.VII-31.VIII, and then increased steadily until the end of the observation period; - Sugar accumulation increased steadily until the end of the observation period; - Acidity declined along with sugar accumulation, more abruptly within 26.VIII-31.VIII, followed by a steady decline until the end of the observation period. 178

Figure 3. Evolution of grape ripening in white wine varieties in 2013 250,00 200,00 150,00 100,00 50,00 0,00 26.aug 31.aug 05.sep 10.sep 15.sep 20.sep 25.sep 30.sep Figure 4. Evolution of grape ripening in red wine varieties in 2013 250,00 200,00 150,00 100,00 50,00 0,00 26.aug 31.aug 05.sep 10.sep 15.sep 20.sep 25.sep 30.sep The figures 5 and 6 illustrate mean of berries weight, of sugar and acidity content from white and red wine varieties. 179

250 200 150 100 50 Figure 5. Mean of berries weight, of sugar and acidity content from white wine varieties (2012-2013) 0 Riesling italian albă regală Pinot gris Mustoasă Muscat ottonel Figure 6. Mean of berries weight, of sugar and acidity content from red wine varieties (2012-2013) 300 250 200 150 100 50 0 Cabernet Burgund Pinot noir Merlot Cadarcă Conclusions After the finishing of observations and processing data concerning the evolution of grape varieties ripening for white wine and red wine in Recaş Winery in 2012 and 2013, can be draw the following conclusions: Berries growth is a continuous process, with different rates of development depending on variety and climatic conditions; [6] High humidity causes large increases in berries weight, while high temperatures causes water loss through evaporation and thus a slight decrease in the berries weight; From the first stage of ripening and full maturity occur the intensification of sugars accumulation; In all varieties is reported that before full maturity and during berries maturation, took place an intense rate of sugars accumulation; Acidity diminishing determines the increasingly rate of sugars in the must; Along with the advancement in ripening, acidity decreased with different values from variety to variety, depending on the climatic factors; To obtain wines with required parameters (alcohol, acidity, residual sugar), the time of harvest is of great importance, the results obtained indicating the conclusion that the previously established date corresponded most often with harvest start date in Recaş winery; The evolution of grapes ripening is greatly 180

influenced by the climatic factors in the months from August to October and the tillage applied. [6] Results of the research revealed that for the climatic conditions of Recaş vineyards can be get high-quality wines from almost all the varieties studied. By tradition, Recaş was famous mostly because its red wines of very good quality Cabernet, Merlot, and Cadarca. Along with the red varieties, good results were obtained in white wines, yielding high-quality wines for Muscat Ottonel, Italian Riesling and regală, which is recommended to be retained in the assortment, being preferred especially by the native consumers. Bibliography 1.Dobrei A., Kuljancic I.,Bongiraud C.,Mălăescu Mihaela, 2001 - Cercetări privind desfăşurarea fazelor de vegetaţie la câteva soiuri de struguri pentru vin în anul 2000, cultivate în ecosisteme diferite, Cercetări ştiinţifice., seria a Va, Facultatea de Horticultură Timişoara; 2.Dobrei Alin, Mustea Mihai, Liliana Rotaru, 2005 - Cultura viţei de vie, Ed. Solness, Timişoara; 3.Dobrei A., Iova G., Mălăescu Mihaela, Dărăbuş Rodica, Ghiţă Alina, Ţâru Viorica, 2004 - The researches concerning the fertility and productivity of some grape wine varieties used for wine, Cercetări ştiinţifice, Horticultură, seria a VIII-a, Editura Agroprint, Timişoara; 4.Ghiţă Alina şi col., 2011 Oenologie, Ed. Solness, Timişoara; 5.Iova Gh., Dobrei A., Georgiu I., 1998 - Comportarea soiurilor pentru vinuri albe în condiţiile centrului viticol Recaş, Cercetări ştiinţifice, Horticultură, Editura Agroprint, Timişoara; 6.Mălăescu Mihaela şi col, 2007 - Cercetări privind însuşirile tehnologice ale unor soiuri de struguri pentru vin în condiţiile Centrului Viticol Recaş, Lucrari ştiinţifice, Facultatea de Horticultură, Universitatea din Craiova. 181