Assessment of nutritional parameters of native apple cultivars as new gene sources

27 ACTA UNIVERSITATIS AGRICULTURAE ET SILVICULTURAE MENDELIANAE BRUNENSIS Volume LX 3 Number 5, 2012 ASSESSMENT OF NUTRITIONAL PARAMETERS OF NATIVE APPLE CULT IVARS AS NEW GENE SOURCES J. Balík, O. Rop, J. Mlček, P. Híc, M. Horák, V. Řezníček Received: April 6, 2012 Abstract BALÍK, J., ROP, O., MLČEK, J., HÍC, P., HORÁK, M., ŘEZNÍČEK, V.: Assessment of nutritional parameters of native apple cultivars as new gene sources. Acta univ. agric. et silvic. Mendel. Brun., 2012, LX, No. 5, pp. 27– 38 Although there are tens of diff erent apple varieties in Europe, only some of them were purposefully bred and selected in the past. In spite of the fact that they can have outstanding nutritional and technological properties, the majority of them are of only a local importance. The objective of this study was to show and popularize altogether 35 local apple varieties which are typical of the conditions of Central Europe. However, their genetic uniqueness represents an irreplaceable ecological wealth and for that reason these local varieties could become a new and outstanding source of nutrients and food. Today, they can be used not only for direct consumption and in food industry but also as a potential material for further breeding and selection. It was found out in our experiments that the highest content of total acids was shown by the variety ’Citronové zimní’ (6.1 g.kg−1 of fresh matter). As far as the content of pectins was concerned, the highest levels were found out in the variety ’Strymka’ (3.26% in fresh matter). Of minerals, potassium showed the highest levels in fruit; for example, the variety ’Boikovo’ contained 9.70 ppm of this element in dry matter. Peels showed approximately 7 times higher antioxidant capacity than the fl esh. For example, peels of the variety ’Bernské růžové’ showed antioxidant capacity of as much as 56.65 mmol of trolox per kg of fresh matter. This paper should contribute to eff orts focused on saving of genetic variability of apples and their further application both in human nutrition and a further breeding and selection under conditions of pomological and alimentary practice. apples, local varieties, titrable acidity, pectins, minerals, antioxidant capacity Today, apple trees are the most popular and the most grown core fruit species in Europe. Due to their nutritional properties, apples are rather valued as fruit species (Gallus et al., 2005). Thanks to the content of minerals and polyphenolic compounds the consumption of apples is recommended to prevent cardiovascular or oncogenic diseases (Wojdylo et al., 2008). In association with the process of intensifi cation of agricultural production, the last century was characterised by extensive growing and breeding of only several selected and nowadays commercially successful apple varieties. Tens of others are only on the margin of general interest. A further propagation of local (native) cultivars is prevented above all by the fact that their sensory and technological properties are not as good as those of purposefully bred and selected ones although their local importance may be rather considerable (Goland and Bauer, 2004). Nevertheless, many of these native varieties show a signifi cant tolerance to pathogens and pests, a high adaptability to less favourable climatic and soil conditions, good resistance to stress (Tetera, 2003) and the uniqueness of their relationship to nutritional properties (Toth et al., 2004). In the Czech Republic, apple trees are the most frequent fruit species. The main objective of this paper is to emphasize some nutritional parameters of 35 typical Czech local apple varieties. During the process of landscape cultivation and care, 28 J. Balík, O. Rop, J. Mlček, P. Híc, M. Horák, V. Řezníček many of the recommended apple varieties were spreading in Bohemia and Moravia in the past. This process was also accompanied with the selection of local apple varieties (Hričovský et al., 2003). The described varieties, however, could partly fi nd a wider application in human nutrition (Monschein et al., 2006) and it is also necessary to mention the possibility of their application in the breeding work and selection (Laurens, 1996). MATERIAL AND METHODS The main hypothesis of this paper is not to prove the dependence existing between model factors on the one hand and nutritional parameters on the other. Its main objective is to emphasize the abundance of genetic diversity as related to growing and utilisation of apple trees above all due to the fact that the Czech Republic represents historically one of the richest breeding potentials in the world. For experiments, altogether 35 apple varieties were used; some of them, however, originated not only from Bohemia and Moravia but also from some other countries. In spite of this, the majority of them are typical just of the territory of Central Europe and it is not possible to neglect or ignore their, o en hundred-year-old, use for nutritional purposes (Tetera, 2006). This paper compares nutritional parameters of individual varieties, tries to point out their prospects and to contribute to the preservation of their originality for the contemporary pomicultural practice. Its most important objective is to save the genetic variability of apple trees and to enable their further use in the fi elds of human nutrition and pomicultural practice. Sample collection and their preparation for chemical analyses Apples were harvested from fi ve trees of each variety under study in the stage of consume ripeness. Each of these samples involved 3 replications from each tree (i.e. altogether 15). The samples were stored in a controlled environment at the temperature of + 2 °C and under conditions of 85% of relative humidity (Kyzlink, 1990). For analyses all fruit without core were used (i.e. peel and fl esh together). The samples were obtained from 35 apple tree varieties, 29 of which originated from the Tišnov region. The other samples were harvested in the White Carpathians in the cadastre of Valašské Klobouky. In the past the White Carpathians were declared as a protected landscape area and the described varieties are quite typical of this region (Tetera, 2006). Description of locality Tišnov Fruits were harvested in experimental orchards of Mendel University in Brno. These orchards are situated in the Tišnov vicinity, the Czech Republic. The average altitude is 435 m above sea level, and the mean annual temperature and precipitation are 7.5 °C and 696 mm, respectively. The soil type was classifi ed as the Mesotrophic Cambisol. Description of locality Valašské Klobouky Fruits were harvested in experimental orchards of Tomas Bata University in Zlin. These orchards are situated in the south-western part of the White Carpathians near Zlín, the Czech Republic. The average altitude is 340 m above sea level, and the mean annual temperature and precipitation are 7.9 °C and 760 mm, respectively. The soil type was classifi ed as the Mesotrophic Cambisol. Chemical analyses With the exception of the determination of pectin substances, vitamin C and antioxidant capacity, all other chemical analyses were performed using the standard methods described by Novotný (2000). Dry matter content was measured a er drying off to a constant weight at the standard temperature of 105 ˚C ± 2 ˚C – the apparatus VENTICELL 111 (BMT, Brno, Czech Republic). Soluble solid content (SSC) was estimated by means of polarimetric measurements in juice obtained a er squeezing the fruit using a digital instrument HI 96801 (Hanna Instruments, Woonsocket, RI, USA). The content of total acids was measured by potentiometric titration; 20 g of homogenised sample were extracted for 30 minutes in a shaker in 200 ml of re-distilled water at the temperature of 80 °C. The obtained extract was fi ltered and titrated with sodium hydroxide to the pH value of 8.1 by using the apparatus pH211 (Hanna Instruments, Woonsocket, RI, USA). The obtained result was converted to the content of acids in g.kg−1 of fresh matter (FM). Mineral content assay The sample was dried off to a constant weight – the apparatus VENTICELL 111 (BMT, Brno, Czech Republic) – in a drier at the temperature of 105 °C ± 2 °C. A portion of 1g of homogenised dry matter (DM) (the size of particles up to 1 mm) was therea er mineralized in a mixture of concentrated sulphuric acid and 30% hydrogen peroxide. Mineralized samples were quantitatively transferred into a 250 ml volumetric fl ask and its volume was refi lled to the volume with re-distilled water. The mineralizate was measured in an atomic absorption spectrometer PHILIPS PU 9200X (Philips, Amsterdam, the Netherlands). The content of total nitrogen was measured according to Kjeldahl using the apparatus KJELTEC TM 2300 (Foss, Hillerod, Denmark). The amount of minerals was expressed as ppm (respectively ppb) in DM. Pectin substances content assay The content of pectins was measured by means of a modifi ed method described by Rop et al. (2008). A pulp sample (10 g) was extracted at the temperature of 80 °C in a shaker with hydrochloric acid c = 1 mol.dm−3 for a period of 90 minutes. The obtained hydrolyzate was quantitatively transferred into a 250 ml volumetric fl ask and refi lled to the volume with water. Pectins Assessment of nutritional parameters of native apple cultivars as new gene sources 29 were therea er measured photometrically as a coloured complex consisting of the product of thermal decomposition of galacturonic acid with m-hydroxybiphenyl in concentrated H2SO4. The samples of 5 ml were gradually taken off and put into 50-ml fl asks; therea er, they were mixed with 6 ml of sodium tetraborate (c = 0.013 mol.dm−3) dissolved in concentrated sulphuric acid, fi lled up to the volume with distilled water and boiled for 5 minutes. Boiled samples were let to stand for 20 minutes and therea er they were measured (at 520 nm) together with standards in the apparatus LIBRA S6 (Biochrom Ltd., Cambridge, UK). The content of pectins was expressed in percents of fresh matter. Determination of ascorbic acid The determination of ascorbic acid content was carried out by a modifi ed method of Wagner et al. (1979) and Miki (1981). 5 g of the sample were weighed in Erleymayer fl ask by adding 25 ml of extractant methanol: H2O:H3PO4 in the ratio 99:0.5:0.5. The fl ask with the samples was placed into a water bath with the temperature of 25 °C where the samples were extracted for 15 minutes. To keep out the samples of daylight, the fl ask was covered with aluminium foil during the preparation. A er the extraction the content of the bank was fi ltrated through paper Filtrapak No. 390. The fi ltrate prepared in this way before injection was diluted in ration of extractant and fi ltrated again through a membrane fi lter Nylon (0.45 μm Nylon fi lter disk). The instrument used for ascorbic acid analysis consisted of a solvent delivery pump (ESA Inc., Chelmsford, USA) – Model 582, guard cell (ESA Inc., Chelmsford, USA) – Model 5010A, working electrode potential K1 = 600 mV, K2 = 650 mV, chromatographic column – Model Supelcosil LC8 (150.0 x 4.6 mm), 5 μm particle size and an electrochemical detector (Coulochem III). Chromatographic conditions were constant: 30 °C, as a mobile phase methanol was used: H2O:H3PO4 = 99:0.5:0.5, (fi ltrated through a fi lter Nylon, 0.2 μm), type of .elution was isocratic, the fl ow rate of the mobile phase was 1.1 ml.min−1, retention time 1.9– 2.0 min. The content of ascorbic acid was calculated as mg.100 g−1 of fresh matter. Antioxidant capacity assay The peel was separated from three parts of the fruit with the scalpel and cut to pieces. The fl esh was cut out from all the apple length in a shape of 3 cylinders with a diameter of 2 mm. The weight of 0.5 g was separated from the homogenised samples and immediately 3 ml of 50% methanol were added. A er 15 minutes of extraction centrifugation at 3,000 rpm was performed. The antioxidant capacity was determined by photochemiluminescence method (PCL) using KIT ACL (400.803) and the instrument Photochem (Analytik Jena AG, Germany). Free radicals (superoxide anion radicals) were produced by optical excitation (irradiation) of a photosensitiser (dye). These radicals were partially eliminated from the sample by reaction with the antioxidants present in the sample. The remaining radicals cause the luminescence in the measuring cell, thereby allowing determination of the antioxidant capacity of the extract sample. The samples were diluted to give signals lying within the range of the calibration curve and within the linear range of the instrument. The total antioxidant capacity (TAC) of the fresh apple fl esh or fresh aplle peel was quantifi ed by comparison with the Trolox standard (Balík et al., 2008). Statistical evaluation All results were evaluated using the ANOVA variation statistics programme. Statistical data were calculated according to Snedecor and Cochran (1967) when using the statistical package Unistat, v. 5.1 and Offi ce Excel® Microso . RESULTS When evaluating the overall average values with regard to individual apples, the highest weights of one fruit were recorded in the varieties ’Sikulské’ (on average 236.3 g) and ’Lebelovo’ from the locality near Tišnov (200.7 g). Also in the other locality there were relatively high average weights of ’Lebelovo’ apples. Higher weights were for example recorded also in the varieties ’Limburské’, ’Krasokvět’ or ’Croncelské’ (Tab. I). The variety ’Sikulské’ showed also the highest content of dry matter (16.51%). More than 16% of dry matter was recorded also in the varieties ’Starkrimson’, ’James Grieve’ and ’Hvězdnatá reneta’. The variety ’Starkrimson’ showed a high content of soluble solid content (16.10% FM). In the variety ’Strýmka’ this value was 15.68%. More than 14% of soluble solid content in FM was shown also in the varieties ’Panenské české’ and ’Citronové zimní’ (Tab. I). The titration acidity and the content of pectin substances were other important technological parameters estimated in altogether 35 samples of varieties under study. In this case there were considerable diff erences among individual varieties. As far as the total content of acids was concerned, the measured values ranged from 1.3 g.kg−1 FM (’Coxova reneta’) to 6.1 g.kg−1 FM (’Citronové zimní’). Diff erences were also found out in the contents of pectins. The lowest levels were found out in the varieties ’Lebelovo’ from the Tišnov region (1.11% FM) and ’Boikovo’ (1.14% FM). The varieties ’Croncelské’ and ’Jeptiška’ contained both 1.15% FM while the highest one was found out in the variety ’Strýmka’ (3.26% FM). Of mineral elements, the highest contents in dry matter were those of potassium and the variety ’Boikovo’ contained as much as 9.70 ppm. High contents of potassium were also found in the varieties ’Jeptiška’, ’Gustavovo’, ’Grávštýnské’ or ’Albrechtovo’. In these varieties there were also high contents of other macroelements, above all of 30 J. Balík, O. Rop, J. Mlček, P. Híc, M. Horák, V. Řezníček nitrogen (Tab. II). So, for example, a high content of nitrogen was found out in the variety ’Boskoopské’ (4.50 ppm). The highest levels of phosphorus (1.07 ppm) were found out in the varieties ’Bláhovo oranžové’ and ’Jadernička moravská’. As far as the other elements were concerned, the content e.g. of calcium ranged from 0.35 ppm (the variety ’Vilémovo’) to 0.82 ppm (the varieties ’Boikovo’ and ’Gustavovo’). In case of magnesium this range had limits of 0.23 ppm (the variety ’Bernské růžové’) and 0.41 ppm (the varieties ’Croncelské’ and ’Jeptiška’) while in case of sodium the values ranged from 48 ppb (the variety ’Sláva světa’) to 190 ppb (the variety ’Krátkostopka královská’). In the varieties harvested in the locality Valašské Klobouky the contents of vitamin C and of total antioxidant capacity were measured as well. While in the fl esh the values of total antioxidant capacity ranged from 4.02 (the variety ’Vilémovo’) to 6.59 mmol of trolox.kg−1 FM (the variety ’Bernské I: Selected quality parameters of apple cultivars (n = 15) Cultivar Fruit weight (g) Dry matter (%) Soluble solid content (%) Titratable acidity (g.kg−1) Pectins (%) Albrechtovo/VK* 99.2 ± 7.6** 11.14 ± 0.03 13.50 ± 0.12 3.80 ± 0.27 2.01 ± 0.04 Baumannova reneta/Ti 142.6 ± 6.4 12.81 ± 0.02 13.85 ± 0.01 4.28 ± 0.28 2.90 ± 0.04 Bernské růžové/VK 80.5 ± 5.1 11.23 ± 0.15 11.70 ± 0.18 2.64 ± 0.12 2.19 ± 0.01 Bláhovo oranžové/Ti 89.7 ± 4.8 15.04 ± 0.05 12.96 ± 0.02 2.10 ± 0.52 1.78 ± 0.09 Boikovo/Ti 110.4 ± 10.3 17.23 ± 0.03 13.22 ± 0.02 1.93 ± 0.13 1.14 ± 0.03 Boskoopské/Ti 136.5 ± 9.7 13.67 ± 0.03 12.51 ± 0.01 1.90 ± 0.18 2.45 ± 0.08 Citronové zimní/Ti 154.1 ± 8.2 15.97 ± 0.06 11.14 ± 0.01 6.10 ± 0.48 1.50 ± 0.05 Coxova reneta /Ti 90.7 ± 7.6 10.62 ± 0.17 14.35 ± 0.02 1.30 ± 0.29 2.12 ± 0.16 Croncelské/Ti 168.3 ± 10.4 15.24 ± 0.28 14.22 ± 0.02 2.50 ± 0.24 1.15 ± 0.04 Gdánský hranáč/Ti 75.0 ± 3.9 13.44 ± 0.05 11.16 ± 0.01 4.30 ± 0.36 2.87 ± 0.51 Grávštynské/Ti 126.8 ± 7.1 10.83 ± 0.05 13.87 ± 0.02 2.35 ± 0.13 1.44 ± 0.02 Gustavovo/Ti 99.3 ± 8.8 15.66 ± 0.03 12.54 ± 0.02 2.50 ± 0.22 1.90 ± 0.17 Hájkova muš. reneta/Ti 124.2 ± 14.5 14.20 ± 0.04 11.00 ± 0.01 2.90 ± 0.14 1.93 ± 0.08 Hvězdnatá reneta/VK 119.0 ± 4.1 16.35 ± 0.03 11.60 ± 0.18 3.60 ± 0.29 1.33 ± 0.02 Jadernička moravská/VK 88.2 ± 4.0 7.57 ± 0.13 13.30 ± 0.22 1.50 ± 0.27 2.84 ± 0.14 James Grieve/Ti 147.5 ± 8.4 16.22 ± 0.02 14.05 ± 0.01 1.68 ± 0.15 2.02 ± 0.07 Jeptiška/Ti 155.7 ± 7.4 12.37 ± 0.04 11.20 ± 0.01 5.40 ± 0.57 1.15 ± 0.05 Kalvil bílý podzimní/Ti 161.4 ± 10.1 12.32 ± 0.02 12.01 ± 0.01 5.00 ± 0.50 1.92 ± 0.04 Krasokvět/Ti 170.1 ± 18.8 14.57 ± 0.06 13.89 ± 0.02 3.10 ± 0.29 1.85 ± 0.11 Krátkostopka králov./Ti 169.1 ± 7.0 11.84 ± 0.06 11.80 ± 0.22 3.20 ± 0.24 2.80 ± 0.09 Lebelovo/VK 165.0 ± 17.1 12.87 ± 0.10 11.60 ± 0.08 4.90 ± 0.54 1.59 ± 0.12 Lebelovo/Ti 200.7 ± 44.7 13.10 ± 0.03 11.75 ± 0.02 3.30 ± 0.36 1.11 ± 0.10 Lecar/Ti 100.5 ± 6.2 12.30 ± 0.03 13.61 ± 0.01 5.20 ± 0.08 2.56 ± 0.03 Limburské/Ti 198.8 ± 9.3 10.39 ± 0.02 13.14 ± 0.01 1.50 ± 0.29 2.09 ± 0.13 Matčino/VK 135.1 ± 11.6 12.42 ± 1.00 12.00 ± 0.14 1.60 ± 0.20 1.88 ± 0.06 Matčino/Ti 115.4 ± 5.8 14.21 ± 0.07 12.15 ± 0.01 1.90 ± 0.39 2.01 ± 0.11 Ontario/Ti 125.8 ± 8.9 14.89 ± 0.03 13.57 ± 0.01 1.80 ± 0.08 1.88 ± 0.05 Panenské české/Ti 111.2 ± 10.8 11.84 ± 0.03 14.86 ± 0.02 3.10 ± 0.14 1.18 ± 0.07 Parména zlatá/Ti 91.1 ± 5.4 16.13 ± 0.02 12.17 ± 0.01 3.00 ± 0.28 1.18 ± 0.05 Sikulské/Ti 236.3 ± 39.0 16.51 ± 0.02 13.84 ± 0.01 2.20 ± 0.23 1.63 ± 0.11 Sláva světa/Ti 153.0 ± 8.4 13.64 ± 0.08 11.05 ± 0.01 3.10 ± 0.47 1.87 ± 0.05 Spartan/Ti 82.8 ± 6.8 13.95 ± 0.01 13.90 ± 0.01 2.28 ± 0.32 2.40 ± 0.04 Starkrimson/VK 54.1 ± 2.4 16.35 ± 0.01 16.10 ± 0.41 1.70 ± 0.24 1.52 ± 0.12 Strýmka/Ti 111.3 ± 7.5 11.58 ± 0.08 15.68 ± 0.01 1.80 ± 0.29 3.26 ± 0.17 Šarlatka boračská/Ti 82.9 ± 5.2 14.51 ± 0.03 12.88 ± 0.02 1.90 ± 0.24 1.86 ± 0.02 Ušlechtilé žluté/Ti 95.5 ± 5.9 15.33 ± 0.02 11.85 ± 0.02 4.00 ± 0.37 1.58 ± 0.06 Vilémovo/VK 134.7 ± 5.7 11.84 ± 0.05 11.40 ± 0.08 2.60 ± 0.14 2.02 ± 0.10 Vilémovo/Ti 123.5 ± 6.9 15.64 ± 0.04 12.15 ± 0.02 3.50 ± 0.32 2.55 ± 0.05 *VK = Valašské Klobouky, Ti = Tišnov; **mean ± standard deviation (n = 15) Assessment of nutritional parameters of native apple cultivars as new gene sources 31 růžové’), in peels these values ranged from 19.11 (again the variety ’Vilémovo’) to 56.65 mmol of trolox.kg−1 FM (again the variety ’Bernské růžové’); the obtained results were statistically signifi cant (Tab. III). Statistically signifi cant minimum contents of vitamin C were found out in apples of the varieties ’Jadernička moravská’ and ’Starkrimson’ (Tab. V). On the other hand, statistically signifi cant maximum contents of vitamin C were found out in apples of the variety ’Albrechtovo’ (13.55 mg.kg−1 FM). When estimating correlations existing between the content of ascorbic acid and the total antioxidant capacity, the calculated correlation coeffi cients for the fl esh and peel were r = 0.7806 and r = 0.4995, respectively (Fig. 6). II: Content of elements in apple cultivars (n = 15) Cultivar NPKCaMgNa (ppm) (ppm) (ppm) (ppm) (ppm) (ppb) Albrechtovo/VK* 3.68 ± 0.15 1.05 ± 0.06 9.10 ± 0.14 0.52 ± 0.01 0.34 ± 0.04 65 ± 17 Baumannova reneta/Ti 3.90 ± 0.14 1.05 ± 0.03 7.10 ± 0.22 0.69 ± 0.05 0.34 ± 0.01 70 ± 8 Bernské růžové/VK 3.08 ± 0.10 0.87 ± 0.08 6.30 ± 0.29 0.50 ± 0.01 0.23 ± 0.03 60 ± 8 Bláhovo oranžové/Ti 3.83 ± 0.22 1.07 ± 0.04 7.70 ± 0.35 0.70 ± 0.04 0.39 ± 0.03 100 ± 8 Boikovo/Ti 4.00 ± 0.08 0.97 ± 0.02 9.70 ± 0.22 0.82 ± 0.01 0.40 ± 0.01 103 ± 10 Boskoopské/Ti 4.50 ± 0.12 0.99 ± 0.06 8.40 ± 0.27 0.58 ± 0.03 0.37 ± 0.01 90 ± 12 Citronové zimní/Ti 3.20 ± 0.18 0.81 ± 0.02 7.10 ± 0.29 0.55 ± 0.01 0.39 ± 0.03 88 ± 10 Coxova reneta /Ti 3.40 ± 0.08 1.04 ± 0.04 6.53 ± 0.05 0.51 ± 0.04 0.32 ± 0.01 70 ± 8 Croncelské/Ti 3.73 ± 0.54 0.88 ± 0.05 8.50 ± 0.18 0.70 ± 0.12 0.41 ± 0.02 98 ± 10 Gdánský hranáč/Ti 2.90 ± 0.24 0.85 ± 0.04 6.70 ± 0.22 0.39 ± 0.01 0.29 ± 0.02 80 ± 8 Grávštýnské/Ti 4.00 ± 0.08 0.86 ± 0.08 9.20 ± 0.18 0.40 ± 0.03 0.28 ± 0.01 60 ± 8 Gustavovo/Ti 3.28 ± 0.21 0.81 ± 0.04 9.00 ± 0.43 0.82 ± 0.02 0.32 ± 0.01 60 ± 8 Hájkova muš. reneta/Ti 2.90 ± 0.34 0.93 ± 0.08 6.90 ± 0.14 0.59 ± 0.05 0.32 ± 0.01 90 ± 8 Hvězdnatá reneta/VK 3.10 ± 0.08 0.87 ± 0.02 8.50 ± 0.36 0.48 ± 0.02 0.36 ± 0.01 68 ± 10 Jadernička moravská/VK 3.20 ± 0.14 1.07 ± 0.04 7.80 ± 0.29 0.48 ± 0.03 0.30 ± 0.01 58 ± 10 James Grieve/Ti 3.93 ± 0.10 1.04 ± 0.04 8.10 ± 0.18 0.64 ± 0.05 0.40 ± 0.02 135 ± 13 Jeptiška/Ti 3.80 ± 0.18 0.86 ± 0.02 9.50 ± 0.32 0.80 ± 0.08 0.41 ± 0.01 90 ± 8 Kalvil bílý podzimní/Ti 3.00 ± 0.16 0.88 ± 0.05 9.00 ± 0.18 0.51 ± 0.03 0.30 ± 0.02 60 ± 8 Krasokvět/Ti 3.10 ± 0.14 1.00 ± 0.04 5.80 ± 0.32 0.46 ± 0.01 0.27 ± 0.02 138 ± 5 Krátkostopka králov./Ti 4.10 ± 0.20 0.95 ± 0.04 7.20 ± 0.38 0.39 ± 0.01 0.33 ± 0.02 190 ± 14 Lebelovo/VK 3.30 ± 0.14 1.02 ± 0.03 8.10 ± 0.22 0.41 ± 0.02 0.35 ± 0.02 188 ± 5 Lebelovo/Ti 3.50 ± 0.22 0.95 ± 0.07 7.80 ± 0.29 0.41 ± 0.01 0.34 ± 0.01 140 ± 14 Lecar/Ti 2.80 ± 0.18 0.89 ± 0.03 5.83 ± 0.05 0.48 ± 0.02 0.30 ± 0.02 60 ± 8 Limburské/Ti 4.20 ± 0.24 0.90 ± 0.03 7.50 ± 0.33 0.53 ± 0.05 0.30 ± 0.02 90 ± 8 Matčino/VK 3.30 ± 0.14 1.01 ± 0.05 7.80 ± 0.32 0.67 ± 0.01 0.34 ± 0.03 188 ± 10 Matčino/Ti 3.50 ± 0.41 0.98 ± 0.03 8.20 ± 0.18 0.75 ± 0.02 0.32 ± 0.02 150 ± 8 Ontario/Ti 3.70 ± 0.08 0.98 ± 0.03 8.80 ± 0.36 0.68 ± 0.02 0.36 ± 0.03 170 ± 12 Panenské české/Ti 4.00 ± 0.26 0.88 ± 0.03 8.10 ± 0.48 0.75 ± 0.04 0.35 ± 0.03 170 ± 16 Parména zlatá/Ti 3.00 ± 0.14 0.94 ± 0.03 6.50 ± 0.18 0.47 ± 0.03 0.33 ± 0.02 68 ± 13 Sikulské/Ti 3.00 ± 0.08 0.95 ± 0.04 6.10 ± 0.29 0.59 ± 0.01 0.33 ± 0.01 70 ± 8 Sláva světa/Ti 2.80 ± 0.24 0.89 ± 0.05 6.00 ± 0.32 0.51 ± 0.04 0.32 ± 0.02 48 ± 5 Spartan/Ti 3.90 ± 0.14 1.01 ± 0.06 8.80 ± 0.53 0.66 ± 0.05 0.31 ± 0.01 118 ± 10 Starkrimson/VK 3.30 ± 0.32 0.98 ± 0.05 6.30 ± 0.14 0.54 ± 0.05 0.29 ± 0.06 90 ± 8 Strýmka/Ti 3.70 ± 0.59 1.02 ± 0.06 9.20 ± 0.32 0.63 ± 0.03 0.30 ± 0.02 120 ± 8 Šarlatka boračská/Ti 3.40 ± 0.16 0.90 ± 0.04 6.70 ± 0.36 0.58 ± 0.01 0.28 ± 0.03 70 ± 8 Ušlechtilé zluté/Ti 3.00 ± 0.32 0.81 ± 0.03 7.20 ± 0.92 0.60 ± 0.03 0.33 ± 0.02 80 ± 8 Vilémovo/VK 3.30 ± 0.12 0.87 ± 0.05 6.30 ± 0.14 0.35 ± 0.01 0.27 ± 0.02 65 ± 13 Vilémovo/Ti 3.50 ± 0.18 0.90 ± 0.12 7.20 ± 0.42 0.45 ± 0.02 0.33 ± 0.01 70 ± 8 *VK = Valašské Klobouky, Ti = Tišnov; ***mean ± standard deviation (n = 15) 32 J. Balík, O. Rop, J. Mlček, P. Híc, M. Horák, V. Řezníček DISCUSSION Today, apple trees are the most popular and the most grown core fruit species in Europe. As far as apples as fruit are concerned, their taste and their possible utilization for nutritional purposes represent the most valued characteristics. However, all properties of fruit which infl uence marketability of apples are of importance as well. What is also important is their capability to tolerate transport and storage conditions (Goland and Bauer, 2004). Although it is possible to fi nd out tens of various apple tree varieties in Europe, only some of them were purposefully bred and selected in the past (Radicato et al., 1995) and the same concerns also for example pears (Benitez, 1998). A further propagation of local varieties is prevented above all by the fact that their sensory and technological properties are not as good as those of purposefully bred and selected ones (Kuhn et al., 2003) although their local importance may be rather considerable (K, Ca, Na) -4 -3 -2 -1 0 1 2 3 4 -5 -4 -3 -2 -1 0 1 2 3 4 Komponenta 1 PC2 (20.3%) PC1 (25.2%) A B C D E F G H I(Fruit weight) (Dry mass, Mg) (Soluble solid content, N, P) (Pectin) (Titratable acidity) 1: Principal component analysis of all observed analytic data (A = Bernské růžové, B = Jadernička moravská, C = Coxova reneta, D = Strýmka, E = Spartan, F = Boikovo, G = Croncelské, H = Jeptiška, I = Citronové zimní) 30 80 130 180 230 280 Starkrinson/VK Gdánský hranáþ/Ti Bernské rĤžové/VK Spartan/Ti Šarlatka boraþská/Ti Jaderniþka moravská/VK Bláhovo oranžové/Ti Coxova reneta /Ti Parména zlatá/Ti Ušlechtilé žluté/Ti Albrechtovo/VK Gustavovo/Ti Lecar/Ti Boikovo/Ti Panenské þeské/Ti Strýmka/Ti Matþino/Ti HvČzdnatá reneta/VK Vilémovo/Ti Hájkova muš. reneta/Ti Ontario/Ti Grávštýnské/Ti Vilémovo/VK Matþino/VK Boskoopské/Ti Baumannova reneta/Ti James Grieve/Ti Sláva svČta/Ti Citronové zimní/Ti Jeptiška/Ti Kalvil bílý podzimní/Ti Lebelovo/VK Croncelské/Ti Krátkostopka králov./Ti KrasokvČt/Ti Limburské/Ti Lebelovo/Ti Sikulské/Ti Fruit weight (g) 2: Mean of fruit weight and Tukey HSD intervals (P = 0.95; n = 15) depending on apple cultivars Assessment of nutritional parameters of native apple cultivars as new gene sources 33 10.0 10.5 11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0 16.5 Hájkova muš. reneta/Ti Sláva svČta/Ti Citronové zimní/Ti Gdánský hranáþ/Ti Jeptiška/Ti Bernské rĤžové/VK Vilémovo/VK HvČzdnatá reneta/VK Lebelovo/VK Lebelovo/Ti Krátkostopka králov./Ti Ušlechtilé žluté/Ti Matþino/VK Kalvil bílý podzimní/Ti Matþino/Ti Vilémovo/Ti Parména zlatá/Ti Boskoopské/Ti Gustavovo/Ti Šarlatka boraþská/Ti Bláhovo oranžové/Ti Limburské/Ti Boikovo/Ti Jaderniþka moravská/VK Albrechtovo/VK Ontario/Ti Lecar/Ti Sikulské/Ti Baumannova reneta/Ti Grávštýnské/Ti KrasokvČt/Ti Spartan/Ti James Grieve/Ti Croncelské/Ti Coxova reneta /Ti Panenské þeské/Ti Strýmka/Ti Starkrinson/VK Soluble solid content (%) 3: Mean of soluble solid content and Tukey HSD intervals (P = 0.95; n = 15) depending on apple cultivars 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Lebelovo/Ti Boikovo/Ti Croncelské/Ti Jeptiška/Ti Panenské Parména HvČzdnatá Grávštýnské/Ti Citronové Starkrinson/VK Ušlechtilé Lebelovo/VK Sikulské/Ti Bláhovo KrasokvČt/Ti Šarlatka Sláva svČta/Ti Matþino/VK Ontario/Ti Gustavovo/Ti Kalvil bílý Hájkova muš. Albrechtovo/VK Matþino/Ti James Vilémovo/VK Limburské/Ti Coxova reneta Spartan/Ti Boskoopské/Ti Vilémovo/Ti Lecar/Ti Bernské Krátkostopka Jaderniþka Gdánský Baumannova Strýmka/Ti Pectin (%) 4: Mean of pectin content and Tukey HSD intervals (P = 0.95; n = 15) depending on apple cultivars 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 KrasokvČt/Ti Lecar/Ti Sláva svČta/Ti Sikulské/Ti Bernské Starkrinson/VK Vilémovo/VK Parména Coxova reneta Gdánský Šarlatka Hájkova muš. Baumannova Citronové Krátkostopka Ušlechtilé Vilémovo/Ti Limburské/Ti Bláhovo Jaderniþka Lebelovo/Ti Matþino/VK James Lebelovo/VK Panenské Matþino/Ti Boskoopské/Ti Croncelské/Ti HvČzdnatá Ontario/Ti Spartan/Ti Gustavovo/Ti Kalvil bílý Albrechtovo/VK Grávštýnské/Ti Strýmka/Ti Jeptiška/Ti Boikovo/Ti Potassium (ppm) 5: Mean of potassium content and Tukey HSD intervals (P = 0.95; n = 15) depending on apple cultivars 34 J. Balík, O. Rop, J. Mlček, P. Híc, M. Horák, V. Řezníček (Goland and Bauer, 2004). Local varieties represent a rich source of genetically conditioned properties, i.e. not only their resistance to diseases but also some – until now – unknown and not described possibilities of a unique technological utilisation and specifi c taste and other sensory properties (Monschein et al., 2006). Although it is necessary to consider some diff erences in their chemical composition, resulting from the year of harvest and infl uenced by the locality (Little and Tailor, 1981), it can be said that local varieties are well adapted to local climatic conditions (Melounová et al., 2004). It is also known that there are only slight diff erences in the contents of individual chemical compounds when comparing individual varieties and that they are determined by the genetic uniqueness of each of them (Goland and Bauer, 2004). In individual apple tree varieties the values of measured chemical characteristics ranged within the limits mentioned in tables used in alimentary industry (Kováčiková et al., 1997; Kopec, 1998). Nevertheless, individual varieties showed variability, III: Antioxidant capacity in peel of selected apple cultivars Cultivar Mean *HSD interval Homogeneous groups (mmol trolox.kg−1 FM) Jadernička moravská 19.11 10.16–28.03 A Lebelovo 25.45 13.50–37.41 AB Vilémovo 27.55 15.59–39.50 AB Starkrimson 33.44 21.49–45.39 ABC Hvězdnatá reneta 40.10 28.15–52.06 BC Albrechtovo 41.73 29.78–53.69 BC Matčino 46.55 34.60–58.51 BC Bernské růžové 56.65 44.69–68.60 C Total mean 36.32 *high standard deviation (Tukey, P = 0.95, n = 5) IV: Antioxidant capacity in fl esh of selected apple cultivars Cultivar Mean *HSD interval Homogeneous groups (mmol trolox.kg−1 FM) Vilémovo 4.02 0.70–7.33 A Matčino 4.20 0.88–7.51 A Starkrimson 4.49 1.18–7.81 A Jadernička moravská 4.82 1.51–8.13 A Hvězdnatá reneta 5.73 2.42–9.05 A Albrechtovo 6.00 2.68–9.31 A Lebelovo 6.12 2.81–9.44 A Bernské růžové 6.59 3.27–9.90 A Total mean 5.25 *high standard deviation (Tukey, P = 0.95, n = 5) V: L-ascorbic acid content in selected apple cultivars (mg.100 g−1) Cultivar Mean *HSD interval Homogeneous groups (mg.100 g−1 FM) Jadernička moravská 9.14 8.83–9.45 A Starkrimson 9.15 8.84–9.46 A Matčino 10.36 10.05–10.67 B Vilémovo 11.20 10.89–11.51 C Hvězdnatá reneta 12.50 12.1 9–12.81 D Lebelovo 12.65 12.34–12.96 D Bernské růžové 12.92 12.61–13.23 D Albrechtovo 13.55 13.24–13.86 E Total mean 11.43 *high standard deviation (Tukey, P = 0.95, n = 15) Assessment of nutritional parameters of native apple cultivars as new gene sources 35 which is presented in Tabs. I–V and Figs. 1–6. The similarity of chemical characteristics of individual apple varieties and their general affi nity in the stage of consume ripeness is expressed by means of cluster analysis. When evaluating individual clusters it is obvious that the most marked characteristic is the kinship based on the stage of consume ripeness (Tetera, 2006). Of chemical parameters under study, the most important are the following: the soluble solid content, the content of acids and the content of pectins (Rop et al., 2010a). In apples, the content of organic acids is represented mainly (90%) by malic acid (Kyzlink, 1990). However, the presence of some macroelements (e.g. nitrogen) is manifested by an increase in the content of citric acid and a decrease in the malic acid (Jakopic et al., 2007). Among other organic acids it is possible to fi nd out malonic, shikimic, and fumaric acids, some amino acids (with predominating aspartic acid) and polyphenolic chlorogenic acid (Stampar et al., 2002). So, for example, it was found out, similarly as Suni et al. (2000) noticed, that the content of acids in the variety ’Boskoopské’ was low (1.9 g.kg−1 FM). On the other hand, the variety ’Citronové zimní’ contained 6.1 g.kg−1 FM of organic acids. In the variety ’Boskoopské’, the content of nitrogen in dry matter was also high (4.50 ppm of DM). Wolf et al. (2007) mentioned similar contents of nitrogen in apples (up to 5.00 ppm). Apples are important above all due to their content of pectins, which predetermine them for the processing to fruit spreads thanks to their capability of gelifi cation in presence of saccharose under conditions of low pH (Kyzlink, 1990). Of other core fruit species a high content of pectins can be found for example in quinces (Baker, 1997), which may contain as much as 3% of pectins in FM (Kováčiková et al., 1997). In apples, however, the average content of pectins is about 1.1% FM (Kopec, 1998). In our experiments, this value was found out in varieties with the lowest contents of pectin compounds (Tab. I). The variety ’Strýmka’, which contained as much as 3.26% of pectins in FM, was an interesting exception. This variety is frequently used in the region of the White Carpathians (Tetera, 2006). However, this does not have to be an extreme value because Bailoni et al. (2005) mentioned that some local varieties may contain as much as 5% of pectins in FM. As compared with other species of core fruit, apples show relatively high contents of mineral substances (Kovacs and Meresz, 2004). In core fruit, potassium is the most abundant macroelement (Kováčiková et al., 1997). In our experiments, the variety ’Boikovo’ contained as much as 9.70 ppm of this element in dry matter. Although some commercial varieties (e.g. ’Ontario’ or ’Spartan’) showed also high contents of macroelements, some typically local varieties contained more than 9.00 ppm of potassium. Also the contents of other elements (phosphorus, magnesium, sodium) were relatively high in local varieties, even when compared with tabular values (Kováčiková et al., 1997; Kopec, 1998). Health benefi ts resulting from the consumption of apples due to their high content of minerals was emphasized also by several authors, e.g. by Biedrzycka (2008). It is well known that local varieties show very o en higher contents of minerals than the commercial ones (Iwane, 1991). The content of vitamin C in crops is most infl uenced by variety and year of cultivation Valšíková et al., 2010). The contents of vitamin C and antioxidant capacity were measured in apples showing the consume ripeness and originating from the locality Valašské Klobouky. As one can see in Tabs. III and IV, antioxidant capacity of peels was explicitly higher than of the fl esh. This fact was R =0.49948 P = 0.10378 R = 0.78055 P = 0.01113 0 1 2 3 4 5 6 7 20 25 30 35 40 45 50 55 60 9.14 9.15 10.36 11.20 12.50 12.65 12.92 13.55 TAC in flesh (mmol trolox . kg -1 ) TAC in peel (mmol trolox . kg -1 ) L-ascorbic acid (mg .100g -1 ) peel flesh peel 6: Correlation analysis between antioxidant capacity in peel (flesh) of apple cultivar and L-ascorbic content