International Journal of Horticultural Science 2011, 17 (1 –2): 63 –68. Agroinform Publishing House, Budapest, Printed in Hungary ISSN 1585-0404 Composition and storage of pear cultivars from Nagykanizsa Tóth-Markus, M. 1, Bánáti, D. 1, Adányi, N. 1, Boross, F. 1, Konrád-Németh, C. 2, Szabó, Z., 3 Soltész, M. 4 & Nyéki, J. 3 1Central Food Research Institute, Hungary, H-1022 Budapest, Herman Ottó Street 15 tel.: +36 1 3558838 e-mail: [email protected] 2Gyümölcskert cPlc Hungary, H-8900 Nagykanizsa, Csengery street 90 3University of Debrecen Centre for Agricultural and Applied Economic Sciences, H-4032 Debrecen, Böszörményi út 138., Hungary 4Collage of Kecskemét, Faculty of Horticulture, H-6000 Kecskemét, Erdei Ferenc tér 1 –3. Summary: The composition of five pear varieties (‘Abate Fètel’, ‘Bosc’, ‘Williams’, ‘Conference’, ‘Packham’s Triumph’) grown in Nagy- kanizsa was investigated in three consecutive years (2008, 2009, 2010). A storage experiment was performed in 2008. Four winter pear cultivars were kept in an ULO store for four months and their parameters measured after two and four months. The parameters tested were: size, weight, water soluble solids, titratable acidity, glucose, fructose, sucrose, water soluble pectin, total polyphenols, free radical scavenging capacity, copper and zinc content. The fruits of ‘Conference’ and ‘Bosc’ varieties were found to contain the highest sucrose and total sugar content, while ‘Abate Fétel’ had the lowest sucrose and highest glucose levels among cultivars tested. ‘Williams’ pear was the most acidic. Brix, total sugar, sucrose and water soluble pectin were decreased during storage. Titratable acidity slightly decreased in fruits of Conference pear. Polyphenols and free radical scavenging capacity did not show a significant change during storage . Keywords: pear, storage, sugar, acid, polyphenol, antioxidant capacity Introduction from 0.187% to 0.116%, while polyphenolic compounds showed a temporary increase in the first two weeks, and a The market value of pear is determined primarily by size, slight decrease during two months, depending on weight, appearance, consistency and taste. Although many temperature. Morvai and Molnár-Perl (1992) reported the results on fruit sugars, acids and polyphenols in different growth of acids (including ascorbic), sugars and sorbitol cultivars has been published, there are few studies on change during storage of Bosc pear, but the duration and of composition of pear during storage ( Morvai & Molnár- circumstances are not known. Perl , 1992, Elgar et al ., 1997). Data on cultivars grown in our country are mainly available in Hungarian. Our aim was to fill this gap. Materials and methods According to literature data shown in Table 1 the main sugars of pear are fructose, glucose and sucrose. The values Materials are given for 1 kg fresh weight. Hudina and Štampar (2000) determined sugars and acids ‘Abate Fètel’ was grown in orchard of Gyümölcskert in 18, European and Asian pear cultivars grown in Slovenia, cPlc. at Szepetnek-Bánfapuszta. The area is located 15 km including all those studied in present paper. Colaric and co- west from Nagykanizsa, with a loamy brown forest soil. The workers (2006, 2007) studied sugars, acids and phenolic 7-hectare field, where the ‘Abate Fètel’ rows are grown, is an compounds in ‘Williams’ and ‘Conference’ pear. They intensive pear orchard, equipped with irrigator. It was detected chlorogenic acid, syringic acid, epicatechin, planted in 1997-98 with a spacing of 4×1.4, grafted on catechin, sinapic and vanillic acid with chlorogenic acid quince ( Cydonia oblonga ) rootstock. An affinity trouble is being dominating. Main organic acids are malic and citric, presumed, which seems to be proven by the way and extent with shikimic and fumaric existing as minor compounds. of tree dying. The average yield in 2008 was 12.6 kg/tree. Pear needs suitable post-harvest storage to assure a good ‘Abate Fètel’ is characterised with a very weak fertility, thus transportability and distribution. Elgar et al. (1997) having a low yield and a large size of fruits. investigated fruit from two winter pear cultivars stored for 20 The other cultivars tested were grown at the Feketesár weeks at –0.5 °C. Titratable acidity of ripened fruit decreased Orchard of Gyümölcskert cPlc. The area is located 15 km with advanced storage: In case of ‘Bosc’ the acidity changed south from Nagykanizsa, with a non-calcareous, sandy 64 Tóth-Markus, M., Bánáti, D., Adányi, N., Boross, F., Konrád-Németh, C., Szabó, Z., Soltész, M. & Nyéki, J. Table 1: Sugars, acids and polyphenols in pears Total Glucose Fructose Sucrose Citric acid Malic acid Total acid Author, date Cultivar polyphenol (g/kg) (g/kg) (g/kg) (g/kg) (g/kg) (g/kg) (mg/kg) Fourie et al., 1991 Bosc 13.6 49.9 30.9 Morvai & Molnár-Perl 1992 Bosc 19.9 55 6.1 0.6 2.6 SOUCI et al, 2000 not given 15 –16.9 60.7 –77 12.4 –25 1.4 1.7 USDA database not given 27.6 62.3 7.8 fineli database not given 20 42 8 4 Williams 4.8 39.9 34 1.7 1.1 Conference 4.9 23.7 11.3 0 2.3 Packham 11.6 34.7 5.3 0.4 3.2 Hudina et al., 2000 Fétel 16.3 43.6 6.6 0.4 3.2 Bosc 10.5 42.5 21.6 0.1 4.1 Packham 18.2 56.9 5.3 Yasunori & Iki, 2002 Williams 167 Colaric et al., 2006 Williams 9.42 73.5 7.94 max 3.05 max 2.24 447 –616 Colaric et al., 2007 Conference 7.63 –14.75 48.5 –76 6.6 –18.53 0.21 –0.22 1.97 –4.25 162 –231 humic soil. The pear orchard is cca 83 hectares, young kept about three to four months in store. Controlled plantation, planted in several phases (1997, 1999, 2000, atmosphere values were as follows: O 2 level: 3.0–5.0%, CO 2 2001, and 2003). The biennial bearing characterizing pome level: 0.9 –1.0% , temperature: –0.5–0.0 °C fruits was present in 2008 to a small extent. The average crop The free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) yield was 37 –45 kg in 2008 in fields planted in 1997 –1999, and standard Trolox, (6-hydroxy-2,5,7,8-tetramethyl- 27 –35 kg in fields planted in 2000 –2001, while less than 5 kg cromane-2-carboxylic acid) were obtained from Fluka in field planted in 2003. (Buchs, Switzerland) . Other reagents were of analytical ‘Bosc ’: planted in 1997, 1999, 2000, 2001, 2003, spacing grade and purchased from Reanal (Budapest, Hungary). 6×3 m or 5×3 m on a wild pear, ( Pyrus pyraster ), Farold 69- 87 or Pyrodwarf rootstock, Crown shape: free spindle. Methods used Produces few flowers, hardly drops any of them. Bosc exhibits a constant yield, fruits have always large size. Pear fruits were washed and then the size and weight of ‘Williams’ pear: planted in 1997, 1999, 2000, 2001, 50 fruits was measured according to Hungarian Standard 2003, spacing 6×3 m or 5×3 m on a wild pear, ( Pyrus MSZ 967-1:1982. From approximately five kg sample one pyraster ), Farold 69 –87 or Pyrodwarf rootstock, Crown kg optimally ripened, sound fruit was selected, core removed shape: free spindle. It brings many flowers, covering almost and disintegrated unpeeled using a Waring (Torrington, the whole tree, but drops much of it. This cultivar is also able USA) blender. The blended fruit sample was used in the for regular production different measurements and chemical analyses. ‘Packham’s Triumph’: planted in: 1997, 2000, 2001, Soluble solids, titratable acidity (mg/kg) total polyphenols Spacing: 6×3 m or 5×3 m on a wild pear ( Pyrus pyraster ), (mg/kg as gallic acid equivalent), free radical scavenging Farold 69 –87 or Pyrodwarf rootstock. Crown shape: free activity (TEAC: mmol/kg), copper and zinc (mg/kg) were spindle. One of parents is ‘Williams’ pear, so it has similar measured as described previously ( Tóth-Markus et al., 2010). characteristics in flowering and bearing. Glucose, fructose and sucrose were determined enzymatically ‘Conference’: planted in 1999. Spacing 5×3 m on a according to Hungarian standards MSZ EN 1140 and MSZ Farold 69 –87 rootstock, crown shape: free spindle. This EN 12146. The water soluble pectin was measured from the cultivar is able to bring a high crop yield, but it is liable to five-fold diluted pear puree according to IFU 26. Calibration biennial bearing. It is characterised by parthenocarp fruit was performed with galacturonic acid. (Precision of the production, often even the core is vestigial. In 2008 method within laboratory is approximately 10%.) ‘Conference’ brought nice large size fruits at Feketesár. The values from chemical analyses were fresh weight- Storage: Gyümölcskert cPlc performs pear storage in its related and are given as means and standard deviation of own ULO (Ultra low oxygen level) storage room. Pears were triplicate samples. Composition and storage of pear cultivars from Nagykanizsa 65 Table 2: Size and weight of pears Width avg. Greatest Smallest Length Greatest Smallest Avg. Cultivar Date (cm) width (cm) width (cm) avg (cm) length (cm) length (cm) weight (g) Williams 01.08.2008. 6.60 7.32 5.81 8.43 9.85 7.38 175 Bosc 02.09.2008. 7.31 8.68 6.53 10.51 11.95 8.52 258 Packham’s Triumph 03.09.2008. 7.04 8.11 5.95 8.45 9.98 7.32 199 Conference 30.08.2008. 6.57 7.54 5.58 9.61 11.80 8.15 184 Abate Fétel 02.09.2008. 6.74 7.45 5.95 11.40 13.90 9.22 218 Williams 01.09.2009.