Kazim Gündüz

The effects of genotype and growing conditions on antioxidant capacity, phenolic compounds, organic acid and individual sugars of strawberry

In this study, the genotypic and environmental effects for bioactive compounds in strawberries were partitioned. 13 strawberry genotypes from diverse breeding programs were selected. The genotypes were grown in three growing conditions: greenhouse (GH), plastic tunnel (PT) and open-field (OF) for two growing seasons. The results indicated that the genotypes were significantly different for most of the characteristics tested except the ferric reducing ability assay (FRAP) and Trolox-equivalent antioxidant capacity assay (TEAC) in the second growing season, while the growing conditions were only significant for total phenolic content (TPC) and fructose and total sugar content in the first growing season. Genotype had 71% and 72% of the total variance for total monomeric anthocyanin contents (TMA), while it had only 12% and 13% of the variance for TPC in the first and second year of the experiment. Genotype effect was larger than that from the growing conditions for most of the bioactive component variables in the experiment indicated that breeding for bioactive components may be successful.

Antioxidant activities and fatty acid composition of wild grown myrtle (Myrtus communis L.) fruits.

The fruits of eight myrtles, Myrtus communis L. accessions from the Mediterranean region of Turkey were evaluated for their antioxidant activities and fatty acid contents. The antioxidant activities of the fruit extracts were determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene-linoleic acid assays. The fatty acid contents of fruits were determined by using gas chromatography. The methanol extracts of fruits exhibited a high level of free radical scavenging activity. There was a wide range (74.51-91.65%) of antioxidant activity among the accessions in the β-carotene-linoleic acid assay. The amount of total phenolics (TP) was determined to be between 44.41-74.44 μg Gallic acid equivalent (GAE)/mg, on a dry weight basis. Oleic acid was the dominant fatty acid (67.07%), followed by palmitic (10.24%), and stearic acid (8.19%), respectively. These results suggest the future utilization of myrtle fruit extracts as food additives or in chemoprevention studies.

Phytochemical characterization of several hawthorn (Crataegus spp.) species sampled from the Eastern Mediterranean region of Turkey.

Background: We evaluated the total phenolic content, antioxidant capacity as well as antioxidant activity of five Crataegus species (A1, A2, Y1, Y2, Y4 accessions of Crataegus aronia var. aronia; B2, B3, B5, B6, B7, B9, Y5 accessions of C. aronia var. dentata; B10 accession of C. aronia var. minuta; Y3 accession of Crataegus orientalis var. orientalis and A3 accession of Crataegus monogyna subsp. azarella). Materials and Methods: Antioxidant activity and total phenolic content of fruits were determined by β-carotene bleaching and Folin–Ciocalteu assays. Antioxidant capacity was determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Results: C. monogyna subsp. azarella had the highest total phenol, antioxidant activity and antioxidant capacity of 55.2 mg gallic acid equivalents (GAE)/g dry weight (DW), 81.9% and 31.2%, respectively. C. aronia var. aronia was found to have the lowest total phenolic content (35.7 mg GAE/g DW). The antioxidant activities of fruit extracts increased in the order of C. orientalis var. orientalis < C. aronia var. minuta < C. aronia var. dentata < C. aronia var. aronia < C. monogyna subsp. azarella according to β-carotene/linoleic acid assay. In recent years, C. aronia var. dentata has gained importance as a commercial species in this region. B3 and B7 accessions had fruit weight more than 14 g, and considerable total phenol content, antioxidant activity and antioxidant capacity. Conclusion: This investigation shows the potential value of hawthorn fruit species as a good source of natural antioxidants and that consumption of hawthorn fruit or its products may contribute substantial amounts of antioxidants to the diet.

Relationships among Crataegus accessions sampled from Hatay, Turkey, as assessed by fruit characteristics and RAPD

The genus Crataegus known as hawthorns, is the largest genus among the Maloideae, which comprises 265 species. Turkey is one of the genetic centers of Crataegus and there are more than 20 species found in Turkey. The fruits of Crataegus are used as food and have high flavonoid, vitamin C, glycoside, anthocyanidin, saponin, tannin, and antioxidant levels. In this study, we attempted to characterize 15 Crataegus accessions sampled from Hatay, located in Eastern Mediterranean region of Turkey. The accessions belonged to several species; C. aronia (L.) DC. var. aronia, C. aronia var. dentata Browicz, C. aronia var. minuta Browicz, C. monogyna Jacq. subsp. azarella (Griseb.) Franco, and C. orientalis Pall. ex M. Bieb. var. orientalis. Fruit characteristics of the accessions exhibited considerable variation. The multivariate, principle component and cluster analyses indicated that the accessions belonged to three groups: (1) C. aronia var. arona accessions; (2) C. aronia var. dentata accessions; and, (3) C. monogyna subsp. azarella and C. orientalis var. orientalis accessions. The principle component analysis results also revealed that the first three components explained 46, 21, and 14% of the variation, comprising a total of 81%. The fruit length and width, leaf area, and soluble solids contents were highly correlated characteristics for the first three components. The 19 RAPD primers generated a total of 107 bands, where 76 of these were polymorphic. The molecular data analyses by principle coordinate and clustering showed similar results to those of pomological characteristics. There were three groups, (1) C. aronia var. arona accessions; (2) C. aronia var. dentata accession; and, (3) C. monogyna subsp. azarella. C. orientalis var. orientalis accession grouped with C. aronia var. arona accessions. Therefore, it can be concluded that, overall, the diversity patterns of pomological and molecular data, generated by RAPD, for Crataegus are in good agreement and the accessions of C. aronia var. aronia, C. aronia var. minuta, C. monogyna subsp. azarella and C. orientalis var. orientalis accessions.

Strawberry: Phytochemical Composition of Strawberry (Fragaria × ananassa)

Abstract Recent studies have focused on the nutrient and phytochemical contents of the strawberry and on factors affecting the composition of this fruit. The importance of nutritional quality of fruits is steadily increasing. People are becoming more and more aware of the need to consume healthy food for a healthy life. It is necessary to establish new growing systems to protect fruit quality characteristics as well as developing new strawberry cultivars having high quality. In fact, it is important to know the effect of growing conditions on the fruit quality of each strawberry cultivar developed by a breeding program.

Determination of vegetative and fruit characteristics of some thornless blackberry genotypes in Hatay (Turkey)

ABSTRACT The experiments were carried out during 2002 and 2003 at the Department of Horticulture, Faculty of Agriculture, Mustafa Kemal University, Hatay, Turkey. In this study, some vegetative and fruit quality attributes of eight blackberry genotypes (‘Jumbo’, ‘Chester Thornless’, ‘Black Satin’, ‘Navaho’, ‘Bursa 1’, ‘Bursa 2’, ‘Bursa 3’, ‘Bartm’) were evaluated in 2002 and 2003. The greatest cane numbers and cane lengths were recorded for ‘Bursa 2’. They were followed by ‘Bursa 3’ and ‘Chester Thornless’ in both years. Harvest periods ranged from 8 to 44 days and occurred from the middle of June until the end of August. ‘Jumbo’ and ‘Bursa 1’ were the earliest ripening cultivars. ‘Bursa 2’ had the longest harvest period. The highest yields were obtained from ‘Bursa 1,’ ‘Bursa 2’ and ‘Chester Thornless.’ ‘Jumbo’ had the largest fruits. The highest TSS/TA ratio was found in ‘Navaho’.