Beyhan, Ömer; Aktaş, Mehmet; Yilmaz, Necmettin; Şimşek, Nurten; Gerçekçioǧlu, Resul

This study was conducted to determine the fatty acid composition of Picantili, Ferraduel, Drake and Nonpareil commercial almond species (Prunus amygdalus L.) cultivated in Tokat province under dry conditions; of genotype ST-11 and YD-2 selected from Tokat region; and of 101-13, 300-1, 17-4 sweet almond species, selected from the Aegean region. The percentage and composition of the fatty acids of the samples were determined by gas chromatography. The amounts of oleic acid, linoleic acid, palmitic acid and stearic acid, respectively, were found to be higher than the other fatty acids in all genotypes. These fatty acids were similar in amounts and little change was observed between the genotypes. These values were determined to range from 57.46 to 68.65%, 11.77 to 25.15%, 5.06 to 7.26% and 1.26 to 2.41%, respectively. However, genotype 17-4 included more docosaheaenoic acid (DHA), pentadecanoic and nervonic acids than the other genotypes. According to these results, it can be suggested that the fatty acid composition of genotypes were not changed very significantly although there are some differences between samples as percentage. Genotype 17-4 is more heavily affected by dry climatic conditions than other genotypes.

Koksal, Ekrem; Bursal, Ercan; Dikici, Emrah; Tozoglu, Fatih; Gulcin, Ilhami

The purpose of this study was to evaluate antioxidant activities of water extract of Melissa officinalis (WEM) and ethanol extract of M. officinalis (EEM), comparatively. The WEM and EEM were evaluated for their radical scavenging activities by means of the DPPH and DMPD assays. WEM scavenged radicals effectively with IC 50 values of 31.4 μg/mL for DPPH free radical and 60.5 μg /mL for DMPD cation radical. Similarly, EEM scavenged radicals effectively with IC 50 values of 202.7 μg/mL for DPPH free radical and 120.9 μg/mL for DMPD cation radical. Also, total reducing power of WEM was found higher than EEM with both potassium ferricyanide reduction (FRAP) and cupric ions reduction capacity methods (CUPRAC). The present study showed that WEM have effective antioxidant and radical scavenging activities as compared to EEM.

Şişecioǧlu, Melda; Gülçin, Ilhami; Çankaya, Murat; Atasever, Ali; Şehitoǧlu, M. Hilal; Kaya, Habibe Budak; Özdemir, Hasan

Peroxidases (EC 1.11.1.7; donor: hydrogen peroxide oxidoreductase) are part of a large group of enzymes associated with cell wall biosynthesis, response to injury, disease, resistance and wound repair. They catalyze the oxidation of various electron donor substrates such as phenols and aromatic amines in the presence of hydrogen peroxide. In the present study, peroxidase, a primer antioxidant enzyme, was purified 9.7 fold from Turkish black radish (Raphanus sativus L.) in a yield of 2% by ammonium sulphate precipitation, dialysis and CM-Sephadex ion exchange chromatography. To check the enzyme purity, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed and a single band was observed. The substrate specificity of peroxidase was investigated using guaiacol (2-methoxyphenol). Optimum pH, optimum temperature, optimum ionic strength, stable pH, stable temperature and thermal inactivation conditions were determined for guaiacol / H 2O 2 substrate pattern. These kinetic properties were found to be 6.0, 30°C, 1.0 M, 9.0, and 60°C, respectively. The molecular weight (M w) of the enzyme was found to be 66 kDa by sodium dodecyl sulphatepolyacrylamide gel electrophoresis (SDS - PAGE) method. Native polyacrylamide gel electrophoresis (Native-PAGE) was performed for isoenzyme determination and a single band was observed. K m and V max values were calculated from Lineweaver-Burk graphs.