Cemil İşlek

High hydrostatic pressure extraction of phenolic compounds from Maclura pomifera fruits

High hydrostatic pressure processing (HHPP) is a food processing method, in which food is subjected to the elevated pressure which is mostly between 100 to 800 MPa. HHPP is seen not only in food engineering, but also have other application areas, such as extraction of active ingredients from natural biomaterials. In this study, several extraction conditions such as two different solvents [methanol and solvent cocktail (dH 2 O:ethanol:methanol:acetone:CH2Cl2 - 1:2.5:2.5:2:2)], two different pressures for high hydrostatic pressure extraction (HHPE) (250 and 500 MPa), three different extraction methods (shaking at room temperature, soxhlet extractor and HHPE) and different extraction times for each extraction method (10 min for HHPE, 2 h for shaking and 14 h for soxhlet extraction) were used in order to extract phenolic compounds from Maclura pomifera fruits. The highest amount of phenolic compounds (913.173 μg gallic acid equivalent (GAE/mL) was observed in HHPE at 500 MPa using solvent cocktail, where the lowest amount (316.877 μg GAE/mL) was in soxhlet extraction using methanol. In terms of extraction efficiency, the highest amount of extraction is seen in the shortest time period. It was observed that HHPE in solvent cocktail was the most effective method when compared to the other methods tested. Key words : Maclura pomifera , Osage orange, hedge apple, phenolic compound, high hydrostatic pressure extraction.

Spermine and its interaction with proline induce resistance to the root rot pathogen Phytophthora capsici in pepper ( Capsicum annuum )

The root rot pathogen Phytophthora capsici can severely damage production of peppers (Capsicum annuum). This study examined the effect of exogenous spermine and spermine in combination with proline on disease severity in pepper inoculated with P. capsici, as well as the effect of the treatments on P. capsici growth and zoospore development. Peroxidase, catalase, and polyphenol oxidase activity, the levels of phenolic compounds, malondialdehyde (MDA), and hydrogen peroxide (H2O2), and fresh and dry weight were measured on the 3rd, 5th, and 7th days after P. capsici infection. Disease severity and size of the necrotic lesions increased with the degree of injury caused by the pathogen and decreased in resistant varieties. The cultivar CM-334 exhibited the highest resistance to P. capsici followed by Amazon F1 whereas other genotypes were susceptible to the disease. Treatments with spermine and spermine + proline prior to inoculation decreased the severity of disease, the length of the necrotic lesions, and the MDA and H2O2 levels in all genotypes, and increased peroxidase, catalase, and polyphenol oxidase activity, the total level of phenolics, and fresh and dry weight, when compared to the untreated, inoculated plants. In addition, 1 mM spermine, 1 mM spermine + 1 mM proline, and 1 mM spermine + 10 mM proline decreased colony growth of P. capsici and zoospore production. This study showed that spermine and spermine + proline induced defense responses and increased resistance to P. capsici infection in pepper.

The effect of high hydrostatic pressure on the physiological and biochemical properties of pepper (Capsicum annuum L.) seedlings

High hydrostatic pressure is a non-thermal food processing technology, which also has several successful applications in different areas besides food processing. In this study, Capsicum annuum L. (pepper) seeds are subjected to 50, 100, 200 and 300 MPa pressure for 5 min at 25°C and the seedlings of HHP processed seeds are used to compare percentage of seed germination and biochemical properties such as chlorophyll a, b and a/b, proline content, total protein, carotenoid, malondialdehyde, glucose, fructose and phenolic compounds concentrations. As a result of the study, it was observed that there are remarkable changes in terms of biochemical properties especially for seedlings, whose seeds were pressurized at 200 and 300 MPa. More detailed studies are needed to put forward the mechanism behind the changes in biochemical properties.

Effect of high hydrostatic pressure on seed germination, microbial quality, anatomy–morphology and physiological characteristics of garden cress (Lepidium sativum) seedlings

High hydrostatic pressure is a non-thermal food processing technology that is found to increase the percentage of germination, decrease the germination time and improve the microbial quality of seeds. In this study, pressures of 100–400 MPa for 10 min at 30°C are used to compare the percentage of germination, the microbial quality of seeds, chlorophyll a and b, and total phenolic compounds concentrations in seedlings, and the anatomy–morphology characteristics of garden cress. Enhanced reductions of total aerobic mesophilic bacteria, total and fecal coliforms, and yeast and mould populations in seeds were observed, especially at 300 MPa. In addition, the percentage of germination, chlorophyll content and phenolic compounds concentrations, fresh and dry weights, and hypocotyl lengths of the seedlings are higher than those of all samples, where the percentage of germination is equal to controls but higher than other samples, and radicula length is lower than controls but higher than others.

Kadmiyumun biber (Capsicum annuum L.) fidelerinde fenilalanin amonyum liyaz aktivitesi ve lipid peroksidasyonu üzerine etkisi

In this study, the effect on differrent concentrations (20, 40, 80µM ve 100 µM CdCl2 ) of cadmium (CdCl2) on the activity of phenylalanine ammonia-lyase (PAL) and lipid peroxidation amount in leaf and stem of Kahramanmaras- Hot (Capsicum annum L.) pepper seedlings were researched. Activity of phenylalanine ammonia-lyase (PAL), the first enzyme in the phenylpropanoid biosynthetic pathway, was increased at 2 and 4 days in KM-Hot plants exposed to CdCl2 stress. The highest PAL activity was detected in 20 μM CdCl2 application, on the four day after the application in the leaves of KM-Hot pepper. Moreover, it was observed that treatment of pepper with Cd led to an increased the rate of lipid peroxidation (which is indicated by increasing MDA content) in the leaf and stem tissues. The highest MDA content was detected in 80 μM CdCl2 application, on the four day after the application in the leaf tissues. These results suggest that the activation of PAL may be associated with increased production of MDA