Ahmet A R D A Demirci | Yok (original) (raw)
Papers by Ahmet A R D A Demirci
Gida the Journal of Food, 2016
Conjugated linoleic acid (CLA) is a common term of various positional and geometric isomers of li... more Conjugated linoleic acid (CLA) is a common term of various positional and geometric isomers of linoleicacid (LA) which contains two unsaturated double bonds in the fatty acid chains. Isomers are synthesizedas an intermediate product during the bacterial biohydrogenation of LA to stearic acid in the rumen ofruminants or from the conversion of trans vaccenic acid by the ∆9-desaturase enzyme in the mammaryglands and adipose tissues. CLA isomers are found in many foods, but mainly present in meat and dairyproducts obtained from ruminant animals. Although there are diverse positive effects of CLA isomerson health, some potential concerns that can be caused by these compounds have been stated in somestudies. CLA production is not specific to rumen bacteria; it was determined that some lactic acid andpropionic acid bacteria as well as microorganisms isolated from the milk products, human and animalintestines involved in the production. Therefore, use of these microorganisms in food industr...
Business and Economic Research, 2020
This study aims to understand whether the personal traits or the environmental conditions play a ... more This study aims to understand whether the personal traits or the environmental conditions play a more significant role in entrepreneurial intentions. Since intentions are strong predictors of the behaviors, it is important to understand whether the former or the latter factor has a stronger impact on entrepreneurial dispositions. In order to understand the complex relations between entrepreneurial intentions, personality traits, and perceived environmental conditions, total number of 229 economics and business administration students at Anadolu University, Faculty of Economics and Administrative Sciences were surveyed. Results of the statistical analysis have revealed that although the majority of the individual personal traits and contextual factors are perceived as strong predictors of entrepreneurial intentions, when considered as separate holistic structures; personal traits are better predictors for entrepreneurial intentions compared to contextual factors in Turkey.
Anadolu Üniversitesi Sosyal Bilimler Dergisi, 2019
Cynicism within the organizational context has been gaining ground in the last few decades due to... more Cynicism within the organizational context has been gaining ground in the last few decades due to massive changes in how business enterprises are run. Cynicism, from the organizational perspective, refers to a multi-faceted attitude characterized by negative feelings such as distrust, frustration and contempt toward the policies and practices of organization itself. In many cases, organizational cynicism reveals itself among employees as cynical attitudes toward managers. Such type of organizational cynicism is known as management cynicism. Although there are numerous organizational and individual causes lying behind management cynicism, this study focuses on how different organizational culture profiles affect management cynicism. In this study, four-quadrant organizational culture framework developed by Cameron and Freeman (1991) was adopted to illustrate if different cultural profiles and values attributed to them have significant impact on management cynicism. This paper examines the relations between different organizational culture profiles and management cynicism based on data collected from shop floor employees of four leading vendor companies for big-sized domestic appliance manufacturers.
Ege Akademik Bakis (Ege Academic Review), 2012
Social capital stems from the social relationships and yields highly critical benefits such as cr... more Social capital stems from the social relationships and yields highly critical benefits such as creativity, innovation and team productivity. However, the context and the structure of the social ties can potentially change the outcomes of social capital. This study aims to reveal the extent and the characteristics of social capital used in the radical innovation efforts. The strength of ties, type of trust and type of knowledge utilized in a selected radical innovation project were analyzed in this research. As an exploratory and descriptive study, case study method was adopted to investigate social capital as a relatively unexplored phenomenon, and to reflect the experiences of relevant individuals in regards to the social relationships embedded in the innovation efforts. The findings indicate that the organization has benefited from the existence and effective use of internal social capital, strong ties were developed and used among the members of the same department, strength of the ties got weaker as the team members, job descriptions and responsibilities started to vary and, finally, the case revealed that competence-based trust and tacit knowledge were found to be the essential parts of creative and innovative thinking.
Journal- South African Institute of Mining and Metallurgy
This paper deals with the selection of alternative accesses to a podiform chromite orebody in Tur... more This paper deals with the selection of alternative accesses to a podiform chromite orebody in Turkey. The most important alternatives studied in a related project have been stated as a new vertical shaft and a ramp system. The comparison of these alternatives have been carried out on the basis of total investment costs, ore transport unit cost and net present value (NPV) of overall project for various depth. The results show that up to the depth of 700 m, the total investment cost and NPV favours the ramp access while unit ore transport cost make the shaft access preferable.
Journal- South African Institute of Mining and Metallurgy
The aim of this paper is to demonstrate the implementation of multicriteria analysis in selection... more The aim of this paper is to demonstrate the implementation of multicriteria analysis in selection of the most suitable underground ore transport system for a chromite mine in Turkey. The related problem includes five possible ore transport systems and six criteria to evaluate them. The adopted evaluation and ranking method for this study is PROMETHEE. PROMETHEE I revealed a partial order of alternatives where incomparability exists. PROMETHEE II gave the absolute ordering of alternatives. The results have shown that the PROMETHEE method can be successfully used in solving mining engineering problems.
Journal of Management and Strategy, 2013
Innovation is still one of the most debated topics among the academics and business professionals... more Innovation is still one of the most debated topics among the academics and business professionals. The question of how organizations innovate captures attention from many disciplines and leads to extensive amount of research. Although there are many variables that affect an organization's innovative performance, organizational culture can be considered as a key issue as it is strongly associated with the values, attitudes, behaviors and organizational practices. As organizations have different cultural profiles and, in many cases, competing cultural values exist within the organization simultaneously, it is difficult to build one-dimensional linkages about the relations between organizational culture and innovativeness. This study aims to analyze the relations between innovativeness and four different organizational cultures including team, entrepreneurial, hierarchical and rational cultures. A sample of 371 surveys was collected from five leading companies operating in the chemicals industry in Eskisehir, Turkey.
Journal of Management Research, 2013
Radiation Physics and Chemistry, 2008
In this research, the effect of gamma irradiation on the inactivation of Escherichia coli O157: H... more In this research, the effect of gamma irradiation on the inactivation of Escherichia coli O157: H7 (ATCC 33150), Staphylococcus aureus (ATCC 2392) and Salmonella typhimurium (NRRL 4463) inoculated into Tekirdag meatballs was investigated. The meatball samples ...
Radiation Physics and Chemistry, 2012
We examine the combined effect of irradiation and storage low temperatures on shrimp. c Irradiati... more We examine the combined effect of irradiation and storage low temperatures on shrimp. c Irradiation and low temperature storage reduce the bacterial growth in shrimp. c Irradiation with frozen storage extend the shelf-life of shrimp meat to about 90 days. c The combined application stabilize the chemical characteristics of shrimp meat
Radiation Physics and Chemistry, 2008
... Tuncay Gumus Corresponding Author Contact Information , a , E-mail The Corresponding Author ,... more ... Tuncay Gumus Corresponding Author Contact Information , a , E-mail The Corresponding Author ,Umit Gecgel a , A. Sukru Demirci a and Muhammet Arici ... We are very grateful to Dr. Hasan Alkan and Gammapak Company for their kind supports during the irradiation of samples ...
Natural Resources Research, 2004
ABSTRACT In the mining industry, definitions of terms such as geologic resource, geologic reserve... more ABSTRACT In the mining industry, definitions of terms such as geologic resource, geologic reserve, mineral resource, mineral, mineral reserve, ore, ore reserve, mineable reserve, and industrial minerals always have been debated, and have caused much confusion. The process of arriving at these definitions requires complicated exploration, calculation, and evaluation. Based on such work, the definitions about the mineral property will be distinctly different. The aims of this paper is to discuss and compare these definitions, and then contrast the differences among them in the example of the Hasanelebi iron are deposit, which is an important source of iron ore in Turkey.
Korean Journal of Microbiology and Biotechnology, 2012
The aim of this study was to utilize rice bran, the main waste product of paddy processing, in xa... more The aim of this study was to utilize rice bran, the main waste product of paddy processing, in xanthan gum production by Xanthomonas campestris fermentation. Deffated rice bran was enzymatically hydrolyzed using cellulase, gluco-amylase, alpha-amylase and xylanase at various pHs and temperatures within 0-12 h. The highest sugar content reached at , pH 5.5 in 6 h with 41.66%. The enzymatic hydrolysate was used as the carbon source for xanthan gum production by X. campestris NRRL B-1459 and X. campestris pv. campestris. The highest productivities obtained were 21.87 and 17.10 g/L, respectively. Viscosity measurement for the obtained xanthan gums and commercial gum was carried out in gum solutions at various pHs and temperatures. The highest viscosity was reached with 1% gum solutions at and pH 5.5 for all gums with viscosity values of 470, 131 and 138 mPa sec, respectively. This work has provided relevant scientific information about the use of rice bran, an abundant agroindustrial residue, to produce xanthan gum.
Journal of Food Science and Technology, 2011
This study evaluated the effects of xanthan gum, guar gum, carrageenan and locust bean gum on phy... more This study evaluated the effects of xanthan gum, guar gum, carrageenan and locust bean gum on physical, chemical and sensory properties of meatballs. Meatball samples were produced with three different formulations including of 0.5, 1, and 1.5% each gum addition and gum added samples were compared with the control meatballs. Physical and chemical analyses were carried out on raw and cooked samples separately. Moisture contents of raw samples decreased by addition of gums. There were significant decreases (p<0.05) in moisture and fat contents of raw and cooked meatball samples formulated with gum when compared with control. Ash contents and texture values increased with gum addition to meatballs. Meatball redness decreased with more gum addition in raw and cooked meatball samples, which means that addition of gums resulted in a lighter-coloured product. According to sensory analysis results, locust bean gum added (1%) samples were much preferred by the panelists.
Food Science and Biotechnology, 2011
The influence of operational conditions (pH, stirrer speed, and temperature) used in the process ... more The influence of operational conditions (pH, stirrer speed, and temperature) used in the process of xanthan production by Xanthomonas axonopodis pv vesicatoria (XCVA3-1) isolated from pepper plant were evaluated through yield of xanthan and compared with control strain Xanthomonas campestris NRRL-B 1459. Different conditions used during the fermentation affected the xanthan production. In this study the best combination of yield was obtained, reaching 1.325 g/100 mL with the use of pH 7.0, 30 o C, and 250 rpm during fermentation. Increased yield of xanthan production can be obtained at high agitation values, with the maximum at 400 rpm. Higher yields of gum production can be obtained at 30 o C and the optimum pH was found 7.0. This results were similar for the X. campestris NRRL-B 1459.
Food Science and Biotechnology, 2010
In this study, the inhibitory properties of some essential oils including citrus (Citrus sinensis... more In this study, the inhibitory properties of some essential oils including citrus (Citrus sinensis L. Osbeck), laurel (Laurus nobilis L.), myrtle (Myrtus communis L.), oregano (Origanum vulgare L.), and savory (Satureja thymbra L.) were investigated against the heat resistant molds Aspergillus fumigatus and Paecilomyces variotii isolated from margarine in a previous study in order to assess the potential for using these essential oils as a natural food preservative. In this study, the essential oils of the plants were obtained by steam distillation using Clevenger apparatus and were tested for antifungal activities at 0.25, 0.50, and 1.00% concentrations. Inhibitory effects of the essential oils on the growth of the fungi followed the sequence: oregano=citrus>savory>laurel>myrtle. P. variotii was more resistant against the essential oils than A. fumigatus.
Food Science and Biotechnology, 2010
EJEAFCh, 2011
... REFERENCES 1. GK, Jayaprakasha, PS Negi, BS., Jena. In: NP Seeram, RN Schulman, and D. Heber.... more ... REFERENCES 1. GK, Jayaprakasha, PS Negi, BS., Jena. In: NP Seeram, RN Schulman, and D. Heber. Pomegranates: Ancient Roots to Modern Medicine p. 167183. ... J. Ethnopharmacol. 74, 113123 (2001). 8. D. Prashanth, MK Asha, A. Amit Fitoterapia. 72, 171173 (2001). ...
The Annals of Thoracic Surgery, 2005
Background. Antegrade selective cerebral perfusion as a method of cerebral protection during the ... more Background. Antegrade selective cerebral perfusion as a method of cerebral protection during the correction of aortic arch aneurysms and dissections is considered as a safe method for cerebral protection. There are still some questions remaining to be answered; such as whether cerebral perfusion through contralateral hemisphere is adequate. Method. Fifteen consecutive patients (mean age of 53 ؎ 3.3 years) underwent surgical reconstruction of aortic arch with antegrade selective cerebral perfusion through the right brachial artery. We monitored maximum, minimum and mean blood flow velocities of bilateral middle cerebral arteries using the transcranial Doppler technique at four different time periods: after induction of anesthesia, during cardiopulmonary bypass, during antegrade selective cerebral perfusion, and after termination of cardiopulmonary bypass. We compared the results of brachial cannulation group with aortic group. Results. Following induction, no significant differences were observed in the right and left middle cerebral artery blood flow velocity measurements in and between the groups. During cardiopulmonary bypass, V max and V mean decreased significantly in both groups. When two groups were compared there was a significant decrease in the left V max values of brachial group (p ؍ 0.048). In-group comparisons revealed that V max values were lower in left middle cerebral artery than right middle cerebral artery in brachial group (p ؍ 0.002). With the initiation of antegrade selective cerebral perfusion in brachial group, significant decrease occurred in V max and V mean when compared with cardiopulmonary bypass values. When left and right sides were compared, although V min values remained similar, V max and V mean values decreased significantly in the left side (p ؍ 0.001 and p ؍ 0.003, respectively). After cardiopulmonary bypass, in both groups, all values restored to initial values and indicated no difference between left and right middle cerebral artery in the groups as well as between the groups. No neurologic deficit was observed in any patient postoperatively. Conclusions. Antegrade selective cerebral perfusion through the right brachial artery, as a method of cerebral protection for aortic arch repair, seems to provide adequate perfusion for both right and left cerebral hemispheres.
Acta Alimentaria, 2013
In the present study, the antioxidant and antimicrobial activities of three tea (Camellia sinensi... more In the present study, the antioxidant and antimicrobial activities of three tea (Camellia sinensis) types (white tea-WT, green tea-GT, and black tea-BT) were compared and the relationships between total phenolic, tannin and fl avonoid contents were determined. Regardless of the assays used, the highest total phenolic content (313.3±1.41 μg GAE/mg extract), total fl avonoid (16.98±0.27 μg QE/mg extract) and total tannin content (266.79±2.59 μg TAE/ mg extract) were determined in green tea extract, which also demonstrated the highest antioxidant capacity. Black tea extract showed the lowest phenolic content and antioxidant capacity. The EC 50 value of DPPH scavenging activity was in the order of: ascorbic acid >GT>BHA>WT>BT>BHT. While the tea extracts exhibited antibacterial activity against Staphylococcus aureus, no inhibitory effects were observed against Escherichia coli and Salmonella enteritidis. All extracts exhibited antifungal activity against two afl atoxigenic moulds Aspergillus parasiticus NRRL 2999 and NRRL 465. The antibacterial activity of tea extracts decreased in the following order: GT>WT>BT DPPH scavenging activity strongly correlated with total phenolic content, reducing power, antimicrobial activity against S. aureus, A. parasiticus NRRL 2999, A. parasiticus NRRL 465 (P<0.05). These data suggest that green tea extract is more effective than white and black tea extracts as a potential source of natural antioxidants.
Gida the Journal of Food, 2016
Conjugated linoleic acid (CLA) is a common term of various positional and geometric isomers of li... more Conjugated linoleic acid (CLA) is a common term of various positional and geometric isomers of linoleicacid (LA) which contains two unsaturated double bonds in the fatty acid chains. Isomers are synthesizedas an intermediate product during the bacterial biohydrogenation of LA to stearic acid in the rumen ofruminants or from the conversion of trans vaccenic acid by the ∆9-desaturase enzyme in the mammaryglands and adipose tissues. CLA isomers are found in many foods, but mainly present in meat and dairyproducts obtained from ruminant animals. Although there are diverse positive effects of CLA isomerson health, some potential concerns that can be caused by these compounds have been stated in somestudies. CLA production is not specific to rumen bacteria; it was determined that some lactic acid andpropionic acid bacteria as well as microorganisms isolated from the milk products, human and animalintestines involved in the production. Therefore, use of these microorganisms in food industr...
Business and Economic Research, 2020
This study aims to understand whether the personal traits or the environmental conditions play a ... more This study aims to understand whether the personal traits or the environmental conditions play a more significant role in entrepreneurial intentions. Since intentions are strong predictors of the behaviors, it is important to understand whether the former or the latter factor has a stronger impact on entrepreneurial dispositions. In order to understand the complex relations between entrepreneurial intentions, personality traits, and perceived environmental conditions, total number of 229 economics and business administration students at Anadolu University, Faculty of Economics and Administrative Sciences were surveyed. Results of the statistical analysis have revealed that although the majority of the individual personal traits and contextual factors are perceived as strong predictors of entrepreneurial intentions, when considered as separate holistic structures; personal traits are better predictors for entrepreneurial intentions compared to contextual factors in Turkey.
Anadolu Üniversitesi Sosyal Bilimler Dergisi, 2019
Cynicism within the organizational context has been gaining ground in the last few decades due to... more Cynicism within the organizational context has been gaining ground in the last few decades due to massive changes in how business enterprises are run. Cynicism, from the organizational perspective, refers to a multi-faceted attitude characterized by negative feelings such as distrust, frustration and contempt toward the policies and practices of organization itself. In many cases, organizational cynicism reveals itself among employees as cynical attitudes toward managers. Such type of organizational cynicism is known as management cynicism. Although there are numerous organizational and individual causes lying behind management cynicism, this study focuses on how different organizational culture profiles affect management cynicism. In this study, four-quadrant organizational culture framework developed by Cameron and Freeman (1991) was adopted to illustrate if different cultural profiles and values attributed to them have significant impact on management cynicism. This paper examines the relations between different organizational culture profiles and management cynicism based on data collected from shop floor employees of four leading vendor companies for big-sized domestic appliance manufacturers.
Ege Akademik Bakis (Ege Academic Review), 2012
Social capital stems from the social relationships and yields highly critical benefits such as cr... more Social capital stems from the social relationships and yields highly critical benefits such as creativity, innovation and team productivity. However, the context and the structure of the social ties can potentially change the outcomes of social capital. This study aims to reveal the extent and the characteristics of social capital used in the radical innovation efforts. The strength of ties, type of trust and type of knowledge utilized in a selected radical innovation project were analyzed in this research. As an exploratory and descriptive study, case study method was adopted to investigate social capital as a relatively unexplored phenomenon, and to reflect the experiences of relevant individuals in regards to the social relationships embedded in the innovation efforts. The findings indicate that the organization has benefited from the existence and effective use of internal social capital, strong ties were developed and used among the members of the same department, strength of the ties got weaker as the team members, job descriptions and responsibilities started to vary and, finally, the case revealed that competence-based trust and tacit knowledge were found to be the essential parts of creative and innovative thinking.
Journal- South African Institute of Mining and Metallurgy
This paper deals with the selection of alternative accesses to a podiform chromite orebody in Tur... more This paper deals with the selection of alternative accesses to a podiform chromite orebody in Turkey. The most important alternatives studied in a related project have been stated as a new vertical shaft and a ramp system. The comparison of these alternatives have been carried out on the basis of total investment costs, ore transport unit cost and net present value (NPV) of overall project for various depth. The results show that up to the depth of 700 m, the total investment cost and NPV favours the ramp access while unit ore transport cost make the shaft access preferable.
Journal- South African Institute of Mining and Metallurgy
The aim of this paper is to demonstrate the implementation of multicriteria analysis in selection... more The aim of this paper is to demonstrate the implementation of multicriteria analysis in selection of the most suitable underground ore transport system for a chromite mine in Turkey. The related problem includes five possible ore transport systems and six criteria to evaluate them. The adopted evaluation and ranking method for this study is PROMETHEE. PROMETHEE I revealed a partial order of alternatives where incomparability exists. PROMETHEE II gave the absolute ordering of alternatives. The results have shown that the PROMETHEE method can be successfully used in solving mining engineering problems.
Journal of Management and Strategy, 2013
Innovation is still one of the most debated topics among the academics and business professionals... more Innovation is still one of the most debated topics among the academics and business professionals. The question of how organizations innovate captures attention from many disciplines and leads to extensive amount of research. Although there are many variables that affect an organization's innovative performance, organizational culture can be considered as a key issue as it is strongly associated with the values, attitudes, behaviors and organizational practices. As organizations have different cultural profiles and, in many cases, competing cultural values exist within the organization simultaneously, it is difficult to build one-dimensional linkages about the relations between organizational culture and innovativeness. This study aims to analyze the relations between innovativeness and four different organizational cultures including team, entrepreneurial, hierarchical and rational cultures. A sample of 371 surveys was collected from five leading companies operating in the chemicals industry in Eskisehir, Turkey.
Journal of Management Research, 2013
Radiation Physics and Chemistry, 2008
In this research, the effect of gamma irradiation on the inactivation of Escherichia coli O157: H... more In this research, the effect of gamma irradiation on the inactivation of Escherichia coli O157: H7 (ATCC 33150), Staphylococcus aureus (ATCC 2392) and Salmonella typhimurium (NRRL 4463) inoculated into Tekirdag meatballs was investigated. The meatball samples ...
Radiation Physics and Chemistry, 2012
We examine the combined effect of irradiation and storage low temperatures on shrimp. c Irradiati... more We examine the combined effect of irradiation and storage low temperatures on shrimp. c Irradiation and low temperature storage reduce the bacterial growth in shrimp. c Irradiation with frozen storage extend the shelf-life of shrimp meat to about 90 days. c The combined application stabilize the chemical characteristics of shrimp meat
Radiation Physics and Chemistry, 2008
... Tuncay Gumus Corresponding Author Contact Information , a , E-mail The Corresponding Author ,... more ... Tuncay Gumus Corresponding Author Contact Information , a , E-mail The Corresponding Author ,Umit Gecgel a , A. Sukru Demirci a and Muhammet Arici ... We are very grateful to Dr. Hasan Alkan and Gammapak Company for their kind supports during the irradiation of samples ...
Natural Resources Research, 2004
ABSTRACT In the mining industry, definitions of terms such as geologic resource, geologic reserve... more ABSTRACT In the mining industry, definitions of terms such as geologic resource, geologic reserve, mineral resource, mineral, mineral reserve, ore, ore reserve, mineable reserve, and industrial minerals always have been debated, and have caused much confusion. The process of arriving at these definitions requires complicated exploration, calculation, and evaluation. Based on such work, the definitions about the mineral property will be distinctly different. The aims of this paper is to discuss and compare these definitions, and then contrast the differences among them in the example of the Hasanelebi iron are deposit, which is an important source of iron ore in Turkey.
Korean Journal of Microbiology and Biotechnology, 2012
The aim of this study was to utilize rice bran, the main waste product of paddy processing, in xa... more The aim of this study was to utilize rice bran, the main waste product of paddy processing, in xanthan gum production by Xanthomonas campestris fermentation. Deffated rice bran was enzymatically hydrolyzed using cellulase, gluco-amylase, alpha-amylase and xylanase at various pHs and temperatures within 0-12 h. The highest sugar content reached at , pH 5.5 in 6 h with 41.66%. The enzymatic hydrolysate was used as the carbon source for xanthan gum production by X. campestris NRRL B-1459 and X. campestris pv. campestris. The highest productivities obtained were 21.87 and 17.10 g/L, respectively. Viscosity measurement for the obtained xanthan gums and commercial gum was carried out in gum solutions at various pHs and temperatures. The highest viscosity was reached with 1% gum solutions at and pH 5.5 for all gums with viscosity values of 470, 131 and 138 mPa sec, respectively. This work has provided relevant scientific information about the use of rice bran, an abundant agroindustrial residue, to produce xanthan gum.
Journal of Food Science and Technology, 2011
This study evaluated the effects of xanthan gum, guar gum, carrageenan and locust bean gum on phy... more This study evaluated the effects of xanthan gum, guar gum, carrageenan and locust bean gum on physical, chemical and sensory properties of meatballs. Meatball samples were produced with three different formulations including of 0.5, 1, and 1.5% each gum addition and gum added samples were compared with the control meatballs. Physical and chemical analyses were carried out on raw and cooked samples separately. Moisture contents of raw samples decreased by addition of gums. There were significant decreases (p<0.05) in moisture and fat contents of raw and cooked meatball samples formulated with gum when compared with control. Ash contents and texture values increased with gum addition to meatballs. Meatball redness decreased with more gum addition in raw and cooked meatball samples, which means that addition of gums resulted in a lighter-coloured product. According to sensory analysis results, locust bean gum added (1%) samples were much preferred by the panelists.
Food Science and Biotechnology, 2011
The influence of operational conditions (pH, stirrer speed, and temperature) used in the process ... more The influence of operational conditions (pH, stirrer speed, and temperature) used in the process of xanthan production by Xanthomonas axonopodis pv vesicatoria (XCVA3-1) isolated from pepper plant were evaluated through yield of xanthan and compared with control strain Xanthomonas campestris NRRL-B 1459. Different conditions used during the fermentation affected the xanthan production. In this study the best combination of yield was obtained, reaching 1.325 g/100 mL with the use of pH 7.0, 30 o C, and 250 rpm during fermentation. Increased yield of xanthan production can be obtained at high agitation values, with the maximum at 400 rpm. Higher yields of gum production can be obtained at 30 o C and the optimum pH was found 7.0. This results were similar for the X. campestris NRRL-B 1459.
Food Science and Biotechnology, 2010
In this study, the inhibitory properties of some essential oils including citrus (Citrus sinensis... more In this study, the inhibitory properties of some essential oils including citrus (Citrus sinensis L. Osbeck), laurel (Laurus nobilis L.), myrtle (Myrtus communis L.), oregano (Origanum vulgare L.), and savory (Satureja thymbra L.) were investigated against the heat resistant molds Aspergillus fumigatus and Paecilomyces variotii isolated from margarine in a previous study in order to assess the potential for using these essential oils as a natural food preservative. In this study, the essential oils of the plants were obtained by steam distillation using Clevenger apparatus and were tested for antifungal activities at 0.25, 0.50, and 1.00% concentrations. Inhibitory effects of the essential oils on the growth of the fungi followed the sequence: oregano=citrus>savory>laurel>myrtle. P. variotii was more resistant against the essential oils than A. fumigatus.
Food Science and Biotechnology, 2010
EJEAFCh, 2011
... REFERENCES 1. GK, Jayaprakasha, PS Negi, BS., Jena. In: NP Seeram, RN Schulman, and D. Heber.... more ... REFERENCES 1. GK, Jayaprakasha, PS Negi, BS., Jena. In: NP Seeram, RN Schulman, and D. Heber. Pomegranates: Ancient Roots to Modern Medicine p. 167183. ... J. Ethnopharmacol. 74, 113123 (2001). 8. D. Prashanth, MK Asha, A. Amit Fitoterapia. 72, 171173 (2001). ...
The Annals of Thoracic Surgery, 2005
Background. Antegrade selective cerebral perfusion as a method of cerebral protection during the ... more Background. Antegrade selective cerebral perfusion as a method of cerebral protection during the correction of aortic arch aneurysms and dissections is considered as a safe method for cerebral protection. There are still some questions remaining to be answered; such as whether cerebral perfusion through contralateral hemisphere is adequate. Method. Fifteen consecutive patients (mean age of 53 ؎ 3.3 years) underwent surgical reconstruction of aortic arch with antegrade selective cerebral perfusion through the right brachial artery. We monitored maximum, minimum and mean blood flow velocities of bilateral middle cerebral arteries using the transcranial Doppler technique at four different time periods: after induction of anesthesia, during cardiopulmonary bypass, during antegrade selective cerebral perfusion, and after termination of cardiopulmonary bypass. We compared the results of brachial cannulation group with aortic group. Results. Following induction, no significant differences were observed in the right and left middle cerebral artery blood flow velocity measurements in and between the groups. During cardiopulmonary bypass, V max and V mean decreased significantly in both groups. When two groups were compared there was a significant decrease in the left V max values of brachial group (p ؍ 0.048). In-group comparisons revealed that V max values were lower in left middle cerebral artery than right middle cerebral artery in brachial group (p ؍ 0.002). With the initiation of antegrade selective cerebral perfusion in brachial group, significant decrease occurred in V max and V mean when compared with cardiopulmonary bypass values. When left and right sides were compared, although V min values remained similar, V max and V mean values decreased significantly in the left side (p ؍ 0.001 and p ؍ 0.003, respectively). After cardiopulmonary bypass, in both groups, all values restored to initial values and indicated no difference between left and right middle cerebral artery in the groups as well as between the groups. No neurologic deficit was observed in any patient postoperatively. Conclusions. Antegrade selective cerebral perfusion through the right brachial artery, as a method of cerebral protection for aortic arch repair, seems to provide adequate perfusion for both right and left cerebral hemispheres.
Acta Alimentaria, 2013
In the present study, the antioxidant and antimicrobial activities of three tea (Camellia sinensi... more In the present study, the antioxidant and antimicrobial activities of three tea (Camellia sinensis) types (white tea-WT, green tea-GT, and black tea-BT) were compared and the relationships between total phenolic, tannin and fl avonoid contents were determined. Regardless of the assays used, the highest total phenolic content (313.3±1.41 μg GAE/mg extract), total fl avonoid (16.98±0.27 μg QE/mg extract) and total tannin content (266.79±2.59 μg TAE/ mg extract) were determined in green tea extract, which also demonstrated the highest antioxidant capacity. Black tea extract showed the lowest phenolic content and antioxidant capacity. The EC 50 value of DPPH scavenging activity was in the order of: ascorbic acid >GT>BHA>WT>BT>BHT. While the tea extracts exhibited antibacterial activity against Staphylococcus aureus, no inhibitory effects were observed against Escherichia coli and Salmonella enteritidis. All extracts exhibited antifungal activity against two afl atoxigenic moulds Aspergillus parasiticus NRRL 2999 and NRRL 465. The antibacterial activity of tea extracts decreased in the following order: GT>WT>BT DPPH scavenging activity strongly correlated with total phenolic content, reducing power, antimicrobial activity against S. aureus, A. parasiticus NRRL 2999, A. parasiticus NRRL 465 (P<0.05). These data suggest that green tea extract is more effective than white and black tea extracts as a potential source of natural antioxidants.