10 research outputs found
desorption GC x GC-TOF/MS
Volatile compounds were isolated from Cheddar cheese using direct thermal desorption (DTD) and analysed using comprehensive 2-D GC (GC x GC) coupled with TOF MS (TOF/MS). In total 12 aldehydes, 13 acids, 13 ketones, 5 alcohols, 3 hydrocarbons and 9 miscellaneous compounds were identified at desorption temperatures of 100, 150, 200 and 250 degrees C using mature Cheddar cheese. A temperature of 150 degrees C was found to be optimum for the DTD of volatiles from mature Cheddar cheese. The major components were acetic acid, butanoic acid, 3-hydroxy-2-butanone and 2,3-butanediol. A DTD temperature of 150 degrees C was used to observe the effect of maturation (mild, medium or mature) on the volatiles of Cheddar cheese. The major components of the volatiles of mild, medium and mature Cheddar cheese were almost the same. However, their percentage compositions were found to change with the stage of maturity. DTD is simple, fast and requires only a small amount of sample (approximately 10 mg) and works well with comprehensive GC x GC-TOF/MS. Comprehensive GC also separated a number of components which remained overlapped on the single column, such as octane and hexanal
GCxGC-TOF/MS Chromatographic Analysis, Antioxidant Capacity and Phenolic Content of Rosa Canina L. at Different Maturities
The relationship between food and health has become increasingly significant as consumers now demand healthy, tasty and natural foods which perform a useful function in the body. In Turkey, rose hip (Rosa canina L.) is in popular use in foodstuffs such as marmalade, pestil (a traditional Turkish sweet) and syrup or in traditional medicine, mainly as herbal tea. The composition, total antioxidant capacity (TAC) and total phenolic content (TPC) of volatiles of rose hip samples were compared in relation to their stage of maturity and collection location. Rose hip fruit and seed were analyzed using a direct thermal desorption technique coupled with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOF/MS). The major components found in the volatile fraction released on extraction were free fatty acids. The various stages of maturity of rose hips (green, light yellow, yellow, orange and red coloured) and the place of collection (Istanbul, Mersin, York) resulted in some changes in volatile compound speciation, in TAC and TPC levels. Various extraction methods were compared; methanol extraction, traditional hot water infusion and boiling in water. Boiling in water for ten minutes was the method which demonstrated the highest extraction efficiency. TAC and TPC were determined using different electron transfer-based assays; the Cerium (IV) ions reducing antioxidant capacity, Cupric Reducing Antioxidant Capacity and Folin-Ciocalteu methods. The highest TAC and TPC were found in the red coloured (fully ripe) rose hip fruit, suggesting that colour is a suitable indicator for optimal harvesting time. (C) 2016 ACG Publications. All rights reserved
Effect of some heating parameters on volume expansion of borax
About 70% of the world's total boron reserves are located in Turkey. Boron minerals are typically concentrated by attrition scrubbing followed by screening and classification to remove clay minerals and other impurities. These wet concentration methods, however, result in a considerable amount of accumulated tailings in large tailings dams. The tailings are approximately 28% solids and contain 14% B(2)O(3). Problems caused by these tailings can be minimized by employing dry beneficiation techniques involving heat treatment. This method has been successfully tested on laboratory, and pilot scales. During heat treatment, borax undergoes expansion in volume. The amount of expansion is dependent on the particle size, temperature and duration of heat treatment. Because the optimum temperature and the duration of the heat treatment are not well defined, the boron ore acts as a calcined clay mineral and is discarded along with the gangue. It is important to predict such parameters using mathematical formulations. Thus, a mathematical model is used to predict the required temperature and duration period prior to heat treatment. In the experimental study presented here, a series of systematic thermal tests was carried out in a muffle furnace. Two variables, temperature and time, were studied in a response surface design. A quadratic regression model was chosen and regression coefficients were calculated. Using a regression equation, the volume expansion of the particles in various circumstances can be predicted. The mathematical test results are then correlated with the experimental results to relate the optimum expansion of borax with heating time and temperature and with borax grades and recoveries
Analysis of volatile components from Ziziphora taurica subsp. taurica by steam distillation, superheated-water extraction, and direct thermal desorption with GC×GC–TOFMS
Analysis of volatile components from Tanacetum cadmeum by hydrodistillation and direct thermal desorption methods using GC×GC-TOF/MS
National survey study on the approaches of pediatricians, family physicians, medical oncologists and gynecologists to the HPV vaccine
Objective: In this study, we aimed to emphasize the critical role of physician recommendations in increasing the HPV vaccination rates, and to create awareness in this regard, by revealing the approach of oncologists, gynecologists, pediatricians, and family physicians, who are the primary interlocutors in the matter of HPV vaccination. Procedures: The study was prepared by conducting a questionnaire in a face-to-face manner, with the participation—on the basis of volunteerism—of 425 physicians including oncologists, gynecologists, pediatricians and family physicians. The interviews were conducted at 4 separate national oncology, pediatrics, gynecology and family medicine congresses. With the questions, the participants' attitudes towards HPV vaccination as well as the power, timing, consistency and scope of their recommendations were questioned. Findings: In the study; 33% of the respondents stated that the vaccination was not important, and the ones who considered it to be unnecessary (31%) pointed out its non-cost effectiveness to justify their opinion. Only 51% of the respondents stated that the vaccine should be administered to both girls and boys. The rate of the respondents who stated that it should be administered to those with a risk factor was only 19%. 21% of the respondents stated that they promoted the vaccination in their routine practice. In addition, it was observed that the respondents, who answered correctly the question intended for questioning the their knowledge about HPV’s share in all types of cancer, considered the vaccine to be more important and recommended it more in their routine practices. Results: The results of the analyses reveal that the low HPV vaccination rates are caused substantially by the attitudes of physicians regarding the vaccination; that they do not adequately play a role in its promotion; and that it should be the basic strategy to increase the physicians’ level of knowledge about the vaccine, for increasing the rate of vaccination. Efficacy: This is the first study in the literature, which involves the evaluation of the attitudes of physicians—who are the primary interlocutors in the matter of HPV vaccination—from 4 branches towards HPV vaccination. The study is also one of the first studies involving a sophisticated evaluation of the attitudes of physicians towards HPV vaccination. In terms of its results, the study has a nature that gives information and inspiration to people, institutions, and organizations both in Turkey and other countries, who/which have an aim to increase the rates of HPV vaccination. Keywords: Human papilloma virus, HPV vaccine, Cancer, Preventive medicin
A biorefinery strategy for spent industrial ginger waste
An integrated biorefinery approach using spent industrial ginger waste for resource recovery is reported. Valuable products including ginger oil, starch, microfibrillated cellulose (MFC), bio-oil and hydrochar were obtained. Approximately 4 % ginger oil, with a profile similar to commercial ginger oil, can be recovered via Soxhlet or Supercritical CO2 + 10 %EtOH extraction. The oil-free ginger residues were processed using two microwave techniques: starch, MFC and sugar-rich hydrolysates were firstly gained through hydrothermal microwave processing (120–200 °C in water alone), whilst chemical-rich bio-oils and energy-dense hydrochar (20–24.5 MJ kg−1) were obtained via conventional microwave pyrolysis (220–280 °C). The ginger MFC exhibited increased propensity to form microfibrillated cellulose (as evidenced by Transmission Electron Microscopy) with increasing temperature. Nanocrystalline cellulose was produced at the highest processing temperature (200 °C). These changes are commensurate with the leaching and decomposition of the amorphous regions within cellulose. The molecules and materials isolated have further downstream applications and, thus, compared to current low value resolution methods (dumping, burning or animal feed), spent industrial ginger waste is a significant resource for consideration within a biorefinery concept