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Hasene Keskin Derya Koçak Yanık Hatice Neval Mucuk Fahrettin Göğüş Sibel Fadıloğlu 《Journal of food science》2016,81(4):C841-C848
2‐Monoacylglycerols (2‐MAG) with a high content of oleic acid at sn‐2 position was synthesized by enzymatic ethanolysis of refined olive pomace oil, which is a byproduct of olive oil processing. Six lipases from different microbial sources were used in the synthesis of 2‐MAG. Immobilized lipase from Candida antarctica gave the highest product yield among the selected lipases. Response surface methodology was applied to optimize reaction conditions; time (4 to 10 h), temperature (45 to 60 °C), enzyme load (10 to 18 wt%), and ethanol:oil molar ratio (30:1 to 60:1). The predicted highest 2‐MAG yield (84.83%) was obtained at 45 °C using 10 (wt%) enzyme load and 50:1 ethanol:oil molar ratio for 5 h reaction time. Experiments to confirm the predicted results at optimum conditions presented a 2‐MAG yield of 82.54%. The purification yield (g 2‐MAG extracted/100 g of total product) was 80.10 and 69.00 for solvent extraction and low‐temperature crystallization, respectively. The purity of the synthesized 2‐MAG was found to be higher than 96%. 相似文献
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pH and heat‐dependent behaviour of glucose oxidase down to single molecule level by combined fluorescence spectroscopy and molecular modelling
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İkbal Sarıkaya Halide Akbaş 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(23):3514-3520
Frying of sunflower, corn, and canola oils was carried out for seven running days at 175°C in this study. Fatty acid composition, free fatty acid, viscosity, iodine value, peroxide value, density, pH, saponification value, refractive index, average molecular weight, color, and the higher heating value of these oils have been analyzed. While the contents of free fatty acid, viscosity, saponification value, peroxide value, and colors (red and yellow) increase with the frying times, the contents of average molecular weight, iodine value, pH, and the higher heating value decreased for all oils in this work. However, reduction in the higher heating value is relatively low. This work indicated that recycling as a fuel of these oils can make a major economic contribution. 相似文献
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Ömer Güler Mustafa Boyrazlı Öyküm Başgöz Bayram Bostancı 《Canadian Metallurgical Quarterly》2017,56(3):349-359
Tea wastes are rich in carbon, nitrogen and potassium but poor in phosphorus, which signifies that they can also be used to reduce metal oxides after they are carbonised. The tea wastes were carbonised at the first stage. The sample, which was put into a ladle with screw cap, was carbonised in a muffle furnace at 400, 500, 600, 700 and 800°C for 30, 60, 90, 120, 240, 360, 720 and 1440?min. It was determined that carbon and sulphur contents of the sample carbonised at 800°C for 1440?min were 94.68 and 0.05%, respectively. Calorific value of the same sample was 8652?cal?g?1. It was found that with increasing temperature, carbon ratio of the carbonised samples increased and their sulphur ratio decreased from 0.39 to 0.05%. The carbonised structure was subjected to the milling process as the second stage. In the milling process, particle size of the carbon-rich sample was brought into nano size and the structure acquired the energy, required for the third stage. The amorphous carbon structure obtained after the milling process was subjected to annealing process at 1400°C as the third stage. As a result of these processes, carbon nanotubes (CNTs), carbon nano-onion structures and amorphous carbon structures were determined in the structure. 相似文献