다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

The application of the spray drying technique in the food industry for the production of a broad range of ingredients has become highly desirable compared to other drying techniques. Recently, the spray drying technique has been applied extensively for the production of functional foods, pharmaceuticals and nutraceuticals. Encapsulation using spray drying is highly preferred due to economic advantages compared to other encapsulation methods. Encapsulation of oils using the spray drying technique is carried out in order to enhance the handling properties of the products and to improve oxidation stability by protecting the bioactive compounds. Encapsulation of oils involves several parameters—including inlet and outlet temperatures, total solids, and the type of wall materials—that significantly affect the quality of final product. Therefore, this review highlights the application and optimization of the spray drying process for the encapsulation of oils used as food ingredients.

Spray Drying for the Encapsulation of Oils-A Review

Lipase-catalyzed transesterification of triglycerides and alcohols to obtain biodiesel is an environmentally friendly and sustainable route for fuels production since, besides proceeding in mild reaction conditions, it allows for the use of low-cost feedstocks that contain water and free fatty acids, for example non-edible oils and waste oils. This review article reports recent advances in the field and focus in particular on a major issue in the enzymatic process, the inactivation of most lipases caused by methanol, the preferred acyl acceptor used for alcoholysis. The recent results about immobilization of enzymes on nano-materials and the use of whole-cell biocatalysts, as well as the use of cell-surface display technologies and metabolic engineering strategies for microbial production of biodiesel are described. It is discussed also insight into the effects of methanol on lipases obtained by modeling approaches and report on studies aimed at mining novel alcohol stable enzymes or at improving robustness in existing ones by protein engineering.

Enzymatic Production of Biodiesel: Strategies to Overcome Methanol Inactivation.

Insights into the relations between the molecular structures and digestion properties of retrograded starch after ultrasonic treatment

Supercritical carbon dioxide (SC-CO2) has been used as green solvent in the lipase-catalyzed ethanolysis of fish oil by Lipozyme RM IM at mild, non-oxidative conditions and with no solvent residues. The effect of experimental conditions, initial substrate ethanol/oil molar ratio (2–38), pressure (7.5–30 MPa), and temperature (323.15–353.15 K) on equilibrium conversion, reaction rate and oxidative status of the products has been studied. No ethanol inhibition has been observed at high concentrations of ethanol, when putting in contact first the fish oil with the enzyme avoiding direct contact between the biocatalyst and ethanol. Operating pressure affected positively the reaction performance in the range investigated. Visual observation of the phase behaviour of the initial reaction mixture showed an “expanded liquid phase” that helped enhancing reaction rate, and a gas phase. Raising temperature accelerated the reaction up to a limit (343.15 K), observing higher enzyme thermal stability than in other reaction media (313.15 K). However, lipid oxidation increases with temperature. Up to 86 ± 1% FAEE yield has been found at MR = 6:1, 30 MPa and 323.15 K. Kinetic data have been correlated by using a mathematical model based on the elementary reactions of the 3-step transesterification. Kinetic rate constants, apparent activation volumes and energies are reported for the first time for a lipase-catalyzed ethanolysis reaction in SC-CO2.

Supercritical carbon dioxide as solvent in the lipase-catalyzed ethanolysis of fish oil: Kinetic study

Omega–3 encapsulation by PGSS-drying and conventional drying methods. Particle characterization and oxidative stability

Tyrosinase from mushroom was used as a model polyphenol oxidase (PPO) enzyme to perform a systematic inactivation study using High Pressure Carbon Dioxide (HPCD). The ratio CO2/volume of enzyme (g/mL) loaded in the reactor was found to be critical. Above a critical ratio, pressure, temperature and time did not control the inactivation performance. Exposure time (2–15 min), temperature (25–45 °C) and pressure (5–20 MPa) allowed to show a characteristic inactivation pattern for PPO: a sudden decrease in activity (at least 75% of the total activity loss was observed within the first 2 min) was followed by a slowed decay. The experimental data were fitted into a two fraction kinetic model and the main kinetic parameters (ZP, ZT activation volume and activation energy) were calculated. The fluorescence spectroscopy analysis of the samples treated with HPCD revealed significant changes in the tertiary structure of the enzyme.

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Esther de Paz

Papers

Supercritical carbon dioxide as solvent in the lipase-catalyzed ethanolysis of fish oil: Kinetic study

Omega–3 encapsulation by PGSS-drying and conventional drying methods. Particle characterization and oxidative stability

Studies of polyphenol oxidase inactivation by means of high pressure carbon dioxide (HPCD)