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71.
Effect of Relative Humidity on the Oxidative Stability of Microencapsulated Sea Buckthorn Seed Oil 总被引:1,自引:0,他引:1
Riitta Partman Piia Hakala Olli Sjövall Heikki Kallio Pirkko Forssell 《Journal of food science》2005,70(1):E37-E43
ABSTRACT: The effect of relative humidity (RH) (20 °C: RH 11%, 54%) on oxidative stability microencapsulated sea buckthorn seed oil was studied using bulk oil as a reference. Microcapsules were prepared by spray-drying using maltodextrin-gum arabic (MD/GA) and corn starch sodium octenyl succinate derivate (HiCap) as the wall materials. The influence of the physical state of the wall material was also evaluated. Under dry conditions, the microencapsulated oils were most stable, but the oxidation of the bulk oil was accelerated. At 20 °C and at RH 11%, the peroxide value of the bulk oil exceeded 20 meq/kg within 1 wk. Microencapsulation prolonged the shelf-life of the oil from 1 wk to 2 mo at 20 °C, when the encapsulating matrix was in glassy state. In conditions in which the HiCap matrix was in a rubbery state (RH 54%, 20 °C), the oxidation proceeded very quickly, reaching a peroxide value of 20 meq/kg just after 1 wk. Caking and collapse of the microcapsule powder were observed in the rubbery state. At accelerated conditions (50 °C: RH 11%, 30%, 45%), the oxidation was noticeably fast, not only in the bulk oil but also in the MD/GA matrix, even in the glassy state. The behavior in the HiCap matrix was more complex as the amount of peroxides started to decrease in time. This was assigned to the structural collapse in HiCap microcapsules. The behavior of the microencapsulated oils under accelerated conditions did not correlate with their behavior at 20 °C. 相似文献
72.
Alterations in chylomicron and VLDL TAG and the magnitude of postprandial lipemia were studied in healthy volunteers after
two meals of equal FA composition but different TAG-FA positional distribution. Molecular level information of individual
lipoprotein TAG regioisomers was obtained with a tandem MS method. The incremental area under the response curve of VLDL TAG
was large (P=0.021) after modified lard than after lard. In plasma TAG, the difference did not quite reach statistical significance (P=0.086). In general, there were less TAG with palmitic acid in the sn-2 position and more TAG with oleic acid in the sn-2 position in chylomicrons than in fat ingested. From 1.5 to 8 h postprandially, the proportion of individual chylomicron
TAG was constant or influenced by TAG M.W. VLDL TAG regioisomerism was similar regardless of the positional distribution of
fat ingested. Significant alterations were seen in VLDL TAG FA, in M.W. fractions, and in individual regioisomers with respect
to time. The TAG sn-14∶0-18∶1-18∶1+sn-18∶1-18∶1-14∶0, sn-16∶0-16∶1-18∶1+sn-18∶1-16∶1-16∶0, and sn-16∶1-18∶1-18∶1+sn-18∶1-18∶1-16∶1 decreased (P<0.05); and sn-16∶0-16∶0-18∶2+sn-18∶2-16∶0-16∶0, sn-16∶0-16∶0-18∶1+sn-18∶1-16∶0-16∶0, sn-16∶0-18∶1-16∶0, and sn-16∶0-18∶1-18∶2+sn-18∶2-18∶1-16∶0 increased (P<0.05) after both meals. In conclusion, positional distribution of TAG FA was found to affect postprandial lipid metabolism
in healthy normolipidemic subjects. 相似文献
73.
Abstract. Information system (IS) innovation can be defined as a novel organizational application of digital computer and information communication technologies (ICT). This paper discusses how modalities of applying ICT technologies in their form and scope exhibit radical breaks, which are introduced herein as ‘disruptive IS innovations’. This notion of disruptive IS innovation is developed by drawing upon and extending Swanson's (1994) theory of IS innovation as well as the concept of radical innovation. Disruptive innovations strongly influence the future trajectory of the adoption and use of ICT in organizational contexts and make the trajectory deviate from its expected course. In doing so, these disruptive innovations distinctly define what an IS is and how it is deployed in order to address current and future organizational and managerial prerogatives. Such changes are triggered breakthroughs in the capability of ICT that lead to the revision and expansion of associated cognitive models (frames) of computing. Disruptive IS innovations are those that lead to changes in the application of ICT that are both pervasive and radical. The pervasive nature implies that innovative activity spans all innovation subsets of the quad‐core model of IS innovation introduced herein. Innovation types include: IS use and development processes; application architecture and capability; and base technologies. Radical in nature, disruptive is innovations depart in significant ways from existing alternatives and lead to deviation from expected use and diffusion trajectory. This paper demonstrates the importance of a concept of disruptive IS innovation by investigating how changes triggered by internet computing (Lyytinen et al., 1998) meet the conditions of a disruptive IS innovation defined herein. The analysis also affirms both the pervasive and radical nature of internet computing and explains how internet computing has fundamentally transformed the application portfolio, development practices and IS services over time. The analysis demonstrates that, with the concept of disruptive IS innovation, we can fruitfully analyse ‘long’ waves of ICT evolution – an issue that has largely been overlooked in the IS community. On a theoretical plane, the paper advocates the view that we need to look beyond linear, unidirectional, and atomistic concepts of the diffusion of IS innovations where innovative activity takes places in a linear fashion by oscillating between small technological innovations and small organizational innovations. In contrast, IS innovation can exhibit fundamental discontinuity; we need to theoretically grasp such disruptive moments. The recent influx of innovation, spurred by internet‐based technology, offers one such moment. 相似文献
74.
Scientometrics - In this study we investigated whether open access could assist the broader dissemination of scientific research in Climate Action (Sustainable Development Goal 13) via news... 相似文献
75.
Nurul Anwar Tommi Sappinen Kalle Jalava Juhani Orkas 《Advanced Powder Technology》2021,32(6):1902-1910
A good sand mold is an indispensable prerequisite to obtaining a good metal casting. Although sand casting is one of the oldest metal forming technique known to humans, it still has a lot to discover. In a bid to meet the ever-growing demand for quality, economics and increasing environmental restrictions, research is still ongoing to optimize for example the process of making the sand mold. This paper presents a comparative study of six different foundry sands for flowability using simple inexpensive apparatus and some quality parameters achieved by these sands when used with three different types of binder, two organic and one inorganic. The study aims to facilitate the choice of mold materials with a more extensive outlook into their characteristics through a serious of sand and mold tests. A good comparison of already existing materials provides a good reference point when novel materials are investigated. All the sands exhibited ‘good’ flow property according to the simple flowability tests done. However, not the same consensus for flowability rank is reached by all the flow tests. The mold quality tests reveal the strength, loss on ignition and permeability values achieved with each of the binder and sand combination which can also be used in mold material selection. 相似文献
76.
77.
Kalle Sigfridsson Thomas Andersson Veronica Berntsson Yudong Wang 《Drug development and industrial pharmacy》2015,41(5):866-873
AZD9343 is a water-soluble gamma amino butyric acid (GABAB) agonist intended for symptomatic relief in gastroesophageal reflux disease (GERD) patients. The compound has good chemical stability in aqueous solutions, as well as in the solid state. Only one crystal modification has been observed to date. This polymorph is slightly hygroscopic (1.5% water uptake at 80% relative humidity (RH)), which is an improvement compared to the structurally similar agonist lesogaberan (AZD3355) which liquefies at 65% RH. Since the substance is very polar and lacks a UV chromophore, conventional separation and detection techniques cannot be used to characterize the substance and its impurities. The analytical techniques are described, focusing on the capillary electrophoresis method with indirect UV detection for assay and purity, the liquid chromatographic method for enantiomeric separation with derivatization with UV chromophore and three complementary nuclear magnetic resonance (NMR) approaches (31P-NMR, 13C-NMR and 1H-NMR) for impurities. For oral solutions, it was important to select the right concentration of phosphate buffer for the specific drug concentration and routinely use small additions of EDTA. I.V. solutions containing physiological saline as tonicity modifier could not be stored frozen at ?20?°C. Properties of AZD9343 will be discussed in light of experiences from the structurally similar lesogaberan and (2R)-(3-amino-2-fluoropropyl)sulphinic acid (AFPSiA). 相似文献
78.
79.
In this paper we investigate the geometry and algebra of multiple one-dimensional projections of a two-dimensional environment. This is relevant for one-dimensional cameras, e.g. as used in certain autonomous guided vehicles. It is also relevant for understanding the projection of lines in ordinary vision. A third application is on ordinary vision of vehicles undergoing so called planar motion. The structure and motion problem for such cameras is studied and the two possible minimal cases is solved. The technique of solving these questions reveal interesting ambiguities. It is shown that for each solution with three images there is an ambiguous solution. It is also shown that for each solution for four points there is an ambiguous solution. The connection between these two different types of ambiguities is also given. Although the paper deals with calibrated cameras, it is shown that similar results exist for uncalibrated cameras. 相似文献
80.
Nanocomposite films and coatings with improved properties were produced from ultrasonic dispersed chitosan and hydrophilic bentonite nanoclay. Bio‐hybrid coatings were applied onto argon–plasma‐activated LDPE coated paper. The intercalation of chitosan in the silicate layers was confirmed by the decrease of diffraction angles as the chitosan/nanoclay ratio increased. Nanocomposite films and multilayer coatings had improved barrier properties against oxygen, water vapor, grease, and UV‐light transmission. Oxygen transmission was significantly reduced under all humidity conditions. In dry conditions, over 99% reduction and at 80% relative humidity almost 75% reduction in oxygen transmission rates was obtained. Hydrophilic chitosan was lacking the capability of preventing water vapor transmission, thus total barrier effect of nanoclay containing films was not more than 15% as compared with pure chitosan. Because to very thin coatings (≤1 μm), nanoclay containing chitosan did not have antimicrobial activity against test strains. All coating raw materials were “generally recognized as safe” (GRAS) and the calculated total migration was in all cases ≤6 mg/dm2, thus the coatings met the requirements set by the packaging legislation. Processing of the developed bio‐hybrid nanocomposite coated materials was safe as the amounts of released particles under rubbing conditions were comparable with the particle concentrations in a normal office environment. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献