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Rheological measurement was employed to study the mutarotation of D-fructose in anhydrous state. By monitoring the evolution of shear viscosity with time, rate constants for mutarotation were estimated, and two different stages of this reaction were identified. One of the mutarotation stages is rapid and has a low activation energy, whereas the other is much slower and has a much higher activation energy. Possible conversions corresponding to these two phases are discussed. This work demonstrates that, in addition to the routine techniques such polarimetry and gas-liquid chromatography, rheological measurement can be used as an alternative method to continuously monitor the mutarotation of sugars.
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http://dx.doi.org/10.1021/jp310471b | DOI Listing |
Eur J Pharm Biopharm
December 2024
Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, Universityof Helsinki, 00790 Helsinki, Finland; Timegate Instruments Oy, 90590 Oulu, Finland; School of Pharmacy, Universityof Eastern Finland, 70210 Kuopio, Finland; Circuits and Systems Research Unit, University
Freeze-drying enables delicate, heat-sensitive biomaterials to be stored in a dry form even at room temperature. However, exposure to physicochemical stress induced by freeze-drying presents challenges for maintaining material characteristics and functionality upon reconstitution, for which reason excipients are required. Although wide variety of different excipients are available for pharmaceutical applications, their protective role in the freeze-drying is not yet fully understood.
View Article and Find Full Text PDFCarbohydr Res
November 2024
Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, Sichuan, 610064, PR China. Electronic address:
Although the xylose mutarotation and transformation have been investigated largely separately, their relationship has been rarely systematically elaborated. The effect of several factors such as xylose concentration, temperature, and salt concentration, affecting the mutarotation of xylose are discussed. Nine alkali halides (LiCl, NaCl, KCl, LiBr, NaBr, KBr, LiI, NaI, and KI) are used to test salt effects.
View Article and Find Full Text PDFAppl Spectrosc
September 2024
Research Division of Environmental Analytics, Process Analytics and Sensors, Institute of Chemical Technologies and Analytics, Technische Universität Wien, Vienna, Austria.
Ongoing technological advancements in the field of mid-infrared (MIR) spectroscopy continuously yield novel sensing modalities, offering capabilities beyond traditional techniques like Fourier transform infrared spectroscopy (FT-IR). One such advancement is MIR dispersion spectroscopy, utilizing a tunable quantum cascade laser and Mach-Zehnder interferometer for liquid-phase analysis. Our study assesses the performance of a custom MIR dispersion spectrometer at its current development stage, benchmarks its performance against FT-IR, and validates its potential for time-resolved chemical reaction monitoring.
View Article and Find Full Text PDFJ Dairy Sci
February 2024
Process Systems Engineering, School of Life Sciences, Technical University of Munich, 85354, Freising, Germany. Electronic address:
Lactose is typically produced via cooling crystallization either from whey or whey permeate (edible grade) or from aqueous solution (pharmaceutical grade). While in solution, lactose is present in 2 anomeric forms, α- and β-lactose. During cooling crystallization under standard process conditions, only α-lactose crystallizes, depleting the solution of α-anomer.
View Article and Find Full Text PDFJ Dairy Sci
September 2023
Food Process Engineering, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, the Netherlands; FrieslandCampina, Stationsplein 4, 3818 LE Amersfoort, the Netherlands.
Delactosed whey permeate is the mother liquor/by-product of lactose manufacture, but it still contains around 20 wt% lactose. The high mineral content, stickiness, and hygroscopic behavior prevent further recovery of lactose in the manufacturing process. Therefore, its use is currently limited to low-value applications such as cattle feed, and more often it is seen as waste.
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