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Established and Novel Excipients for Freeze-Drying of Proteins
Published in Davide Fissore, Roberto Pisano, Antonello Barresi, Freeze Drying of Pharmaceutical Products, 2019
Ivonne Seifert, Wolfgang Friess
Raffinose is composed of galactose, glucose, and fructose, but it is a nonreducing sugar owing to its chemical stability. It forms amorphous lyophilisates with a Tg′ of −26°C and a Tg of 109°C. Annealing at −10°C results in the crystalline raffinose pentahydrate form, which was dehydrated during primary drying and eventually became amorphous. LDH activity was reduced in the annealed samples, although the final product containing 5% to 14% raffinose was amorphous (Chatterjee et al. 2005b; Heljo 2013). The stabilising potential of raffinose via water replacement appears to be inferior to sucrose. Whereas 100% raffinose resulted in a markedly higher Tg of 37°C at approximately 5% residual moisture than sucrose and raffinose/sucrose mixtures, the remaining LDH activity was higher with higher sucrose content upon storage at 44°C for 45 days (Davidson and Sun 2001).
Ionic Liquids in Sustainable Carbohydrate Catalysis
Published in Pedro Lozano, Sustainable Catalysis in Ionic Liquids, 2018
Pilar Hoyos, Cecilia García-Oliva, María J. Hernáiz
Forsyth and co-workers described dicyanamide-based ionic liquids [BMIN] [DCA] and [EMIM] [DCA] (Figure 8.5) not only as effective solvents for saccharides, but also as active base catalysts for their O-acetylation (Forsyth et al., 2002). Different monosaccharides were acetylated under mild reactions conditions, employing acetic anhydride and those ILs as reaction media. Very high yields were achieved in all cases in very short reaction times. The protocol was successfully extended to the acylation of N-acetylneuraminic acid, sucrose, and the trisaccharide raffinose. The –N(CN)2 counterion seemed to be relevant, as the development of the process in other ILs with different anions, as bis(trifluoromethanesulfonyl)amide, ([BMIM] [Tfms]) failed to afford products.
Biomass Chemistry
Published in Jay J. Cheng, Biomass to Renewable Energy Processes, 2017
Disaccharides are part of a larger group called oligosaccharides, which consist of 2 to 10 monosaccharide units connected via glycosidic bonds. An example of an oligosaccharide is raffinose (Figure 2.17), which is a trisaccharide composed of galactose, fructose, and glucose units.
Microencapsulation of okara protein hydrolysate by spray drying: physicochemical and nutritive properties, sorption isotherm, and glass transition temperature
Published in Drying Technology, 2022
Ariana Justus, Elza Iouko Ida, Louise Emy Kurozawa
There were significant differences between all the samples (Table 2). Spray-dried products presented higher glucose content and lower oligosaccharide content than the control sample. Strong negative correlations between glucose, and raffinose and stachyose oligosaccharides were indicated by Pearson’s correlation coefficients of r = −0.86 and −0.83, respectively. Sugar hydrolysis could have been the cause of these sugar profile changes. It is possible that the spray-drying process favored the action of the endogenous α-galactosidase of soybeans, thereby converting the oligosaccharides, stachyose and raffinose, into sucrose. However, the sucrose content decreased after spray drying, indicating that sucrose could be converted to another compound. This may be related to the significant increase in glucose content after spray drying. A moderate negative correlation between sucrose and glucose was indicated by the Pearson’s correlation coefficient (r = −0.60).
Osmotic pretreatment for instant controlled pressure drop dried apple chips: Impact of the type of saccharides and treatment conditions
Published in Drying Technology, 2019
Min Xiao, Jinfeng Bi, Jianyong Yi, Yuanyuan Zhao, Jian Peng, Linyan Zhou, Qinqin Chen
Six different types of sugar solution were prepared for osmotic dehydration: two monosaccharides (fructose, glucose), two disaccharides (sucrose, maltose), a trisaccharide (raffinose), and a tetrasaccharide (stachyose) in concentration of 40% w/w. The osmotic solutions were prepared by blending the sugar with distilled water on a weight-to-weight basis and stirred at rotational speed of about 1 r/s to make the surface mass transfer resistance negligible. The ratio of fruit/syrup was 1:8 by weight, preventing significant alteration of syrup concentration during osmotic dehydration. The samples were taken out of the osmotic medium at time intervals of 30, 60, 90, 120, 180, and 240 min. Six pieces of the samples were removed at each intervals, then shaken manually, and put on plotting paper to eliminate superficial syrup and weighed. The WL and SG of the osmotically treated apple slices were calculated by the following equations:[20] where M0 and Mt are the initial and final sample mass (kg), respectively. Xw0 and Xwt are the initial and final sample moisture content (kg water/kg w. b.), respectively; and Xs0 and Xst are the initial and final sample total soluble solids content (kg solid/kg w. b.), respectively. All experiments were conducted in triplicate, and the average values were reported.
Production, purification, characterization, and applications of α-galactosidase from Bacillus flexus JS27 isolated from Manikaran hot springs
Published in Preparative Biochemistry & Biotechnology, 2023
Sonu Bhatia, Navneet Batra, Jagtar Singh
The enzyme hydrolyzes the α-1,6-linkage at the non-reducing end of the sugars resulting in the release of galactosyl residue from substrates (donor) like pNPG, melibiose, etc. Released galactosyl residue is then transferred to a suitable acceptor molecule (sorbitol) leading to the formation of α-galactooligosaccharides (GOS). Self-condensation reaction with pNPG resulted in the formation of transgalactosylation (pNPGT) (Figure 9A). Melibiose which is a disaccharide composed of glucose and galactose showed the formation of stachyose, raffinose, and galactose by enzymatic hydrolysis and transgalactosylation reactions (Figure 9B). Transgalactosylated products/GOS were formed with a mixture of pNPG: sorbitiol (1:1), melibiose: sorbitol (1:1) acting as separate donor and acceptor molecules (Figure 9C). Melibiose catalysis was checked by TLC followed by HPLC analysis (with appropriate control) which showed the appearance of a peak at 8.690 min in the test sample besides minor peaks (Figure 10) indicating the formation of GOS. JS27 α-Gal II depicted transgalactosylation reactions, similarly, such reactions were reported from α-galactosidase of Bacteroides fragilis, which transferred galactosyl residue from pNPG to lactose resulting in the synthesis of globotriose.[65] Similarly, MelA enzyme from Lactobacillus plantarum catalyzed melibiose to GOS (manninotriose).[66] In a study by Tzortis et al.,[46] α-Galactosidase obtained from Lactobacillus reutri formed α-D-Galp-(1,6)-α-D-Galp-(1,6)-α-D-Glcp using melibiose as substrate as indicated by HPLC peaks. Various studies have highlighted validation of transgalactosyled products using purification methodologies like gel permeation chromatography followed by their structural analysis employing NMR, MS, LC-MS.[67–70]