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Susana Rubio-Arraez, Juan Vicente Capella, María Luisa Castelló, María Dolores Ortolá
In this study the effect of sweeteners with low glycemic index and non-cariogenic characteristics (isomaltulose, oligofructose and tagatose) in jelly prepared with citrus juice has been evaluated considering a citrus jelly formulated with sucrose as reference. The soluble solids, moisture content, pH, water activity, antioxidant capacity, optical and mechanical properties of jelly made using different sweeteners was determined during storage. Besides, mesophilic aerobics and moulds and yeasts was also counted to determine their stability over time...
October 2016: Journal of Food Science and Technology
Manisha J Patel, Rekha C Akhani, Arti T Patel, Samir R Dedania, Darshan H Patel
l-ribose and d-tagatose are biochemically synthesized using sugar isomerases. The l-arabinose isomerase gene from Shigella flexneri (Sf-AI) was cloned and expressed in Escherichia coli BL-21. Sf-AI was applied for the bioproduction of d-tagatose from d-galactose. l-ribose synthesis was performed by two step isomerization using Sf-AI and d-lyxose/ribose isomerase from Cohnella laevoribosii. The overall 22.3% and 25% conversion rate were observed for d-tagatose and l-ribose production from d-galactose and l-arabinose respectively...
February 2017: Enzyme and Microbial Technology
Jiangang Yang, Yueming Zhu, Yan Men, Shangshang Sun, Yan Zeng, Ying Zhang, Yuanxia Sun, Yanhe Ma
Rare sugars are valuable natural products widely used in pharmaceutical and food industries. In this study, we expected to synthesize rare ketoses from abundant glycerol using dihydroxyacetone phosphate (DHAP)-dependent aldolases. First, a new glycerol assimilation pathway was constructed to synthesize DHAP. The enzymes which convert glycerol to 3-hydroxypropionaldehyde and l-glyceraldehyde were selected, and their corresponding aldehyde synthesis pathways were constructed in vivo. Four aldol pathways based on different aldolases and phosphorylase were gathered...
December 21, 2016: Journal of Agricultural and Food Chemistry
Qinglong Wu, Nagendra P Shah
Residual lactose and galactose in fermented dairy foods leads to several industrial and health concerns. There is very little information pertaining to manufacture of fermented dairy foods that are low in lactose and galactose. In the present study, comparative genomic survey demonstrated the constant presence of chromosome-encoded tagatose-6-phosphate (T6P) pathway in Lactobacillus casei group. Lactose/galactose utilization tests and β-galactosidase assay suggest that PTS(Gal) system, PTS(Lac) system and T6P pathway are major contributors for lactose/galactose catabolism in this group of organisms...
April 2017: Food Microbiology
Ilenia Idda, Nadia Spano, Marco Ciulu, Valeria M Nurchi, Angelo Panzanelli, Maria I Pilo, Gavino Sanna
Saccharides are functional constituents of milk. Although d-lactose represents almost the totality of the saccharides in the milk, minor species, like d-glucose, d-galactose, myo-inositol and, as a result of severe thermal treatments, monosaccharides like d-tagatose, are also detectable. Although chromatography has been the main analytical approach used for accomplishing this task, quite surprisingly a validated gas chromatographic method aimed at the simultaneous determination of these compounds is still needed...
December 2016: Journal of Separation Science
Kyung-Chul Shin, Dong-Hyun Sim, Min-Ju Seo, Deok-Kun Oh
The generally recognized as safe microorganism Corynebacterium glutamicum expressing Geobacillus thermodenitrificans d-galactose isomerase (d-GaI) was an efficient host for the production of d-tagatose, a functional sweetener. The d-tagatose production at 500 g/L d-galactose by the host was 1.4-fold higher than that by Escherichia coli expressing d-GaI. The d-tagatose-producing activity of permeabilized C. glutamicum (PCG) cells treated with 1% (w/v) Triton X-100 was 2.1-fold higher than that of untreated cells...
November 2, 2016: Journal of Agricultural and Food Chemistry
Celina Bermúdez, Isabel Peña, Santiago Mata, José L Alonso
The conformational behaviour of naturally occurring ketohexoses has been revealed in a supersonic expansion by Fourier transform microwave spectroscopy coupled with a laser ablation source. Three, two and one conformers of d-tagatose, d-psicose and l-sorbose, respectively, have been identified by their rotational constants extracted from the analysis of the spectra. Singular structural signatures involving the hydroxyl groups OH(1) and OH(2) have been disentangled from the intricate intramolecular hydrogen bond networks stabilising the most abundant conformers...
November 14, 2016: Chemistry: a European Journal
Wei Xu, Chen Fan, Tao Zhang, Bo Jiang, Wanmeng Mu
L-Arabinose isomerase (L-AI, EC catalyzes the isomerization between L-arabinose and L-ribulose, and most of the reported ones can also catalyze D-galactose to D-tagatose, except Bacillus subtilis L-AI. In this article, the L-AI from the psychrotolerant bacterium Pseudoalteromonas haloplanktis ATCC 14393 was characterized. The enzyme showed no substrate specificity toward D-galactose, which was similar to B. subtilis L-AI but distinguished from other reported L-AIs. The araA gene encoding the P. haloplanktis L-AI was cloned and overexpressed in E...
November 2016: Molecular Biotechnology
Liuqing Wen, Kenneth Huang, Yuan Zheng, Junqiang Fang, Shukkoor Muhammed Kondengaden, Peng George Wang
Rare sugars offer a plethora of applications in the pharmaceutical, medicinal, and industries, as well as in synthetic chemistry. However, studies of rare sugars have been hampered by their relative scarcity. In this work, we describe a two-step strategy to efficiently and conveniently prepare 6-deoxy-L-psicose from L-rhamnose. In the first reaction step, the isomerization of L-rhamnose (6-deoxy-L-mannose) to L-rhamnulose (6-deoxy-L-fructose) catalyzed by L-rhamnose isomerase (RhaI), and the epimerization of L-rhamnulose to 6-deoxy-L-psicose catalyzed by D-tagatose 3-epimerase (DTE) were coupled with selective phosphorylation reaction by fructose kinase from human (HK), which selectively phosphorylate 6-deoxy-L-psicose at C-1 position...
August 24, 2016: Tetrahedron Letters
Liuqing Wen, Kenneth Huang, Yuan Zheng, Yunpeng Liu, He Zhu, Peng George Wang
A two-step enzymatic strategy for the efficient and convenient synthesis of 6-deoxy-l-sorbose was reported herein. In the first reaction step, the isomerization of l-fucose (6-deoxy-l-galactose) to l-fuculose (6-deoxy-l-tagatose) catalyzed by l-fucose isomerase (FucI), and the epimerization of l-fuculose to 6-deoxy-l-sorbose catalyzed by d-tagatose 3-epimerase (DTE) were coupled with the targeted phosphorylation of 6-deoxy-l-sorbose by fructose kinase from human (HK) in a one-pot reaction. The resultant 6-deoxy-l-sorbose 1-phosphate was purified by silver nitrate precipitation method...
September 1, 2016: Bioorganic & Medicinal Chemistry Letters
Hiromi Yoshida, Akihide Yoshihara, Tomohiko Ishii, Ken Izumori, Shigehiro Kamitori
Pseudomonas cichorii D-tagatose 3-epimerase (PcDTE), which has a broad substrate specificity, efficiently catalyzes the epimerization of not only D-tagatose to D-sorbose but also D-fructose to D-psicose (D-allulose) and also recognizes the deoxy sugars as substrates. In an attempt to elucidate the substrate recognition and catalytic reaction mechanisms of PcDTE for deoxy sugars, the X-ray structures of the PcDTE mutant form with the replacement of Cys66 by Ser (PcDTE_C66S) in complexes with deoxy sugars were determined...
December 2016: Applied Microbiology and Biotechnology
Wending Mei, Lu Wang, Ying Zang, Zhaojuan Zheng, Jia Ouyang
BACKGROUND: L-arabinose isomerase (AI) is a crucial catalyst for the biotransformation of D-galactose to D-tagatose. In previous reports, AIs from thermophilic bacterial strains had been wildly researched, but the browning reaction and by-products formed at high temperatures restricted their applications. By contrast, AIs from mesophilic Bacillus strains have some different features including lower optimal temperatures and lower requirements of metallic cofactors. These characters will be beneficial to the development of a more energy-efficient and safer production process...
2016: BMC Biotechnology
Robert-Jan van Putten, Jan C van der Waal, Martin Harmse, Henk H van de Bovenkamp, Ed de Jong, Hero J Heeres
The acid-catalysed dehydration of the four 2-ketohexoses (fructose, sorbose, tagatose and psicose) to furanics was studied in methanol (65 g L(-1) substrate concentration, 17 and 34 mm sulfuric acid, 100 °C) with Avantium high-throughput technology. Significant differences in the reactivities of the hexoses and yields of 5-hydroxymethylfurfural (HMF) and its methyl ether (MMF) were observed. Psicose and tagatose were the most reactive, and psicose also afforded the highest combined yield of MMF and HMF of approximately 55 % at 96 % sugar conversion...
July 21, 2016: ChemSusChem
Christelle F Iskandar, Catherine Cailliez-Grimal, Abdur Rahman, Emmanuel Rondags, Benoît Remenant, Monique Zagorec, Jorgen J Leisner, Frédéric Borges, Anne-Marie Revol-Junelles
The dairy population of Carnobacterium maltaromaticum is characterized by a high diversity suggesting a high diversity of the genetic traits linked to the dairy process. As lactose is the main carbon source in milk, the genetics of lactose metabolism was investigated in this LAB. Comparative genomic analysis revealed that the species C. maltaromaticum exhibits genes related to the Leloir and the tagatose-6-phosphate (Tagatose-6P) pathways. More precisely, strains can bear genes related to one or both pathways and several strains apparently do not contain homologs related to these pathways...
September 2016: Food Microbiology
Kim-Anne Lê, Frédéric Robin, Olivier Roger
PURPOSE OF REVIEW: Dietary sugars play a role in noncommunicable diseases and represent a clear target for reduction. In this context, product reformulation can have a positive impact on health. Several technological solutions are available to replace sugar, all with benefits and limitations. The goal of this review is to describe the main sugar replacement alternatives and discuss their impact on health and product physicochemical properties. RECENT FINDINGS: Although high intensity sweeteners and polyols have been used for a long time to replace sucrose and despite no clear evidence of harm, the trend is today to look for alternatives such as sweet enhancers or alternative sugars such as allulose or tagatose, which are both low caloric...
July 2016: Current Opinion in Clinical Nutrition and Metabolic Care
Desirée Hao, M Omair Sarfaraz, Farshad Farshidfar, D Gwyn Bebb, Camelia Y Lee, Cynthia M Card, Marilyn David, Aalim M Weljie
Lung cancer causes more deaths in men and women than any other cancer related disease. Currently, few effective strategies exist to predict how patients will respond to treatment. We evaluated the serum metabolomic profiles of 25 lung cancer patients undergoing chemotherapy ± radiation to evaluate the feasibility of metabolites as temporal biomarkers of clinical outcomes. Serial serum specimens collected prospectively from lung cancer patients were analyzed using both nuclear magnetic resonance ((1)H-NMR) spectroscopy and gas chromatography mass spectrometry (GC-MS)...
2016: Metabolomics: Official Journal of the Metabolomic Society
Lena Stellmacher, Tatyana Sandalova, Sarah Schneider, Gunter Schneider, Georg A Sprenger, Anne K Samland
Transaldolase B (TalB) and D-fructose-6-phosphate aldolase A (FSAA) from Escherichia coli are C-C bond-forming enzymes. Using kinetic inhibition studies and mass spectrometry, it is shown that enzyme variants of FSAA and TalB that exhibit D-fructose-6-phosphate aldolase activity are inhibited covalently and irreversibly by D-tagatose 6-phosphate (D-T6P), whereas no inhibition was observed for wild-type transaldolase B from E. coli. The crystal structure of the variant TalB(F178Y) with bound sugar phosphate was solved to a resolution of 1...
April 2016: Acta Crystallographica. Section D, Structural Biology
Wojciech Plazinski, Anita Plazinska, Mateusz Drach
The molecular properties of aldohexoses and ketohexoses are usually studied in the context of their cyclic, furanose or pyranose structures which is due to the abundance of related tautomeric forms in aqueous solution. We studied the conformational features of a complete series of D-aldohexoses (D-allose, D-altrose, D-glucose, D-mannose, D-gulose, d-idose, D-galactose and D-talose) and D-ketohexoses (D-psicose, D-fructose, D-sorbose and D-tagatose) as well as of L-psicose by using microsecond-timescale molecular dynamics in explicit water and DMSO with the use of enhanced sampling methods...
April 14, 2016: Physical Chemistry Chemical Physics: PCCP
Jin Myung Choi, Yong-Jik Lee, Thinh-Phat Cao, Sun-Mi Shin, Min-Kyu Park, Han-Seung Lee, Eric di Luccio, Seong-Bo Kim, Sang-Jae Lee, Sang Jun Lee, Sung Haeng Lee, Dong-Woo Lee
Thermophilic l-arabinose isomerase (AI), which catalyzes the interconversion of l-arabinose and l-ribulose, can be used to produce d-tagatose, a sugar substitute, from d-galactose. Unlike mesophilic AIs, thermophilic AIs are highly dependent on divalent metal ions for their catalytic activity and thermostability at elevated temperatures. However, the molecular basis underlying the substrate preferences and metal requirements of multimeric AIs remains unclear. Here we report the first crystal structure of the apo and holo forms of thermophilic Geobacillus kaustophilus AI (GKAI) in hexamer form...
April 15, 2016: Archives of Biochemistry and Biophysics
Manisha J Patel, Arti T Patel, Rekha Akhani, Samir Dedania, Darshan H Patel
Pseudomonas aeruginosa PAO1 phosphoglucose isomerase was purified as an active soluble form by a single-step purification using Ni-NTA chromatography that showed homogeneity on SDS-PAGE with molecular mass ∼62 kDa. The optimum temperature and pH for the maximum isomerization activity with D-galactose were 60 °C and 7.0, respectively. Generally, sugar phosphate isomerases show metal-independent activity but PA-PGI exhibited metal-dependent isomerization activity with aldosugars and optimally catalyzed the D-galactose isomerization in the presence of 1...
July 2016: Applied Biochemistry and Biotechnology
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