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A recombinant L-arabinose isomerase from Enterococcus faecium DBFIQ E36 was immobilized onto multifunctional epoxide supports by chemical adsorption and onto a chelate-activated support via polyhistidine-tag, located on the N-terminal (N-His-L-AI) or on the C-terminal (C-His-L-AI) sequence, followed by covalent bonding between the enzyme and the support. The results were compared to reversible L-AI immobilization by adsorption onto charged agarose supports with improved stability. All the derivatives presented immobilization yields of above 75%. The ionic interaction established between agarose gels containing monoaminoethyl-N-aminoethyl structures (MANAE) and the enzyme was the most suitable strategy for L-AI immobilization in comparison to the chelate-activated agarose. In addition, the immobilized biocatalysts by ionic interaction in MANAE showed to be the most stable, retaining up to 100% of enzyme activity for 60 min at 60 °C and with Km values of 28 and 218 mM for MANAE-N-His-L-AI and MANAE-C-His-L-AI, respectively.

L-Arabinose isomerase (EC 5.3.1.4) (l-AI) from Enterococcus faecium DBFIQ E36 was overproduced in Escherichia coli by designing a codon-optimized synthetic araA gene. Using this optimized gene, two N- and C-terminal His-tagged-l-AI proteins were produced. The cloning of the two chimeric genes into regulated expression vectors resulted in the production of high amounts of recombinant N-His-l-AI and C-His-l-AI in soluble and active forms. Both His-tagged enzymes were purified in a single step through metal-affinity chromatography and showed different kinetic and structural characteristics. Analytical ultracentrifugation revealed that C-His-L-AI was preferentially hexameric in solution, whereas N-His-L-AI was mainly monomeric. The specific activity of the N-His-L-AI at acidic pH was higher than that of C-His-l-AI and showed a maximum bioconversion yield of 26% at 50 °C for d-tagatose biosynthesis, with Km and Vmax parameters of 252 mM and 0.092 U mg−1, respectively. However, C-His-L-AI was more active and stable at alkaline pH than N-His-L-AI. N-His-L-AI follows a Michaelis-Menten kinetic, whereas C-His-l-AI fitted to a sigmoidal saturation curve.

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on the energy conversion factor of D-tagatose to be used for calculating the energy value of foods to be declared in nutrition labelling. Energy conversion factors for nutrients for the purpose of nutrition labelling have been set based on the concept of metabolisable energy (ME). The same methodology has been applied to calculate the energy conversion factor for D-tagatose in this opinion. The assessment is based on a dossier prepared for Nutrilab NV and submitted by Bioresco Ltd. At present, data are insufficient to derive an accurate ME value for D-tagatose. Relying on the human data indicating a mean absorption rate of 80% (range 69–88%) and a urinary excretion of either 1% or 5%, the corresponding energy values for D-tagatose would be 2.8 kcal/g (11.8 kJ/g) and 2.96 kcal/g (12.4 kJ/g), respectively. Taking into account that the remaining 20% of D-tagatose which is not absorbed in the small intestine is fermented in the colon and may deliver at least some energy, e.g. in form of short-chain fatty acids, the Panel concludes that a rounded estimate of the energy conversion factor for D-tagatose based on the available data and calculated as ME would be 3 kcal/g (12.5 kJ/g). The Panel considers that additional data on the absorption, distribution, metabolism and excretion of D-tagatose in humans would help in the calculation of a more accurate energy conversion factor for D-tagatose based on the concept of ME.

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on the energy conversion factor of D-tagatose to be used for calculating the energy value of foods to be declared in nutrition labelling. Energy conversion factors for nutrients for the purpose of nutrition labelling have been set based on the concept of metabolisable energy (ME). The same methodology has been applied to calculate the energy conversion factor for D-tagatose in this opinion. The assessment is based on a dossier prepared for Nutrilab NV and submitted by Bioresco Ltd. At present, data are insufficient to derive an accurate ME value for D-tagatose. Relying on the human data indicating a mean absorption rate of 80% (range 69–88%) and a urinary excretion of either 1% or 5%, the corresponding energy values for D-tagatose would be 2.8 kcal/g (11.8 kJ/g) and 2.96 kcal/g (12.4 kJ/g), respectively. Taking into account that the remaining 20% of D-tagatose which is not absorbed in the small intestine is fermented in the colon and may deliver at least some energy, e.g. in form of short-chain fatty acids, the Panel concludes that a rounded estimate of the energy conversion factor for D-tagatose based on the available data and calculated as ME would be 3 kcal/g (12.5 kJ/g). The Panel considers that additional data on the absorption, distribution, metabolism and excretion of D-tagatose in humans would help in the calculation of a more accurate energy conversion factor for D-tagatose based on the concept of ME.

A new isomerization reaction was developed to synthesize rare ketoses. d-Tagatose, d-xylulose, and d-ribulose were obtained in the maximum yields of 24%, 38%, and 40%, respectively, from the corresponding aldoses, d-galactose, d-xylose, and d-ribose, by treating the aldoses with 80% (v/v) subcritical aqueous ethanol at 180°C. The maximum productivity of d-tagatose was ca. 80g/(Lh). Increasing the concentration of ethanol significantly increased the isomerization of d-galactose. Variation in the reaction temperature did not significantly affect the production of d-tagatose from d-galactose. Subcritical aqueous ethanol converted both 2, 3-threo and 2, 3-erythro aldoses to the corresponding C-2 ketoses in high yields. Thus, the treatment of common aldoses in subcritical aqueous ethanol can be regarded as a new method to synthesize the corresponding rare sugars.

D-Tagatose is partly absorbed in the stomach and small intestine. Most of it is fermented by the large intestinal microbiota. The effect of D-tagatose on the composition of the microbiota and production of short chain fatty acids (SCFAs) was studied in vivo and in vitro. Gastrointestinal (GI) complaints were also studied. The in vivo study was performed according to a randomized, placebo-controlled, double-blind, five-way cross-over design in healthy subjects (12 men and 18 women). All subjects consumed 30 g raspberry jam containing 7.5 or 12.5 g D-tagatose, 7.8 g fructo-oligosaccharides (positive reference), 7.6 g D-tagatose plus 7.5 g fructo-oligosaccharides, or 15.1 g sucrose (negative reference) at breakfast for 2 weeks in different orders. At the end of each treatment period lipids and safety parameters in blood and GI complaints were evaluated by questionnaires, and faecal microbiota and SCFAs were measured. Furthermore, test-tube incubations of faecal slurries with D-tagatose, fructo-oligosaccharides and sucrose were performed. An in vitro model simulating the large intestine was used to assess the mechanistic effect of D-tagatose on microbiota composition and SCFA production. The high-tagatose treatment resulted in increased numbers of faecal lactobacilli in men, but not in women. Also in vitro, lactobacilli increased. Both the test-tube incubations of fresh faeces from the in vivo study with D-tagatose and the study in the in vitro model showed increased butyrate production after all treatments with D-tagatose. High-tagatose, but not low-tagatose, resulted in a slightly increased defecation frequency and stools of thinner consistency. Only a few GI complaints were reported. The data indicate that daily consumption of 7.5 or 12.5 g D-tagatose may lead to increased production of butyrate and to an increase of lactobacilli, without serious GI complaints. In view of the health-promoting effects of butyrate and lactobacilli, D-tagatose may be considered a prebio

Toto sladidlo D-tagatosa, má četné výhody, které by se časem i u nás mohly využívat v potravinovém průmysle. Jsou zde shrnuty vlastnosti D-tagatosy, fyzikální také chemické a možnosti výroby D-tagatosy. V základních informacích o vlastnostech se také pojednává o samotném metabolismu D-tagatosy a jejich prebiotických vlastnostech v trávicím traktu. D-tagatosa je nově navržené náhradní sladidlo, také proto nesmí chybět možnost aplikace D-tagatosy v potravinách jako jsou např. cukrovinky. Vlastnosti D-tagatosy jsou porovnány se sladivostí klasického cukru. Nedílnou součástí je také možnost stanovení D-tagatosy v potravinách různými metodami a technikami., This sweetener, D-tagatose, has numerous advantages, which would eventually be able to use in the food industry. It summarizes the properties of Dtagatose, physical and also chemical, the possibility of production from lactose or bacterial action on Dtalitol. The basic information about the properties of Dtagatosy also discusses the actual metabolism of Dtagatose, prebiotic properties and their effect in the gastrointestinal tract. Dtagatose is a proposed new sweetener, because the possibility can not be missed in certain applications tagatose in a different types of foods for example confectionery. And positive qualities in comparison with sucrose. This comparison is made to examples of disease associated with excessive use of conventional sweeteners sucrose. This paper also discusses possibilities Dtagatose determination in foods by different methods.

Toto sladidlo D-tagatosa, má četné výhody, které by se časem i u nás mohly využívat v potravinovém průmysle. Jsou zde shrnuty vlastnosti D-tagatosy, fyzikální také chemické a možnosti výroby D-tagatosy. V základních informacích o vlastnostech se také pojednává o samotném metabolismu D-tagatosy a jejich prebiotických vlastnostech v trávicím traktu. D-tagatosa je nově navržené náhradní sladidlo, také proto nesmí chybět možnost aplikace D-tagatosy v potravinách jako jsou např. cukrovinky. Vlastnosti D-tagatosy jsou porovnány se sladivostí klasického cukru. Nedílnou součástí je také možnost stanovení D-tagatosy v potravinách různými metodami a technikami., This sweetener, D-tagatose, has numerous advantages, which would eventually be able to use in the food industry. It summarizes the properties of Dtagatose, physical and also chemical, the possibility of production from lactose or bacterial action on Dtalitol. The basic information about the properties of Dtagatosy also discusses the actual metabolism of Dtagatose, prebiotic properties and their effect in the gastrointestinal tract. Dtagatose is a proposed new sweetener, because the possibility can not be missed in certain applications tagatose in a different types of foods for example confectionery. And positive qualities in comparison with sucrose. This comparison is made to examples of disease associated with excessive use of conventional sweeteners sucrose. This paper also discusses possibilities Dtagatose determination in foods by different methods.

Toto sladidlo D-tagatosa, má četné výhody, které by se časem i u nás mohly využívat v potravinovém průmysle. Jsou zde shrnuty vlastnosti D-tagatosy, fyzikální také chemické a možnosti výroby D-tagatosy. V základních informacích o vlastnostech se také pojednává o samotném metabolismu D-tagatosy a jejich prebiotických vlastnostech v trávicím traktu. D-tagatosa je nově navržené náhradní sladidlo, také proto nesmí chybět možnost aplikace D-tagatosy v potravinách jako jsou např. cukrovinky. Vlastnosti D-tagatosy jsou porovnány se sladivostí klasického cukru. Nedílnou součástí je také možnost stanovení D-tagatosy v potravinách různými metodami a technikami., This sweetener, D-tagatose, has numerous advantages, which would eventually be able to use in the food industry. It summarizes the properties of Dtagatose, physical and also chemical, the possibility of production from lactose or bacterial action on Dtalitol. The basic information about the properties of Dtagatosy also discusses the actual metabolism of Dtagatose, prebiotic properties and their effect in the gastrointestinal tract. Dtagatose is a proposed new sweetener, because the possibility can not be missed in certain applications tagatose in a different types of foods for example confectionery. And positive qualities in comparison with sucrose. This comparison is made to examples of disease associated with excessive use of conventional sweeteners sucrose. This paper also discusses possibilities Dtagatose determination in foods by different methods.

Toto sladidlo D-tagatosa, má četné výhody, které by se časem i u nás mohly využívat v potravinovém průmysle. Jsou zde shrnuty vlastnosti D-tagatosy, fyzikální také chemické a možnosti výroby D-tagatosy. V základních informacích o vlastnostech se také pojednává o samotném metabolismu D-tagatosy a jejich prebiotických vlastnostech v trávicím traktu. D-tagatosa je nově navržené náhradní sladidlo, také proto nesmí chybět možnost aplikace D-tagatosy v potravinách jako jsou např. cukrovinky. Vlastnosti D-tagatosy jsou porovnány se sladivostí klasického cukru. Nedílnou součástí je také možnost stanovení D-tagatosy v potravinách různými metodami a technikami., This sweetener, D-tagatose, has numerous advantages, which would eventually be able to use in the food industry. It summarizes the properties of Dtagatose, physical and also chemical, the possibility of production from lactose or bacterial action on Dtalitol. The basic information about the properties of Dtagatosy also discusses the actual metabolism of Dtagatose, prebiotic properties and their effect in the gastrointestinal tract. Dtagatose is a proposed new sweetener, because the possibility can not be missed in certain applications tagatose in a different types of foods for example confectionery. And positive qualities in comparison with sucrose. This comparison is made to examples of disease associated with excessive use of conventional sweeteners sucrose. This paper also discusses possibilities Dtagatose determination in foods by different methods.

Toto sladidlo D-tagatosa, má četné výhody, které by se časem i u nás mohly využívat v potravinovém průmysle. Jsou zde shrnuty vlastnosti D-tagatosy, fyzikální také chemické a možnosti výroby D-tagatosy. V základních informacích o vlastnostech se také pojednává o samotném metabolismu D-tagatosy a jejich prebiotických vlastnostech v trávicím traktu. D-tagatosa je nově navržené náhradní sladidlo, také proto nesmí chybět možnost aplikace D-tagatosy v potravinách jako jsou např. cukrovinky. Vlastnosti D-tagatosy jsou porovnány se sladivostí klasického cukru. Nedílnou součástí je také možnost stanovení D-tagatosy v potravinách různými metodami a technikami., This sweetener, D-tagatose, has numerous advantages, which would eventually be able to use in the food industry. It summarizes the properties of Dtagatose, physical and also chemical, the possibility of production from lactose or bacterial action on Dtalitol. The basic information about the properties of Dtagatosy also discusses the actual metabolism of Dtagatose, prebiotic properties and their effect in the gastrointestinal tract. Dtagatose is a proposed new sweetener, because the possibility can not be missed in certain applications tagatose in a different types of foods for example confectionery. And positive qualities in comparison with sucrose. This comparison is made to examples of disease associated with excessive use of conventional sweeteners sucrose. This paper also discusses possibilities Dtagatose determination in foods by different methods.

Toto sladidlo D-tagatosa, má četné výhody, které by se časem i u nás mohly využívat v potravinovém průmysle. Jsou zde shrnuty vlastnosti D-tagatosy, fyzikální také chemické a možnosti výroby D-tagatosy. V základních informacích o vlastnostech se také pojednává o samotném metabolismu D-tagatosy a jejich prebiotických vlastnostech v trávicím traktu. D-tagatosa je nově navržené náhradní sladidlo, také proto nesmí chybět možnost aplikace D-tagatosy v potravinách jako jsou např. cukrovinky. Vlastnosti D-tagatosy jsou porovnány se sladivostí klasického cukru. Nedílnou součástí je také možnost stanovení D-tagatosy v potravinách různými metodami a technikami., This sweetener, D-tagatose, has numerous advantages, which would eventually be able to use in the food industry. It summarizes the properties of Dtagatose, physical and also chemical, the possibility of production from lactose or bacterial action on Dtalitol. The basic information about the properties of Dtagatosy also discusses the actual metabolism of Dtagatose, prebiotic properties and their effect in the gastrointestinal tract. Dtagatose is a proposed new sweetener, because the possibility can not be missed in certain applications tagatose in a different types of foods for example confectionery. And positive qualities in comparison with sucrose. This comparison is made to examples of disease associated with excessive use of conventional sweeteners sucrose. This paper also discusses possibilities Dtagatose determination in foods by different methods.

Toto sladidlo D-tagatosa, má četné výhody, které by se časem i u nás mohly využívat v potravinovém průmysle. Jsou zde shrnuty vlastnosti D-tagatosy, fyzikální také chemické a možnosti výroby D-tagatosy. V základních informacích o vlastnostech se také pojednává o samotném metabolismu D-tagatosy a jejich prebiotických vlastnostech v trávicím traktu. D-tagatosa je nově navržené náhradní sladidlo, také proto nesmí chybět možnost aplikace D-tagatosy v potravinách jako jsou např. cukrovinky. Vlastnosti D-tagatosy jsou porovnány se sladivostí klasického cukru. Nedílnou součástí je také možnost stanovení D-tagatosy v potravinách různými metodami a technikami., This sweetener, D-tagatose, has numerous advantages, which would eventually be able to use in the food industry. It summarizes the properties of Dtagatose, physical and also chemical, the possibility of production from lactose or bacterial action on Dtalitol. The basic information about the properties of Dtagatosy also discusses the actual metabolism of Dtagatose, prebiotic properties and their effect in the gastrointestinal tract. Dtagatose is a proposed new sweetener, because the possibility can not be missed in certain applications tagatose in a different types of foods for example confectionery. And positive qualities in comparison with sucrose. This comparison is made to examples of disease associated with excessive use of conventional sweeteners sucrose. This paper also discusses possibilities Dtagatose determination in foods by different methods.

Toto sladidlo D-tagatosa, má četné výhody, které by se časem i u nás mohly využívat v potravinovém průmysle. Jsou zde shrnuty vlastnosti D-tagatosy, fyzikální také chemické a možnosti výroby D-tagatosy. V základních informacích o vlastnostech se také pojednává o samotném metabolismu D-tagatosy a jejich prebiotických vlastnostech v trávicím traktu. D-tagatosa je nově navržené náhradní sladidlo, také proto nesmí chybět možnost aplikace D-tagatosy v potravinách jako jsou např. cukrovinky. Vlastnosti D-tagatosy jsou porovnány se sladivostí klasického cukru. Nedílnou součástí je také možnost stanovení D-tagatosy v potravinách různými metodami a technikami., This sweetener, D-tagatose, has numerous advantages, which would eventually be able to use in the food industry. It summarizes the properties of Dtagatose, physical and also chemical, the possibility of production from lactose or bacterial action on Dtalitol. The basic information about the properties of Dtagatosy also discusses the actual metabolism of Dtagatose, prebiotic properties and their effect in the gastrointestinal tract. Dtagatose is a proposed new sweetener, because the possibility can not be missed in certain applications tagatose in a different types of foods for example confectionery. And positive qualities in comparison with sucrose. This comparison is made to examples of disease associated with excessive use of conventional sweeteners sucrose. This paper also discusses possibilities Dtagatose determination in foods by different methods.