Rapid determination of lactulose in milk by microdialysis and biosensors

Moscone, Danila; Bernardo, Ricardo Alves; Marconi, Emanuele; Amine, Aziz; Palleschi, Giuseppe

doi:10.1039/a808535h

Cited by 49 publications

(32 citation statements)

References 26 publications

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“…Lactulose is often determined by the enzymatic methods using commercially available kits supplied by companies such as Boehringer-Mannheim and Merck. An enzymatic electrochemical method for the detection of lactulose content in milk samples was developed by Moscone et al [30]. This method uses the enzyme β-galactosidase in solution to hydrolyze lactulose to galactose and fructose, and then the latter is oxidized by a fructose dehydrogenase enzyme reactor using potassium ferricyanide as mediator and platinum-based electrochemical transducer.…”

Section: Enzymatic Methodsmentioning

confidence: 99%

Advances in Fractionation and Analysis of Milk Carbohydrates

Nagaraj¹,

Upadhyay²,

Nath³

et al. 2018

Technological Approaches for Novel Applications in Dairy Processing

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Lactose is a principal component of the milk obtained from the mammals. Milk also contains several other sugars such as monosaccharides and oligosaccharides in low concentrations. Lactose has reactive functional groups and can be converted to valuable food-grade derivatives for commercial applications through chemical and/or enzymatic reactions. Physical and chemical properties of carbohydrates determine the methods that can be used for their fractionation and purification. In this chapter, the advanced extraction techniques for fractionation and analytical methodologies applied for the determination of different carbohydrates of milk (lactose, lactulose, and oligosaccharides) are summarized.The main aim of this contribution is to provide the reader with a broad view on the recent fractionation and analytical techniques employed for the analysis of carbohydrates in dairy foods and their applications in food and pharmaceutical industry.

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Section: Enzymatic Methodsmentioning

confidence: 99%

Advances in Fractionation and Analysis of Milk Carbohydrates

Nagaraj¹,

Upadhyay²,

Nath³

et al. 2018

Technological Approaches for Novel Applications in Dairy Processing

View full text Add to dashboard Cite

show abstract

“…The enzyme can be immobilized directly on the electrode surface either by entrapment in carbon pastes (Paredes et al, 1997;Stredansky et al, 1999) or by cross-linking with glutaraldehyde (Hanke et al, 1996;Moscone et al, 1999;Xie et al, 1991). The sensors showed a linear response to fructose in the concentration range from 0.0036 g/L to 0.36 g/L (0.02 to 2 mM) (Matsumoto et al, 1986) with response times of about 1 min (Stredansky et al, 1999) and a loss of activity of 37% after 57 days (Hanke et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Development of a rapid, quantitative glucosyltransferase assay based on a screen‐printed fructose enzyme electrode and application to optimization studies on gtfD expression in recombinant Escherichia coli

Kadow

Betiku²,

Rinas³

et al. 2005

Biotech & Bioengineering

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A biosensor for fructose determination was used as basis of an assay for the determination of glucosyltransferase (GTF) activities and applied to monitoring recombinant enzyme production. GTFs catalyze the synthesis of glucans from sucrose leading to the release of fructose. Specific fructose determinations in the microM concentration range were achieved with a fructose electrode based on fructose dehydrogenase, which was immobilized on a screen-printed platinum electrode. This electrode was used as basis of the new assay for GTF activity determinations. Depending on the amount of enzyme, the assay was completed within 15-30 min compared to 1-2 h for the traditional photometric assay. From the amount of fructose released in a given reaction time, GTF activities were determined down to approx. 20 U/L. Even unpurified samples from a recombinant GTF-S production process could be analyzed without any problems, and a good correlation was obtained to data obtained from the photometric assay. Analysis of samples from cultures of various rGTF-S-producing recombinant E. coli strains grown on different media with SDS-PAGE and with the new assay identified the same strain and culture medium as optimum for recombinant GTF-S production.

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“…Thus, an enzymatic spectrophotometric assay entailing the use of b-galactosidase (b-Gal), which hydrolyses lactulose giving fructose and galactose, and fructose dehydrogenase (FDH) which reacts with fructose in the presence of a tetrazolium salt giving a colored compound which can be detected at 570 nm, has been reported [9]. A flow system was developed by immobilizing b-Gal in a reactor, and the amount of fructose produced was measured with an electrochemical biosensor based on FDH, K 3 [Fe(CN) 6 ] as mediator and a Pt based electrochemical transducer [10]. Moreover, the automated determination of lactulose in milk using an enzyme reactor and flow analysis with integrated dialysis has been reported [3].…”

Section: Introductionmentioning

confidence: 99%

A Lactulose Bienzyme Biosensor Based on Self‐Assembled Monolayer Modified Electrodes

Campuzano¹,

Pedrero²,

Villena³

et al. 2004

Electroanalysis

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A bienzyme biosensor in which the enzymes b-galactosidase (b-Gal), fructose dehydrogenase (FDH), and the mediator tetrathiafulvalene (TTF) were coimmobilized by cross-linking with glutaraldehyde atop a 3-mercaptopropionic acid (MPA) self-assembled monolayer on a gold disk electrode, is reported. The working conditions selected were E app ¼ þ 0.10 V and (25 AE 1) 8C. The useful lifetime of one single TTF-b-Gal-FDH-MPA-AuE was surprisingly long, 81 days. A linear calibration plot was obtained for lactulose over the 3.0 Â 10 À5 ± 1.0 Â 10 À3 mol L À1 concentration range, with a limit of detection of 9.6 Â 10 À6 mol L À1. The effect of potential interferents (lactose, glucose, galactose, sucrose, and ascorbic acid) on the biosensor response was evaluated. The behavior of the SAM-based biosensor in flow-injection systems in connection with amperometric detection was tested. The analytical usefulness of the biosensor was evaluated by determining lactulose in a pharmaceutical preparation containing a high lactulose concentration, and in different types of milk. Finally, the analytical characteristics of the TTF-b-Gal-FDH-MPA-AuE are critically compared with those reported for other recent enzymatic determinations of lactulose.

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Rapid determination of lactulose in milk by microdialysis and biosensors

Cited by 49 publications

References 26 publications

Advances in Fractionation and Analysis of Milk Carbohydrates

Advances in Fractionation and Analysis of Milk Carbohydrates

Development of a rapid, quantitative glucosyltransferase assay based on a screen‐printed fructose enzyme electrode and application to optimization studies on gtfD expression in recombinant Escherichia coli

A Lactulose Bienzyme Biosensor Based on Self‐Assembled Monolayer Modified Electrodes

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