Quantification of lactose using ion-pair RP-HPLC during enzymatic lactose hydrolysis of skim milk

Erich, S.J.F.; Anzmann, Theresa; Fischer, Lutz

doi:10.1016/j.foodchem.2012.07.059

Cited by 34 publications

(18 citation statements)

References 16 publications

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“…Table 4 reports the obtained analytical data. The D-lactose amounts measured in samples 1 and 2 are in good agreement with literature data [29] for skimmed milk. Moreover, the comparison between the typical range of lactose concentrations for whole milk [1,30] suggests that the skimming process does not significantly change the lactose concentration.…”

Section: Application To Real Samplessupporting

confidence: 89%

Gas chromatography analysis of major free mono‐ and disaccharides in milk: Method assessment, validation, and application to real samples

Idda

Spano

Ciulu

et al. 2016

J of Separation Science

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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. Hence, our contribution is devoted to fill this gap. After the optimization of clean-up and derivatization (conversion of saccharides in their trimethyl silyl ethers) steps, the adoption of a highly cross-linked silphenylene stationary phase permitted to obtain high resolution and a fast chromatographic run. Validation was accomplished in terms of limit of detection, limit of quantification, linearity, precision, and trueness. The accuracy of the method was successfully tested on a number of partially skimmed milk samples. Excellent limits of detection for all analytes make this method eligible, also with respect to a gas chromatographic/mass spectrometry approach, for routine analysis and quality control in the dairy industries.

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Section: Application To Real Samplessupporting

confidence: 89%

Gas chromatography analysis of major free mono‐ and disaccharides in milk: Method assessment, validation, and application to real samples

Idda

Spano

Ciulu

et al. 2016

J of Separation Science

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“…The separation of sugars was adapted from Erich et al (2012). The analysis temperature was 25°C and 20 mM tetrabutylammonium hydrogen sulfate (ion-pair reagent) in 50 mM sodium phosphate buffer pH 2.0 was used as an eluent (flow rate: 0.5 mL/min).…”

Section: Hplc Methods For Sugar Quantificationmentioning

confidence: 99%

Enzymatic production of lactulose and epilactose in milk

Rentschler

Schuh

Krewinkel

et al. 2015

Journal of Dairy Science

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The enzymatic production of lactulose was described recently through conversion of lactose by a thermophilic cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus (CsCE). In the current study, we examined the application of CsCE for lactulose and epilactose production in milk (1.5% fat). The bioconversions were carried out in stirred reaction vessels at 2 different temperatures (50 and 8°C) at a scale of 25 mL volume. At 50°C, 2 highly different CsCE amounts were investigated for the time course of formation of lactulose and epilactose. The conversion of milk lactose (initial lactose content of 48.5 ± 2.1 g/L) resulted in a final yield of 57.7% (28.0 g/L) lactulose and 15.5% (7.49 g/L) epilactose in the case of the approximately 9.5-fold higher CsCE amount (39.5 µkat epilactose, 50°C) after 24 h. Another enzymatic lactose conversion was carried out at low 8°C, an industrially relevant temperature for milk processing. Although the CsCE originated from a thermophilic microorganism, it was still applicable at 8°C. This enzymatic lactose conversion resulted in 56.7% (27.5 g/L) lactulose and 13.6% (6.57 g/L) epilactose from initial milk lactose after 72 h. The time courses of lactose conversion by CsCE suggested that first epilactose formed and afterward lactulose via epilactose. To the best of our knowledge, this is the first time that an enzyme has produced lactulose directly in milk in situ at industrially relevant temperatures.

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“…44,45 Analysis of diluted milk samples by SALDI-MS on weathering steel sample plates produced a clean spectrum for lactose and isobaric galactose/glucose in the case of lactase treated lactosefree milk (Fig. Particularly lactose is an important constituent of cow milk and, as a response to the widespread inherited intolerance against lactose among consumers, the dairy industry offers low-lactose and lactose free milk and derived products.…”

Section: Lactose Quantication In Milkmentioning

confidence: 99%

Nanostructured weathering steel for matrix-free laser desorption ionisation mass spectrometry and imaging of metabolites, drugs and complex glycans

Etxebarría

Calvo

Reichardt

2014

Analyst

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Weathering steel has been employed for the first time to prepare sample plates for matrix-free laser desorption ionisation mass spectrometry (LDI-MS) of small molecules up to a mass range of around 1500 Da. The effective UV absorption, heat conductivity and porosity of the nanostructured inner rust layer formed during passivation determine the excellent performance in LDI-MS for a broad range of different analyte classes. The inexpensive material was evaluated in a series of relevant analytical applications ranging from the matrix-free detection of serum metabolites, lactose quantification, lipid analysis in milk to the glycoprofiling of antibodies and imaging mass spectrometry of brain tissue samples.

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Quantification of lactose using ion-pair RP-HPLC during enzymatic lactose hydrolysis of skim milk

Cited by 34 publications

References 16 publications

Gas chromatography analysis of major free mono‐ and disaccharides in milk: Method assessment, validation, and application to real samples

Gas chromatography analysis of major free mono‐ and disaccharides in milk: Method assessment, validation, and application to real samples

Enzymatic production of lactulose and epilactose in milk

Nanostructured weathering steel for matrix-free laser desorption ionisation mass spectrometry and imaging of metabolites, drugs and complex glycans

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