The Experts below are selected from a list of 1698 Experts worldwide ranked by ideXlab platform

Zbigniew Szewczuk - One of the best experts on this subject based on the ideXlab platform.

  • Intramolecularly stapled amphipathic peptides via a boron–sugar interaction
    Chemical Communications, 2020
    Co-Authors: Monika Kijewska, Piotr Stefanowicz, Łukasz Jaremko, Mariusz Jaremko, Mateusz Waliczek, Angelika Czerwińska, Samah Al-harthi, Grzegorz Wołczański, Abdul-hamid Emwas, Zbigniew Szewczuk
    Abstract:

    Amadori Products (deoxyfructosyllysine derivatives) that can selectively interact with phenylboronic acids and borate ions were synthesized. The intramolecular interactions between the fructosyl moiety and phenylboronic acid incorporated into various positions of the peptide chain were investigated using high-resolution mass spectrometry (HR–MS), circular dichroism (CD), and nuclear magnetic resonance (NMR).

  • DOI: 10.1007/s13361-014-0857-4 RESEARCH ARTICLE Selective Detection of Carbohydrates and Their Peptide Conjugates by ESI-MS Using Synthetic Quaternary Ammonium Salt Derivatives of Phenylboronic Acids
    2016
    Co-Authors: Zbigniew Szewczuk
    Abstract:

    Abstract. We present new tags based on the derivatives of phenylboronic acid and apply them for the selective detection of sugars and peptide-sugar conjugates in mass spectrometry. We investigated the binding of phenylboronic acid and its quaternary ammonium salt (QAS) derivatives to carbohydrates and peptide-derived Amadori Products by HR-MS and MS/MS experiments. The formation of complexes between sugar or sugar-peptide conjugates and synthetic tags was confirmed on the basis of the unique isotopic distribution resulting from the presence of boron atom. Moreover, incorporation of a quaternary ammonium salt dramatically improved the efficiency of ionization in mass spectrometry. It was found that the formation of a complex with phenylboronic acid stabilizes the sugar moiety in glycated peptides, resulting in simplification of the fragmentation pattern of peptide-derived Amadori Products. The obtained results suggest that derivatization of phenylboronic acid as QAS is a promising method for sensitive ESI-MS detection of carbohydrates and their conjugates formed by non-enzymatic glycation or glycosylation

  • Comparison of modification sites in glycated crystallin in vitro and in vivo
    2016
    Co-Authors: Martyna Kielmas, Piotr Stefanowicz, Alicja Kluczyk, Monika Kijewska, Jolanta Oficjalska, Bożena Gołębiewska, Zbigniew Szewczuk
    Abstract:

    Abstract Glycation ofα-crystallin is responsible for age- and diabetic-related cataracts, which are the main cause of blind-ness worldwide. We optimized the method of identification of lysine residues prone to glycation using the combination of LC-MS, isotopic labeling, and modified synthetic peptide standards with the glycated lysine derivative (Fmoc-Lys(i,i-Fru,Boc)-OH). The in vitro glycation of bovine lens α-crystallin was conducted by optimized method with the equi-molar mixture of [12C6]- and [ 13C6]D-glucose. The in vivo glycation was studied on human lens crystallin. The glycated protein was subjected to proteolysis and analyzed using LC-MS. The results of in vitro and in vivo glycation of α-crystallin reveal a different distribution of the modified lysine residues. More Amadori Products were detected as a result of the in vitro reaction due to forced glycation conditions. The developed method allowed us to identify the glycation sites in crystallin from eye lenses obtained from patients suffering from the cataract. We identified K166 in the A chain and K166 in the B chain of α-crystallin as major glycation sites during the in vitro reaction. We found also two in vivo glycated lysine residues: K92 in the B chain and K166 in the A chain, which are known as locations for Amadori Products. These modification sites were confirmed by the LC-MS experiment using two synthetic standards. This study demonstrates the applicability of the LC-MS methods com-bined with the isotopic labeling and synthetic peptide stan-dards for analysis of post-translational modifications in the biological material

  • Selective Detection of Carbohydrates and Their Peptide Conjugates by ESI-MS Using Synthetic Quaternary Ammonium Salt Derivatives of Phenylboronic Acids
    Journal of The American Society for Mass Spectrometry, 2014
    Co-Authors: Monika Kijewska, Piotr Stefanowicz, Alicja Kluczyk, Adam Kuc, Mateusz Waliczek, Aleksandra Man-kupisinska, Jolanta Lukasiewicz, Zbigniew Szewczuk
    Abstract:

    We present new tags based on the derivatives of phenylboronic acid and apply them for the selective detection of sugars and peptide-sugar conjugates in mass spectrometry. We investigated the binding of phenylboronic acid and its quaternary ammonium salt (QAS) derivatives to carbohydrates and peptide-derived Amadori Products by HR-MS and MS/MS experiments. The formation of complexes between sugar or sugar-peptide conjugates and synthetic tags was confirmed on the basis of the unique isotopic distribution resulting from the presence of boron atom. Moreover, incorporation of a quaternary ammonium salt dramatically improved the efficiency of ionization in mass spectrometry. It was found that the formation of a complex with phenylboronic acid stabilizes the sugar moiety in glycated peptides, resulting in simplification of the fragmentation pattern of peptide-derived Amadori Products. The obtained results suggest that derivatization of phenylboronic acid as QAS is a promising method for sensitive ESI-MS detection of carbohydrates and their conjugates formed by non-enzymatic glycation or glycosylation.

  • The isotopic exchange of oxygen as a tool for detection of the glycation sites in proteins.
    Analytical Biochemistry, 2011
    Co-Authors: Monika Kijewska, Piotr Stefanowicz, Alicja Kluczyk, Zbigniew Szewczuk
    Abstract:

    A nonenzymatic reaction of reducing sugars with the free amino group located at the N terminus of the polypeptide chain or in the lysine side chain results in glycation of proteins. The fragments of glycated proteins obtained by enzymatic hydrolysis could be considered as the biomarkers of both the aging process and diabetes mellitus. Here we propose a new method for the identification of peptide-derived Amadori Products in the enzymatic digest of glycated proteins. The Products of enzymatic hydrolysis of the model protein ubiquitin were incubated with H218O under microwave activation. We observed that at these conditions the Amadori compounds selectively exchange one oxygen atom in the hexose moiety. The characteristic isotopic pattern of Amadori Products treated with H218O allows fast and convenient identification of this group of compounds, whereas nonglycated peptides are not susceptible to isotopic exchange.

Vincenzo Fogliano - One of the best experts on this subject based on the ideXlab platform.

  • the quantification of free Amadori compounds and amino acids allows to model the bound maillard reaction Products formation in soybean Products
    Food Chemistry, 2018
    Co-Authors: Antonio Dario Troise, Vincenzo Fogliano, Markus Wiltafsky, Paola Vitaglione
    Abstract:

    The quantification of protein bound Maillard reaction Products (MRPs) is still a challenge in food chemistry. Protein hydrolysis is the bottleneck step: it is time consuming and the protein degradation is not always complete. In this study, the quantitation of free amino acids and Amadori Products (APs) was compared to the percentage of blocked lysine by using chemometric tools. Eighty thermally treated soybean samples were analyzed by mass spectrometry to measure the concentration of free amino acids, free APs and the protein-bound markers of the Maillard reaction (furosine, Ne-(carboxymethyl)-l-lysine, Ne-(carboxyethyl)-l-lysine, total lysine). Results demonstrated that Discriminant Analysis (DA) and Correlated Component Regression (CCR) correctly estimated the percent of blocked lysine in a validation and prediction set. These findings indicate that the measure of free markers reflects the extent of protein damage in soybean samples and it suggests the possibility to obtain rapid information on the quality of the industrial processes.

  • Evolution of protein bound Maillard reaction end-Products and free Amadori compounds in low lactose milk in presence of fructosamine oxidase i
    Food Chemistry, 2016
    Co-Authors: Antonio Dario Troise, Martina Buonanno, Alberto Fiore, Simona Maria Monti, Vincenzo Fogliano
    Abstract:

    Thermal treatments and storage influence milk quality, particularly in low lactose milk as the higher concentration of reducing sugars can lead to the increased formation of the Maillard reaction Products (MRPs). The control of the Amadori Products (APs) formation is the key step to mitigate the Maillard reaction (MR) in milk. The use of fructosamine oxidases, (Faox) provided promising results. In this paper, the effects of Faox I were evaluated by monitoring the concentration of free and bound MRPs in low lactose milk during shelf life. Results showed that the enzyme reduced the formation of protein-bound MRPs down to 79% after six days at 37 °C. Faox I lowered the glycation of almost all the free amino acids resulting effective on basic and polar amino acids. Data here reported corroborate previous findings on the potentiality of Faox enzymes in controlling the early stage of the MR in foods.

  • Amadori Products formation in emulsified systems.
    Food Chemistry, 2016
    Co-Authors: Antonio Dario Troise, Claire C. Berton-carabin, Vincenzo Fogliano
    Abstract:

    The formation of Amadori Products (APs) is the key step determining the development of the Maillard reaction (MR). The information on the chemical behaviour of the reaction between amino acids and reducing sugars in emulsions during thermal treatments is scanty and mainly focused on volatile compounds. The aim of this work was to investigate the formation of APs from glucose and two amino acids with different partition coefficients (phenylalanine and leucine) in emulsions. Two submicron oil-in-water (O/W) emulsions consisting of water, tricaprylin and Tween 20 were prepared, thermally treated and the formation of fructose-phenylalanine (Fru-Phe) and fructose-leucine (Fru-Leu) was monitored by mass spectrometry. The concentration of Fru-Phe in submicron emulsions was similar to that in water, while Fru-Leu was reduced up to 47% in the emulsions. These data indicated that partition coefficient of amino acids, determining the reactants location, can substantially influence the MR and the final quality of foods.

  • Simultaneous quantification of amino acids and Amadori Products in foods through ion-pairing liquid chromatography–high-resolution mass spectrometry
    Amino Acids, 2015
    Co-Authors: Antonio Dario Troise, Giovanni Roviello, Alberto Fiore, Simona Maria Monti, Vincenzo Fogliano
    Abstract:

    The formation of the Amadori Products (APs) is the first key step of Maillard reaction. Only few papers have dealt with simultaneous quantitation of amino acids and corresponding APs (1-amino-1-deoxy-2-ketose). Chromatographic separation of APs is affected by several drawbacks mainly related to their poor retention in conventional reversed phase separation. In this paper, a method for the simultaneous quantification of amino acids and their respective APs was developed combining high-resolution mass spectrometry with ion-pairing liquid chromatography. The limit of detection was 0.1 ng/mL for tryptophan, valine and arginine, while the limit of quantification ranged from 2 to 5 ng/mL according to the specific sensitivity of each analyte. The relative standard deviation % was lower than 10 % and the coefficient of correlation was higher than 0.99 for each calibration curve. The method was applied to milk, milk-based Products, raw and processed tomato. Among the analyzed Products, the most abundant amino acid was glutamic acid (16,646.89 ± 1,385.40 µg/g) and the most abundant AP was fructosyl-arginine in tomato puree (774.82 ± 10.01 µg/g). The easiness of sample preparation coupled to the analytical performances of the proposed method introduced the possibility to use the pattern of free amino acids and corresponding APs in the evaluation of the quality of raw food as well as the extent of thermal treatments in different food Products.

  • Simultaneous quantification of amino acids and Amadori Products in foods through ion-pairing liquid chromatography-high-resolution mass spectrometry.
    Amino Acids, 2014
    Co-Authors: Antonio Dario Troise, Giovanni Roviello, Alberto Fiore, Simona Maria Monti, Vincenzo Fogliano
    Abstract:

    The formation of the Amadori Products (APs) is the first key step of Maillard reaction. Only few papers have dealt with simultaneous quantitation of amino acids and corresponding APs (1-amino-1-deoxy-2-ketose). Chromatographic separation of APs is affected by several drawbacks mainly related to their poor retention in conventional reversed phase separation. In this paper, a method for the simultaneous quantification of amino acids and their respective APs was developed combining high-resolution mass spectrometry with ion-pairing liquid chromatography. The limit of detection was 0.1 ng/mL for tryptophan, valine and arginine, while the limit of quantification ranged from 2 to 5 ng/mL according to the specific sensitivity of each analyte. The relative standard deviation % was lower than 10 % and the coefficient of correlation was higher than 0.99 for each calibration curve. The method was applied to milk, milk-based Products, raw and processed tomato. Among the analyzed Products, the most abundant amino acid was glutamic acid (16,646.89 ± 1,385.40 µg/g) and the most abundant AP was fructosyl-arginine in tomato puree (774.82 ± 10.01 µg/g). The easiness of sample preparation coupled to the analytical performances of the proposed method introduced the possibility to use the pattern of free amino acids and corresponding APs in the evaluation of the quality of raw food as well as the extent of thermal treatments in different food Products.

Antonio Dario Troise - One of the best experts on this subject based on the ideXlab platform.

  • the quantification of free Amadori compounds and amino acids allows to model the bound maillard reaction Products formation in soybean Products
    Food Chemistry, 2018
    Co-Authors: Antonio Dario Troise, Vincenzo Fogliano, Markus Wiltafsky, Paola Vitaglione
    Abstract:

    The quantification of protein bound Maillard reaction Products (MRPs) is still a challenge in food chemistry. Protein hydrolysis is the bottleneck step: it is time consuming and the protein degradation is not always complete. In this study, the quantitation of free amino acids and Amadori Products (APs) was compared to the percentage of blocked lysine by using chemometric tools. Eighty thermally treated soybean samples were analyzed by mass spectrometry to measure the concentration of free amino acids, free APs and the protein-bound markers of the Maillard reaction (furosine, Ne-(carboxymethyl)-l-lysine, Ne-(carboxyethyl)-l-lysine, total lysine). Results demonstrated that Discriminant Analysis (DA) and Correlated Component Regression (CCR) correctly estimated the percent of blocked lysine in a validation and prediction set. These findings indicate that the measure of free markers reflects the extent of protein damage in soybean samples and it suggests the possibility to obtain rapid information on the quality of the industrial processes.

  • Encapsulation of ascorbic acid promotes the reduction of Maillard reaction Products in UHT milk
    Food & Function, 2016
    Co-Authors: Antonio Dario Troise, Daniele Vitiello, Catherine Tsang, Alberto Fiore
    Abstract:

    The presence of amino groups and carbonyls renders fortified milk with ascorbic acid particularly susceptible to the reduction of available lysine and to the formation of Maillard reaction Products (MRPs), as Ne-(carboxyethyl)-L-lysine (CEL), Ne-(carboxymethyl)-L-lysine (CML), Amadori Products (APs) and off-flavors. A novel approach was proposed to control the Maillard reaction (MR) in fortified milk: ascorbic acid was encapsulated in a lipid coating and the effects were tested after a lab scale UHT treatment. Encapsulation promoted a delayed release of ascorbic acid and a reduction in the formation of MRPs. Total lysine increased up to 45% in milk with encapsulated ascorbic acid, while reductions in CML, CEL and furosine ranged from 10% to 53% compared with control samples. The effects were also investigated towards the formation of amide-AGEs (advanced glycation end Products) by high resolution mass spectrometry (HRMS) revealing that several mechanisms coincide with the MR in the presence of ascorbic acid.

  • Evolution of protein bound Maillard reaction end-Products and free Amadori compounds in low lactose milk in presence of fructosamine oxidase i
    Food Chemistry, 2016
    Co-Authors: Antonio Dario Troise, Martina Buonanno, Alberto Fiore, Simona Maria Monti, Vincenzo Fogliano
    Abstract:

    Thermal treatments and storage influence milk quality, particularly in low lactose milk as the higher concentration of reducing sugars can lead to the increased formation of the Maillard reaction Products (MRPs). The control of the Amadori Products (APs) formation is the key step to mitigate the Maillard reaction (MR) in milk. The use of fructosamine oxidases, (Faox) provided promising results. In this paper, the effects of Faox I were evaluated by monitoring the concentration of free and bound MRPs in low lactose milk during shelf life. Results showed that the enzyme reduced the formation of protein-bound MRPs down to 79% after six days at 37 °C. Faox I lowered the glycation of almost all the free amino acids resulting effective on basic and polar amino acids. Data here reported corroborate previous findings on the potentiality of Faox enzymes in controlling the early stage of the MR in foods.

  • Amadori Products formation in emulsified systems.
    Food Chemistry, 2016
    Co-Authors: Antonio Dario Troise, Claire C. Berton-carabin, Vincenzo Fogliano
    Abstract:

    The formation of Amadori Products (APs) is the key step determining the development of the Maillard reaction (MR). The information on the chemical behaviour of the reaction between amino acids and reducing sugars in emulsions during thermal treatments is scanty and mainly focused on volatile compounds. The aim of this work was to investigate the formation of APs from glucose and two amino acids with different partition coefficients (phenylalanine and leucine) in emulsions. Two submicron oil-in-water (O/W) emulsions consisting of water, tricaprylin and Tween 20 were prepared, thermally treated and the formation of fructose-phenylalanine (Fru-Phe) and fructose-leucine (Fru-Leu) was monitored by mass spectrometry. The concentration of Fru-Phe in submicron emulsions was similar to that in water, while Fru-Leu was reduced up to 47% in the emulsions. These data indicated that partition coefficient of amino acids, determining the reactants location, can substantially influence the MR and the final quality of foods.

  • Simultaneous quantification of amino acids and Amadori Products in foods through ion-pairing liquid chromatography–high-resolution mass spectrometry
    Amino Acids, 2015
    Co-Authors: Antonio Dario Troise, Giovanni Roviello, Alberto Fiore, Simona Maria Monti, Vincenzo Fogliano
    Abstract:

    The formation of the Amadori Products (APs) is the first key step of Maillard reaction. Only few papers have dealt with simultaneous quantitation of amino acids and corresponding APs (1-amino-1-deoxy-2-ketose). Chromatographic separation of APs is affected by several drawbacks mainly related to their poor retention in conventional reversed phase separation. In this paper, a method for the simultaneous quantification of amino acids and their respective APs was developed combining high-resolution mass spectrometry with ion-pairing liquid chromatography. The limit of detection was 0.1 ng/mL for tryptophan, valine and arginine, while the limit of quantification ranged from 2 to 5 ng/mL according to the specific sensitivity of each analyte. The relative standard deviation % was lower than 10 % and the coefficient of correlation was higher than 0.99 for each calibration curve. The method was applied to milk, milk-based Products, raw and processed tomato. Among the analyzed Products, the most abundant amino acid was glutamic acid (16,646.89 ± 1,385.40 µg/g) and the most abundant AP was fructosyl-arginine in tomato puree (774.82 ± 10.01 µg/g). The easiness of sample preparation coupled to the analytical performances of the proposed method introduced the possibility to use the pattern of free amino acids and corresponding APs in the evaluation of the quality of raw food as well as the extent of thermal treatments in different food Products.

Piotr Stefanowicz - One of the best experts on this subject based on the ideXlab platform.

  • Intramolecularly stapled amphipathic peptides via a boron–sugar interaction
    Chemical Communications, 2020
    Co-Authors: Monika Kijewska, Piotr Stefanowicz, Łukasz Jaremko, Mariusz Jaremko, Mateusz Waliczek, Angelika Czerwińska, Samah Al-harthi, Grzegorz Wołczański, Abdul-hamid Emwas, Zbigniew Szewczuk
    Abstract:

    Amadori Products (deoxyfructosyllysine derivatives) that can selectively interact with phenylboronic acids and borate ions were synthesized. The intramolecular interactions between the fructosyl moiety and phenylboronic acid incorporated into various positions of the peptide chain were investigated using high-resolution mass spectrometry (HR–MS), circular dichroism (CD), and nuclear magnetic resonance (NMR).

  • Comparison of modification sites in glycated crystallin in vitro and in vivo
    2016
    Co-Authors: Martyna Kielmas, Piotr Stefanowicz, Alicja Kluczyk, Monika Kijewska, Jolanta Oficjalska, Bożena Gołębiewska, Zbigniew Szewczuk
    Abstract:

    Abstract Glycation ofα-crystallin is responsible for age- and diabetic-related cataracts, which are the main cause of blind-ness worldwide. We optimized the method of identification of lysine residues prone to glycation using the combination of LC-MS, isotopic labeling, and modified synthetic peptide standards with the glycated lysine derivative (Fmoc-Lys(i,i-Fru,Boc)-OH). The in vitro glycation of bovine lens α-crystallin was conducted by optimized method with the equi-molar mixture of [12C6]- and [ 13C6]D-glucose. The in vivo glycation was studied on human lens crystallin. The glycated protein was subjected to proteolysis and analyzed using LC-MS. The results of in vitro and in vivo glycation of α-crystallin reveal a different distribution of the modified lysine residues. More Amadori Products were detected as a result of the in vitro reaction due to forced glycation conditions. The developed method allowed us to identify the glycation sites in crystallin from eye lenses obtained from patients suffering from the cataract. We identified K166 in the A chain and K166 in the B chain of α-crystallin as major glycation sites during the in vitro reaction. We found also two in vivo glycated lysine residues: K92 in the B chain and K166 in the A chain, which are known as locations for Amadori Products. These modification sites were confirmed by the LC-MS experiment using two synthetic standards. This study demonstrates the applicability of the LC-MS methods com-bined with the isotopic labeling and synthetic peptide stan-dards for analysis of post-translational modifications in the biological material

  • Selective Detection of Carbohydrates and Their Peptide Conjugates by ESI-MS Using Synthetic Quaternary Ammonium Salt Derivatives of Phenylboronic Acids
    Journal of The American Society for Mass Spectrometry, 2014
    Co-Authors: Monika Kijewska, Piotr Stefanowicz, Alicja Kluczyk, Adam Kuc, Mateusz Waliczek, Aleksandra Man-kupisinska, Jolanta Lukasiewicz, Zbigniew Szewczuk
    Abstract:

    We present new tags based on the derivatives of phenylboronic acid and apply them for the selective detection of sugars and peptide-sugar conjugates in mass spectrometry. We investigated the binding of phenylboronic acid and its quaternary ammonium salt (QAS) derivatives to carbohydrates and peptide-derived Amadori Products by HR-MS and MS/MS experiments. The formation of complexes between sugar or sugar-peptide conjugates and synthetic tags was confirmed on the basis of the unique isotopic distribution resulting from the presence of boron atom. Moreover, incorporation of a quaternary ammonium salt dramatically improved the efficiency of ionization in mass spectrometry. It was found that the formation of a complex with phenylboronic acid stabilizes the sugar moiety in glycated peptides, resulting in simplification of the fragmentation pattern of peptide-derived Amadori Products. The obtained results suggest that derivatization of phenylboronic acid as QAS is a promising method for sensitive ESI-MS detection of carbohydrates and their conjugates formed by non-enzymatic glycation or glycosylation.

  • The isotopic exchange of oxygen as a tool for detection of the glycation sites in proteins.
    Analytical Biochemistry, 2011
    Co-Authors: Monika Kijewska, Piotr Stefanowicz, Alicja Kluczyk, Zbigniew Szewczuk
    Abstract:

    A nonenzymatic reaction of reducing sugars with the free amino group located at the N terminus of the polypeptide chain or in the lysine side chain results in glycation of proteins. The fragments of glycated proteins obtained by enzymatic hydrolysis could be considered as the biomarkers of both the aging process and diabetes mellitus. Here we propose a new method for the identification of peptide-derived Amadori Products in the enzymatic digest of glycated proteins. The Products of enzymatic hydrolysis of the model protein ubiquitin were incubated with H218O under microwave activation. We observed that at these conditions the Amadori compounds selectively exchange one oxygen atom in the hexose moiety. The characteristic isotopic pattern of Amadori Products treated with H218O allows fast and convenient identification of this group of compounds, whereas nonglycated peptides are not susceptible to isotopic exchange.

  • The efficient synthesis of isotopically labeled peptide-derived Amadori Products and their characterization
    Amino Acids, 2010
    Co-Authors: Katarzyna Kapczyńska, Piotr Stefanowicz, Łukasz Jaremko, Mariusz Jaremko, Alicja Kluczyk, Zbigniew Szewczuk
    Abstract:

    Protein glycation is often a cause of diabetes-associated complications. The isotopically labeled peptide-derived Amadori Products may serve as standards for quantitative determination of the glycated proteins. In this paper, we discussed various approaches to the synthesis of Amadori Products labeled selectively with stable isotopes 2H, 13C and 18O.

Alberto Fiore - One of the best experts on this subject based on the ideXlab platform.

  • Encapsulation of ascorbic acid promotes the reduction of Maillard reaction Products in UHT milk
    Food & Function, 2016
    Co-Authors: Antonio Dario Troise, Daniele Vitiello, Catherine Tsang, Alberto Fiore
    Abstract:

    The presence of amino groups and carbonyls renders fortified milk with ascorbic acid particularly susceptible to the reduction of available lysine and to the formation of Maillard reaction Products (MRPs), as Ne-(carboxyethyl)-L-lysine (CEL), Ne-(carboxymethyl)-L-lysine (CML), Amadori Products (APs) and off-flavors. A novel approach was proposed to control the Maillard reaction (MR) in fortified milk: ascorbic acid was encapsulated in a lipid coating and the effects were tested after a lab scale UHT treatment. Encapsulation promoted a delayed release of ascorbic acid and a reduction in the formation of MRPs. Total lysine increased up to 45% in milk with encapsulated ascorbic acid, while reductions in CML, CEL and furosine ranged from 10% to 53% compared with control samples. The effects were also investigated towards the formation of amide-AGEs (advanced glycation end Products) by high resolution mass spectrometry (HRMS) revealing that several mechanisms coincide with the MR in the presence of ascorbic acid.

  • Evolution of protein bound Maillard reaction end-Products and free Amadori compounds in low lactose milk in presence of fructosamine oxidase i
    Food Chemistry, 2016
    Co-Authors: Antonio Dario Troise, Martina Buonanno, Alberto Fiore, Simona Maria Monti, Vincenzo Fogliano
    Abstract:

    Thermal treatments and storage influence milk quality, particularly in low lactose milk as the higher concentration of reducing sugars can lead to the increased formation of the Maillard reaction Products (MRPs). The control of the Amadori Products (APs) formation is the key step to mitigate the Maillard reaction (MR) in milk. The use of fructosamine oxidases, (Faox) provided promising results. In this paper, the effects of Faox I were evaluated by monitoring the concentration of free and bound MRPs in low lactose milk during shelf life. Results showed that the enzyme reduced the formation of protein-bound MRPs down to 79% after six days at 37 °C. Faox I lowered the glycation of almost all the free amino acids resulting effective on basic and polar amino acids. Data here reported corroborate previous findings on the potentiality of Faox enzymes in controlling the early stage of the MR in foods.

  • Simultaneous quantification of amino acids and Amadori Products in foods through ion-pairing liquid chromatography–high-resolution mass spectrometry
    Amino Acids, 2015
    Co-Authors: Antonio Dario Troise, Giovanni Roviello, Alberto Fiore, Simona Maria Monti, Vincenzo Fogliano
    Abstract:

    The formation of the Amadori Products (APs) is the first key step of Maillard reaction. Only few papers have dealt with simultaneous quantitation of amino acids and corresponding APs (1-amino-1-deoxy-2-ketose). Chromatographic separation of APs is affected by several drawbacks mainly related to their poor retention in conventional reversed phase separation. In this paper, a method for the simultaneous quantification of amino acids and their respective APs was developed combining high-resolution mass spectrometry with ion-pairing liquid chromatography. The limit of detection was 0.1 ng/mL for tryptophan, valine and arginine, while the limit of quantification ranged from 2 to 5 ng/mL according to the specific sensitivity of each analyte. The relative standard deviation % was lower than 10 % and the coefficient of correlation was higher than 0.99 for each calibration curve. The method was applied to milk, milk-based Products, raw and processed tomato. Among the analyzed Products, the most abundant amino acid was glutamic acid (16,646.89 ± 1,385.40 µg/g) and the most abundant AP was fructosyl-arginine in tomato puree (774.82 ± 10.01 µg/g). The easiness of sample preparation coupled to the analytical performances of the proposed method introduced the possibility to use the pattern of free amino acids and corresponding APs in the evaluation of the quality of raw food as well as the extent of thermal treatments in different food Products.

  • Simultaneous quantification of amino acids and Amadori Products in foods through ion-pairing liquid chromatography-high-resolution mass spectrometry.
    Amino Acids, 2014
    Co-Authors: Antonio Dario Troise, Giovanni Roviello, Alberto Fiore, Simona Maria Monti, Vincenzo Fogliano
    Abstract:

    The formation of the Amadori Products (APs) is the first key step of Maillard reaction. Only few papers have dealt with simultaneous quantitation of amino acids and corresponding APs (1-amino-1-deoxy-2-ketose). Chromatographic separation of APs is affected by several drawbacks mainly related to their poor retention in conventional reversed phase separation. In this paper, a method for the simultaneous quantification of amino acids and their respective APs was developed combining high-resolution mass spectrometry with ion-pairing liquid chromatography. The limit of detection was 0.1 ng/mL for tryptophan, valine and arginine, while the limit of quantification ranged from 2 to 5 ng/mL according to the specific sensitivity of each analyte. The relative standard deviation % was lower than 10 % and the coefficient of correlation was higher than 0.99 for each calibration curve. The method was applied to milk, milk-based Products, raw and processed tomato. Among the analyzed Products, the most abundant amino acid was glutamic acid (16,646.89 ± 1,385.40 µg/g) and the most abundant AP was fructosyl-arginine in tomato puree (774.82 ± 10.01 µg/g). The easiness of sample preparation coupled to the analytical performances of the proposed method introduced the possibility to use the pattern of free amino acids and corresponding APs in the evaluation of the quality of raw food as well as the extent of thermal treatments in different food Products.

  • Effect of olive mill wastewater phenol compounds on reactive carbonyl species and maillard reaction end-Products in ultrahigh-temperature-treated milk
    Journal of Agricultural and Food Chemistry, 2014
    Co-Authors: Antonio Dario Troise, Antonio Colantuono, Smaro Kokkinidou, Alberto Fiore, Devin G. Peterson, Vincenzo Fogliano
    Abstract:

    Thermal processing and Maillard reaction (MR) affect the nutritional and sensorial qualities of milk. In this paper an olive mill wastewater phenolic powder (OMW) was tested as a functional ingredient for inhibiting MR development in ultrahigh-temperature (UHT)-treated milk. OMW was added to milk at 0.1 and 0.05% w/v before UHT treatment, and the concentration of MR Products was monitored to verify the effect of OMW phenols in controlling the MR. Results revealed that OMW is able to trap the reactive carbonyl species such as hydroxycarbonyls and dicarbonyls, which in turn led to the increase of Maillard-derived off-flavor development. The effect of OMW on the formation of Amadori Products and N-e-(carboxymethyl)-lysine (CML) showed that oxidative cleavage, C2–C6 cyclization, and the consequent reactive carbonyl species formation were also inhibited by OMW. Data indicated that OMW is a functional ingredient able to control the MR and to improve the nutritional and sensorial attributes of milk.