The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Tomasz Haertlé - One of the best experts on this subject based on the ideXlab platform.
-
How to increase β-Lactoglobulin susceptibility to peptic hydrolysis
Journal of Food Biochemistry, 1996Co-Authors: Jean-marc Chobert, Eric Dufour, Loïc Briand, R. Dib, Michèle Dalgalarrondo, Tomasz HaertléAbstract:Since β-Lactoglobulin is resistant to peptic hydrolysis in physiological conditions, the increase of its digestibility by this enzyme was sought by the destabilization of its folding using methods that do not influence the biological value of protein, such as high pressure, medium polarity changes (alcohol addition), and esterification (ethylation). For example, the rate of hydrolysis of β-Lactoglobulin by pepsin (negligible at 0.1 MPa) increased considerably with pressure up to 300 MPa. The susceptibility of all potential β-Lactoglobulin proteolytic sites to peptic cleavage remained constant over the pressure range that was studied. The addition of alcohols decreases the bulk dielectric constant of the medium and, according to CD measurements, increases significantly the proportion of helical structure in β-Lactoglobulin while increasing susceptibility to peptic hydrolysis. In the presence of alcohols (ethanol, ethylene glycol), β-Lactoglobulin hydrolysis by pepsin was initiated when its secondary structure began to change and diversified peptic peptide populations were obtained. The chemical modification of β-Lactoglobulin by mild esterification yields a 40%-ethylated β-Lactoglobulin derivative that is rapidly hydrolyzed by pepsin. As compared with peptic hydrolysis of β-Lactoglobulin in aqueous ethanol, 22 new sites of pepsin cleavage were induced by esterification of the protein.
-
Impact of esterification on the folding and the susceptibility to peptic proteolysis of β-Lactoglobulin
Biochimica et biophysica acta, 1995Co-Authors: Jean-marc Chobert, Loïc Briand, Valery Grinberg, Tomasz HaertléAbstract:Abstract β-Lactoglobulin was esterified and the differences between unmodified and ethylated β-Lactoglobulin were studied by microcalorimetry, circular dichroism and limited proteolysis. Microcalorimetric studies and circular dichroic spectra in aromatic regions revealed changes of esterified β-Lactoglobulin tertiary structure compared with native β-Lactoglobulin conformation in aqueous media. These changes are characteristic of molten globule state. While β-Lactoglobulin is resistant to peptic hydrolysis in aqueous and physiological conditions, a study of peptic action on esterified (ethylated, … 40% of the carboxyl groups substituted) β-Lactoglobulin in aqueous conditions showed that it is hydrolysed rapidly by this enzyme. The main part of the obtained peptic peptides has been purified and identified. Their analysis shows that 22 new sites of pepsin cleavage are induced by esterification of β-Lactoglobulin. Fourteen cleavage sites are pepsin specific and their unveiling is due to imposed tertiary structure changes. Eight of the observed new cleavage targets are entirely atypical containing either one or two distal dicarboxylic acid moieties. Apparently, the ethylation of β- and/or γ-carboxylates removing charges and grafting hydrophobic ethyl groups adapts substituted dicarboxylic amino-acid side chains for the recognition by pepsin.
-
Hydrolysis of β‐Lactoglobulin by thermolysin and pepsin under high hydrostatic pressure
Biopolymers, 1995Co-Authors: Eric Dufour, Guy Herve, Tomasz HaertléAbstract:Hydrolysis of β-Lactoglobulin with thermolysin and pepsin at pressures ranging between 0.1 and 350 MPa showed a significant increase of cleavage rates. Pressure-induced changes of susceptibility to hydrolysis of β-Lactoglobulin proteolytic sites were also observed. The pressure, raised to 200 MPa, accelerates the hydrolysis of β-Lactoglobulin by thermolysin and changes obtained peptide profiles. Initially, higher pressure makes the N-terminal, and to a smaller extent, C-terminal peptide fragments of β-Lactoglobulin molecule, more susceptible to removal by thermolysin. This indicates combined influence of pressure-induced thermolysin activation and partial unfolding of β-Lactoglobulin by compression at neutral pHs. The rates of hydrolysis of β-Lactoglobulin by pepsin (negligible at 0.1 MPa) are increased considerably with pressure up to 300 MPa. The Susceptibility of β-Lactoglobulin proteolytic sites to peptic cleavage remains constant over all the studied pressure range. The lack of significant qualitative changes in the peptic peptide profiles produced at different pressures and at clearly pressure-dependent rates points to negative reaction volume changes as the major factor in peptic hydrolysis of β-Lactoglobulin under high pressure. Thus the β-Lactoglobulin molecule resists pressure-induced unfolding in acid pHs and yields to it in neutral pHs. © 1995 John Wiley & Sons, Inc.
-
Proteolysis of β-Lactoglobulin and β-casein by pepsin in ethanolic media
International Dairy Journal, 1995Co-Authors: Michèle Dalgalarrondo, Eric Dufour, Jean-marc Chobert, Catherine Bertrand-harb, Tomasz HaertléAbstract:Abstract Limited proteolysis of β-Lactoglobulin and β-casein by pepsin was performed in the presence of varying concentrations of ethanol. β-Lactoglobulin started to be cleaved by pepsin only in ethanol concentrations greater than 20%, when its secondary structure began to change. In 25% ethanol, the rate of hydrolysis of β-Lactoglobulin was slow (40% remained intact after 40 h of hydrolysis) and many short and hydrophilic peptides were observed. The rate of hydrolysis of β-Lactoglobulin reached its maximum in 30 and 35% ethanol (80% of β-Lactoglobulin was hydrolysed after 10 h), and a mixed population of hydrophilic and hydrophobic peptides of different lengths was observed. Large hydrophobic peptides appeared first, then some shorter products. The rate of hydrolysis of β-Lactoglobulin decreased at ethanol concentrations equal to or higher than 40%, when only a few long, hydrophobic peptides were produced. As seen by circular dichroism, the addition of ethanol to β-casein induced α-helix formation and reduced the rate of casein hydrolysis without changing the peptide profile. The only exception was the yield of a single peptide (Pro81 − Met93).
-
High-pressure effects on β-Lactoglobulin interactions with ligands studied by fluorescence
Biochimica et biophysica acta, 1994Co-Authors: Eric Dufour, Gaston Hui Bon Hoa, Tomasz HaertléAbstract:The effects of pressure (0.1 MPa to 400 MPa) on intrinsic fluorescence of β-Lactoglobulin and on its binding of retinol and cis-parinaric acid have been studied at neutral and acid pHs. In neutral pH, fluorescence emission spectra of β-Lactoglobulin tryptophanes are characterized by an irreversible 14 nm red-shift indicating pressure-induced folding changes. The intensity of the fluorescence of retinol in β-Lactoglobulin-retinol complex is enhanced by a pressure increase up to 150 MPa. It decreases at higher pressures and disappears altogether at 300 MPa. β-Lactoglobulin-retinol complex does not reassociate after decompression at neutral pH. At acid pH condition, the fluorescence quenching by pressure of β-Lactoglobulin tryptophans is coupled with a 2 nm spectral shift and is fully reversible demonstrating almost complete restoration of globulin folding. The evolution of retinol fiuorescence in β-Lactoglobulin-retinol complex is also entirely reversible between 0.1 MPa and 400 MPa and the complex never dissociates in the studied pressure range. β-Lactoglobulin-cis-parinaric acid complexes at neutral and acid pH values dissociate irreversibly at 200 MPa and 350 MPa, respectively.
Eric Dufour - One of the best experts on this subject based on the ideXlab platform.
-
How to increase β-Lactoglobulin susceptibility to peptic hydrolysis
Journal of Food Biochemistry, 1996Co-Authors: Jean-marc Chobert, Eric Dufour, Loïc Briand, R. Dib, Michèle Dalgalarrondo, Tomasz HaertléAbstract:Since β-Lactoglobulin is resistant to peptic hydrolysis in physiological conditions, the increase of its digestibility by this enzyme was sought by the destabilization of its folding using methods that do not influence the biological value of protein, such as high pressure, medium polarity changes (alcohol addition), and esterification (ethylation). For example, the rate of hydrolysis of β-Lactoglobulin by pepsin (negligible at 0.1 MPa) increased considerably with pressure up to 300 MPa. The susceptibility of all potential β-Lactoglobulin proteolytic sites to peptic cleavage remained constant over the pressure range that was studied. The addition of alcohols decreases the bulk dielectric constant of the medium and, according to CD measurements, increases significantly the proportion of helical structure in β-Lactoglobulin while increasing susceptibility to peptic hydrolysis. In the presence of alcohols (ethanol, ethylene glycol), β-Lactoglobulin hydrolysis by pepsin was initiated when its secondary structure began to change and diversified peptic peptide populations were obtained. The chemical modification of β-Lactoglobulin by mild esterification yields a 40%-ethylated β-Lactoglobulin derivative that is rapidly hydrolyzed by pepsin. As compared with peptic hydrolysis of β-Lactoglobulin in aqueous ethanol, 22 new sites of pepsin cleavage were induced by esterification of the protein.
-
hydrolysis of β Lactoglobulin by thermolysin and pepsin under high hydrostatic pressure
Biopolymers, 1995Co-Authors: Eric Dufour, Guy Herve, Thomas HaertleAbstract:Hydrolysis of β-Lactoglobulin with thermolysin and pepsin at pressures ranging between 0.1 and 350 MPa showed a significant increase of cleavage rates. Pressure-induced changes of susceptibility to hydrolysis of β-Lactoglobulin proteolytic sites were also observed. The pressure, raised to 200 MPa, accelerates the hydrolysis of β-Lactoglobulin by thermolysin and changes obtained peptide profiles. Initially, higher pressure makes the N-terminal, and to a smaller extent, C-terminal peptide fragments of β-Lactoglobulin molecule, more susceptible to removal by thermolysin. This indicates combined influence of pressure-induced thermolysin activation and partial unfolding of β-Lactoglobulin by compression at neutral pHs. The rates of hydrolysis of β-Lactoglobulin by pepsin (negligible at 0.1 MPa) are increased considerably with pressure up to 300 MPa. The Susceptibility of β-Lactoglobulin proteolytic sites to peptic cleavage remains constant over all the studied pressure range. The lack of significant qualitative changes in the peptic peptide profiles produced at different pressures and at clearly pressure-dependent rates points to negative reaction volume changes as the major factor in peptic hydrolysis of β-Lactoglobulin under high pressure. Thus the β-Lactoglobulin molecule resists pressure-induced unfolding in acid pHs and yields to it in neutral pHs. © 1995 John Wiley & Sons, Inc.
-
Hydrolysis of β‐Lactoglobulin by thermolysin and pepsin under high hydrostatic pressure
Biopolymers, 1995Co-Authors: Eric Dufour, Guy Herve, Tomasz HaertléAbstract:Hydrolysis of β-Lactoglobulin with thermolysin and pepsin at pressures ranging between 0.1 and 350 MPa showed a significant increase of cleavage rates. Pressure-induced changes of susceptibility to hydrolysis of β-Lactoglobulin proteolytic sites were also observed. The pressure, raised to 200 MPa, accelerates the hydrolysis of β-Lactoglobulin by thermolysin and changes obtained peptide profiles. Initially, higher pressure makes the N-terminal, and to a smaller extent, C-terminal peptide fragments of β-Lactoglobulin molecule, more susceptible to removal by thermolysin. This indicates combined influence of pressure-induced thermolysin activation and partial unfolding of β-Lactoglobulin by compression at neutral pHs. The rates of hydrolysis of β-Lactoglobulin by pepsin (negligible at 0.1 MPa) are increased considerably with pressure up to 300 MPa. The Susceptibility of β-Lactoglobulin proteolytic sites to peptic cleavage remains constant over all the studied pressure range. The lack of significant qualitative changes in the peptic peptide profiles produced at different pressures and at clearly pressure-dependent rates points to negative reaction volume changes as the major factor in peptic hydrolysis of β-Lactoglobulin under high pressure. Thus the β-Lactoglobulin molecule resists pressure-induced unfolding in acid pHs and yields to it in neutral pHs. © 1995 John Wiley & Sons, Inc.
-
Proteolysis of β-Lactoglobulin and β-casein by pepsin in ethanolic media
International Dairy Journal, 1995Co-Authors: Michèle Dalgalarrondo, Eric Dufour, Jean-marc Chobert, Catherine Bertrand-harb, Tomasz HaertléAbstract:Abstract Limited proteolysis of β-Lactoglobulin and β-casein by pepsin was performed in the presence of varying concentrations of ethanol. β-Lactoglobulin started to be cleaved by pepsin only in ethanol concentrations greater than 20%, when its secondary structure began to change. In 25% ethanol, the rate of hydrolysis of β-Lactoglobulin was slow (40% remained intact after 40 h of hydrolysis) and many short and hydrophilic peptides were observed. The rate of hydrolysis of β-Lactoglobulin reached its maximum in 30 and 35% ethanol (80% of β-Lactoglobulin was hydrolysed after 10 h), and a mixed population of hydrophilic and hydrophobic peptides of different lengths was observed. Large hydrophobic peptides appeared first, then some shorter products. The rate of hydrolysis of β-Lactoglobulin decreased at ethanol concentrations equal to or higher than 40%, when only a few long, hydrophobic peptides were produced. As seen by circular dichroism, the addition of ethanol to β-casein induced α-helix formation and reduced the rate of casein hydrolysis without changing the peptide profile. The only exception was the yield of a single peptide (Pro81 − Met93).
-
High-pressure effects on β-Lactoglobulin interactions with ligands studied by fluorescence
Biochimica et biophysica acta, 1994Co-Authors: Eric Dufour, Gaston Hui Bon Hoa, Tomasz HaertléAbstract:The effects of pressure (0.1 MPa to 400 MPa) on intrinsic fluorescence of β-Lactoglobulin and on its binding of retinol and cis-parinaric acid have been studied at neutral and acid pHs. In neutral pH, fluorescence emission spectra of β-Lactoglobulin tryptophanes are characterized by an irreversible 14 nm red-shift indicating pressure-induced folding changes. The intensity of the fluorescence of retinol in β-Lactoglobulin-retinol complex is enhanced by a pressure increase up to 150 MPa. It decreases at higher pressures and disappears altogether at 300 MPa. β-Lactoglobulin-retinol complex does not reassociate after decompression at neutral pH. At acid pH condition, the fluorescence quenching by pressure of β-Lactoglobulin tryptophans is coupled with a 2 nm spectral shift and is fully reversible demonstrating almost complete restoration of globulin folding. The evolution of retinol fiuorescence in β-Lactoglobulin-retinol complex is also entirely reversible between 0.1 MPa and 400 MPa and the complex never dissociates in the studied pressure range. β-Lactoglobulin-cis-parinaric acid complexes at neutral and acid pH values dissociate irreversibly at 200 MPa and 350 MPa, respectively.
Helena Cacote - One of the best experts on this subject based on the ideXlab platform.
-
detection and quantification of bovine ovine and caprine milk percentages in protected denomination of origin cheeses by reversed phase high performance liquid chromatography of beta Lactoglobulins
Journal of Chromatography A, 2003Co-Authors: Isabel M P L V O Ferreira, Helena CacoteAbstract:Abstract A method for detecting and quantifying bovine, ovine and caprine milk mixtures in milk and cheeses by means of reversed-phase high-performance liquid chromatography (RP-HPLC) of β-Lactoglobulins is described. Gradient elution was carried out with a flow rate of 0.5 ml/min and a temperature of 45 °C, using a mixture of two solvents: solvent A (0.1% TFA in water) and solvent B (0.09% TFA in 80% aqueous acetonitrile, v/v). The effluent was monitored at 215 nm. Under the conditions used different chromatographic patterns were obtained for bovine, ovine and caprine whey proteins. Each milk type presented different retention times for β-Lactoglobulin peaks. Binary mixtures of bovine and ovine or bovine and caprine raw milks containing 1, 2, 5, 10, 20, 30, 50, 75 and 95% (v/v) of bovine milk, as well as ovine and caprine milk mixtures containing 1, 2, 5, 10, 20, 30, 50, 75 and 95% (v/v) of ovine milk were used for cheese making. Cheeses were prepared and ripened, according to traditional methods. Milk mixtures, fresh and ripened cheeses were analyzed. A linear relationship was established between log 10 of β-Lactoglobulin peaks ratio (calculated as peak area values ratio) and log 10 of the relative percentage of bovine or ovine milk. The ratio between β-Lactoglobulin peaks was not affected by the degree of ripening. Thus, enabling the quantification of milk type percentage, with a detection limit of 2%. This technique allowed quantification of milk species within the concentration range of 5–95%. The method was successfully applied for authenticity evaluation and quantitative determination of ovine and caprine milk percentages of commercial protected denomination of origin (PDO) cheeses.
-
Detection and quantification of bovine, ovine and caprine milk percentages in protected denomination of origin cheeses by reversed-phase high-performance liquid chromatography of beta-Lactoglobulins.
Journal of chromatography. A, 2003Co-Authors: Isabel M P L V O Ferreira, Helena CacoteAbstract:A method for detecting and quantifying bovine, ovine and caprine milk mixtures in milk and cheeses by means of reversed-phase high-performance liquid chromatography (RP-HPLC) of beta-Lactoglobulins is described. Gradient elution was carried out with a flow rate of 0.5 ml/min and a temperature of 45 degrees C, using a mixture of two solvents: solvent A (0.1% TFA in water) and solvent B (0.09% TFA in 80% aqueous acetonitrile, v/v). The effluent was monitored at 215 nm. Under the conditions used different chromatographic patterns were obtained for bovine, ovine and caprine whey proteins. Each milk type presented different retention times for beta-Lactoglobulin peaks. Binary mixtures of bovine and ovine or bovine and caprine raw milks containing 1, 2, 5, 10, 20, 30, 50, 75 and 95% (v/v) of bovine milk, as well as ovine and caprine milk mixtures containing 1, 2, 5, 10, 20, 30, 50, 75 and 95% (v/v) of ovine milk were used for cheese making. Cheeses were prepared and ripened, according to traditional methods. Milk mixtures, fresh and ripened cheeses were analyzed. A linear relationship was established between log 10 of beta-Lactoglobulin peaks ratio (calculated as peak area values ratio) and log 10 of the relative percentage of bovine or ovine milk. The ratio between beta-Lactoglobulin peaks was not affected by the degree of ripening. Thus, enabling the quantification of milk type percentage, with a detection limit of 2%. This technique allowed quantification of milk species within the concentration range of 5-95%. The method was successfully applied for authenticity evaluation and quantitative determination of ovine and caprine milk percentages of commercial protected denomination of origin (PDO) cheeses.
Shigeru Yoshida - One of the best experts on this subject based on the ideXlab platform.
-
Isolation of lactoperoxidase, lactoferrin, α-lactalbumin, β-Lactoglobulin B and β-Lactoglobulin A from bovine rennet whey using ion exchange chromatography.
The International Journal of Biochemistry & Cell Biology, 2000Co-Authors: Shigeru YoshidaAbstract:A mild and rapid method is described for isolating various milk proteins from bovine rennet whey. beta-Lactoglobulin from bovine rennet whey was easily adsorbed on and desorbed from a weak anion exchanger, diethylaminoethyl-Toyopearl. However, alpha-lactalbumin could not be adsorbed onto the resin. alpha-Lactalbumin and beta-Lactoglobulin from rennet whey could also be adsorbed and separated using a strong anion exchanger, quaternary aminoethyl-Toyopearl. The rennet whey was passed through a strong cation exchanger, sulphopropyl-Toyopearl, to separate lactoperoxidase and lactoferrin. alpha-Lactalbumin and beta-Lactoglobulin were adsorbed onto quaternary aminoethyl-Toyopearl. alpha-Lactalbumin was eluted using a linear (0-0.15 M) concentration gradient of NaCl in 0.05 M Tris-HCl buffer (pH 8.5). Subsequently, beta-Lactoglobulin B and beta-Lactoglobulin A were eluted from the column with 0.05 M Tris-HCl (pH 6.8), using a linear (0.1-0.25 M) concentration gradient of NaCl. The yields were 1260 mg alpha-lactalbumin, 1290 mg beta-Lactoglobulin B and 2280 mg beta-Lactoglobulin A from 1 l rennet whey.
-
Isolation of lactoperoxidase, lactoferrin, alpha-lactalbumin, beta-Lactoglobulin B and beta-Lactoglobulin A from bovine rennet whey using ion exchange chromatography.
The international journal of biochemistry & cell biology, 2000Co-Authors: Shigeru YoshidaAbstract:A mild and rapid method is described for isolating various milk proteins from bovine rennet whey. beta-Lactoglobulin from bovine rennet whey was easily adsorbed on and desorbed from a weak anion exchanger, diethylaminoethyl-Toyopearl. However, alpha-lactalbumin could not be adsorbed onto the resin. alpha-Lactalbumin and beta-Lactoglobulin from rennet whey could also be adsorbed and separated using a strong anion exchanger, quaternary aminoethyl-Toyopearl. The rennet whey was passed through a strong cation exchanger, sulphopropyl-Toyopearl, to separate lactoperoxidase and lactoferrin. alpha-Lactalbumin and beta-Lactoglobulin were adsorbed onto quaternary aminoethyl-Toyopearl. alpha-Lactalbumin was eluted using a linear (0-0.15 M) concentration gradient of NaCl in 0.05 M Tris-HCl buffer (pH 8.5). Subsequently, beta-Lactoglobulin B and beta-Lactoglobulin A were eluted from the column with 0.05 M Tris-HCl (pH 6.8), using a linear (0.1-0.25 M) concentration gradient of NaCl. The yields were 1260 mg alpha-lactalbumin, 1290 mg beta-Lactoglobulin B and 2280 mg beta-Lactoglobulin A from 1 l rennet whey.
Isabel M P L V O Ferreira - One of the best experts on this subject based on the ideXlab platform.
-
detection and quantification of bovine ovine and caprine milk percentages in protected denomination of origin cheeses by reversed phase high performance liquid chromatography of beta Lactoglobulins
Journal of Chromatography A, 2003Co-Authors: Isabel M P L V O Ferreira, Helena CacoteAbstract:Abstract A method for detecting and quantifying bovine, ovine and caprine milk mixtures in milk and cheeses by means of reversed-phase high-performance liquid chromatography (RP-HPLC) of β-Lactoglobulins is described. Gradient elution was carried out with a flow rate of 0.5 ml/min and a temperature of 45 °C, using a mixture of two solvents: solvent A (0.1% TFA in water) and solvent B (0.09% TFA in 80% aqueous acetonitrile, v/v). The effluent was monitored at 215 nm. Under the conditions used different chromatographic patterns were obtained for bovine, ovine and caprine whey proteins. Each milk type presented different retention times for β-Lactoglobulin peaks. Binary mixtures of bovine and ovine or bovine and caprine raw milks containing 1, 2, 5, 10, 20, 30, 50, 75 and 95% (v/v) of bovine milk, as well as ovine and caprine milk mixtures containing 1, 2, 5, 10, 20, 30, 50, 75 and 95% (v/v) of ovine milk were used for cheese making. Cheeses were prepared and ripened, according to traditional methods. Milk mixtures, fresh and ripened cheeses were analyzed. A linear relationship was established between log 10 of β-Lactoglobulin peaks ratio (calculated as peak area values ratio) and log 10 of the relative percentage of bovine or ovine milk. The ratio between β-Lactoglobulin peaks was not affected by the degree of ripening. Thus, enabling the quantification of milk type percentage, with a detection limit of 2%. This technique allowed quantification of milk species within the concentration range of 5–95%. The method was successfully applied for authenticity evaluation and quantitative determination of ovine and caprine milk percentages of commercial protected denomination of origin (PDO) cheeses.
-
Detection and quantification of bovine, ovine and caprine milk percentages in protected denomination of origin cheeses by reversed-phase high-performance liquid chromatography of beta-Lactoglobulins.
Journal of chromatography. A, 2003Co-Authors: Isabel M P L V O Ferreira, Helena CacoteAbstract:A method for detecting and quantifying bovine, ovine and caprine milk mixtures in milk and cheeses by means of reversed-phase high-performance liquid chromatography (RP-HPLC) of beta-Lactoglobulins is described. Gradient elution was carried out with a flow rate of 0.5 ml/min and a temperature of 45 degrees C, using a mixture of two solvents: solvent A (0.1% TFA in water) and solvent B (0.09% TFA in 80% aqueous acetonitrile, v/v). The effluent was monitored at 215 nm. Under the conditions used different chromatographic patterns were obtained for bovine, ovine and caprine whey proteins. Each milk type presented different retention times for beta-Lactoglobulin peaks. Binary mixtures of bovine and ovine or bovine and caprine raw milks containing 1, 2, 5, 10, 20, 30, 50, 75 and 95% (v/v) of bovine milk, as well as ovine and caprine milk mixtures containing 1, 2, 5, 10, 20, 30, 50, 75 and 95% (v/v) of ovine milk were used for cheese making. Cheeses were prepared and ripened, according to traditional methods. Milk mixtures, fresh and ripened cheeses were analyzed. A linear relationship was established between log 10 of beta-Lactoglobulin peaks ratio (calculated as peak area values ratio) and log 10 of the relative percentage of bovine or ovine milk. The ratio between beta-Lactoglobulin peaks was not affected by the degree of ripening. Thus, enabling the quantification of milk type percentage, with a detection limit of 2%. This technique allowed quantification of milk species within the concentration range of 5-95%. The method was successfully applied for authenticity evaluation and quantitative determination of ovine and caprine milk percentages of commercial protected denomination of origin (PDO) cheeses.
