Chemical methods for the characterization of proteolysis in cheese during ripening

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Electrophoresis in alkaline urea-containing gels with direct staining by Coomassie blue G250 is widely used in this and other laboratories to monitor proteolysis in various cheese varieties.

“Electrophoresis in alkaline urea-containing gels with direct staining by Coomassie blue G250 is widely used in this and other laboratories to monitor proteolysis in various cheese varieties (fig 4).”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The majority of authors have used urea-containing buffers at alkaline pH for electrophoresis.

“Although urea-containing buffers at acid pH have been used (eg, Creamer, 1991), the majority of authors have used urea-containing buffers at alkaline pH.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

Nondenaturing buffers are not suitable for caseins.

“Nondenaturing buffers are not suitable for caseins, although they are used for the analysis of whey proteins.”

It may state two separate claims as one.

In a 10 kDa UF permeate, peptides did not stain with Coomassie blue on urea-PAGE, but the retentate of the WSE contained several detectable peptides, as did 2% TCA-soluble and insoluble fractions of the retentate.

“Q' Sullivan and Fox (1990) found that the peptides in a 10 kOa UF permeate did not stain with Coomassie blue on urea-PAGE, but the retentate of the WSE contained several detectable peptides, as did 2% TCA-soluble and insoluble fractions of the retentate.”

• cites Q' Sullivan and Fox (1990)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Low molecular mass peptides can be visualized using a silver staining technique involving extensive fixing with glutaraldehyde.

“Low molecular mass peptides can be visualized using a silver staining technique involving extensive fixing with glutaraldehyde, although such stains have not been used widely to study cheese peptides.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

IEF has been particularly valuable in studies on genetic polymorphism in milk proteins.

“It has been particularly valuable in studies on genetic polymorphism in milk proteins (see Creamer, 1991;and Strange et al, 1992, for references).”

• cites Creamer, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Strange et al, 1992Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Nearly all one-dimensional PAGE techniques used in recent studies on cheese have employed discontinuous buffer systems containing urea or SDS as a dissociating agent.

“However, nearly ail onedimensional PAGE techniques used in recent studies on chee se have employed discontinuous buffer systems containing urea or sodium dodecylsulphate (SOS) as a dissociating agent.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Electrophoresis in alkaline urea gels (pH 8.9), stained with amido black 10B and scanned by densitometry, gave good quantitative results.

“However, de Jong (1975) reported that electrophoresis in alkaline urea gels (pH 8.9), stained with ami do black lOB and scanned by densitometry, gave good quantitative results.”

• cites de Jong (1975)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Starch gels have been largely replaced by polyacrylamide gels.

“and have been largely replaced by polyacrylamide gels.”

• cites Creamer, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

Two-dimensional electrophoresis is time-consuming and there are difficulties with reproducibility and in obtaining quantitative data.

“Although 2-D electrophoresis may give good resolution, it is timeconsuming and there are difficulties with reproducibility and in obtaining quantitative data (Creamer, 1991).”

• cites Creamer, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Identification of peptides produced during cheese ripening has posed difficulties.

“Identification of peptides produced during cheese ripening has posed difficulties.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Kim and Jimenez-Flores obtained excellent resolution of milk proteins by preparative IEF followed by urea- or SDS-PAGE.

“Kim and Jimenez-Flores (1994) obtained excellent resolution of milk proteins by preparative IEF followed by urea-or SOS-PAGE.”

• cites Kim and Jimenez-Flores (1994)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Zonal electrophoresis on paper, porous cellulose acetate, or in agar or agarose gels is now rarely used.

“Zonal electrophoresis on paper (eg, Lindqvist et al, 1953;Kuchroo and Fox, 1982b), porous cellulose acetate or in agar or agarose gels are now rarely used.”

• cites Lindqvist et al, 1953Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Kuchroo and Fox, 1982bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

Starch gels are brittle and opaque after staining.

“starch gels are brittle and opaque after staining (Creamer, 1991)”

• cites Creamer, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

Paper chromatography is cheap and straightforward, but suitable only for assessing the complexity of systems containing only small peptides.

“Paper chromatography is cheap and straightforward, but suitable only for assessing the complexity of systems containing only small peptides (Ardë and Gripon, 1991) and has been large1y superseded by other techniques.”

• cites Ardë and Gripon, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds. It may state two separate claims as one.

The introduction of HPIEC and HPSEC has greatly reduced the workload involved in these forms of column chromatography, while increasing speed and reproducibility.

“has greatly reduced the workload involved in these forms of column chromatography, while increasing speed and reproducibility.”

It may state two separate claims as one.

Addeo et al used immunoblotting to detect bands in electrophoretograms of a number of cheese varieties, permitting identification of the casein from which a number of peptides originated.

“Addeo et al (1995) used immunoblotting (rabbit polyclonal antibodies raised against the caseins and peroxidase-Iabelled immunoglobulins as secondary antibodies) to detect bands in electrophoretograms of a number of cheese varieties.This technique permitted the identification of the casein from which a number of peptides originated.”

• cites Addeo et al (1995)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

No reports of capillary electrophoretograms of cheese peptides appear to have been published to date.

“The authors are aware of a number of laboratories investigating the potential of CE to study proteolysis in cheese, although no reports of capillary electrophoretograms of cheese peptides appear to have been published to date.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

In CE, the composition of running buffer can be changed easily and separation times are relatively short, although only one sample at a time can be analyzed.

“The composition of running buffer can be changed easily and separation times are relatively short, although only one sample at a time can be analyzed.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Ion-exchange chromatography is used widely to fractionate milk proteins but has only had limited use in cheese analysis.

“Ion-exchange chromatography is used widely to fractionate milk proteins but has only had limited use in cheese analysis (Fox, 1989).”

• cites Fox, 1989Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Low-pressure, preparative HPLC techniques on size-exclusion media have simplified this form of chromatography.

“Low-pressure, preparative HPLC techniques (eg, FPLCTM, Pharmacia, Uppsala, Sweden) on size-exc1usion media have simplified this form of chromatography.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The majority of the peptides in a urea-PAGE electrophoretogram of Cheddar cheese were partially identified by McSweeney et al.

“The majority of the peptides in a urea-PAGE electrophoretogram of Cheddar cheese were partially identified (fig 5) by McSweeney et al (1994a).”

• cites McSweeney et al (1994a)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

Both paper and TLC chromatographic techniques are now rarely used.

“Both paper and TLC chromatographic techniques are now rarely used.”

It may state two separate claims as one.

RP-HPLC has been used extensively to characterize peptides in casein hydrolyzates and is also very valuable for resolving shorter peptides in cheese fractions.

“Reverse phase-HPLC has been used extensively to characterize peptides in casein hydrolyzates (eg, Le Bars and Gripon, 1989;McSweeney et al, 1993b) and the technique is also very valuable for resolving shorter peptides in cheese fractions.”

• cites Le Bars and Gripon, 1989Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites McSweeney et al, 1993bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Unlike conventional electrophoresis, CE uses continuous monitoring by UV absorbance, and potentially by other detection techniques used in HPLC.

“Unlike conventional electrophoresis, in which proteins and peptides in a gel are visualized by staining, CE uses continuous monitoring by UV absorbance, and potentially by the range of other techniques used for detection in HPLC.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds. It may state two separate claims as one.

The capital cost of CE instrumentation at present is higher than that of equivalent HPLC, although costs are likely to fall.

“The capital cost of CE instrumentation at present is higher than that of equivalent high performance liquid chromatographs (HPLC), although costs are likely to fall.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

In the authors' experience, anion-exchange chromatography on DEAE-cellulose or equivalent high-performance medium in urea-containing buffers is very suitable for the fractionation of large casein-derived peptides.

“ln our experience, anion-exchange chromatography on DEAE-cellulose or equivalent high-performance medium (eg, Mono-QTM) in urea-containing buffers is very suitable for the fractionation of large casein-derived peptides.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

To date, FSCE has been the form of CE most widely used in dairy chemistry.

“To date, FSCE has been the form of CE most widely used in dairy chemistry.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

TLC is a simple, straightforward method for separating peptides and is normally superior to paper chromatography.

“TLC is a simple, straightforward method for separating peptides and is normally superior to paper chromatography, although Kuchroo and Fox (1983a) obtained better resolution of peptides by PC than by TLC.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

The most popular forms of chromatography for analysis of cheese peptides have been ion-exchange and size-exclusion techniques and reverse-phase HPLC.

“The most popular forms of chromatography for analysis of cheese peptides have been ionexchange and size-exclusion techniques and reverse-phase high performance liquid chromatography (RP-HPLC).”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Wilkinson et al resolved press juice from Cheddar by HPSEC on a Superose-12 column; changes in the peptide profile during ripening were evident.

“Wilkinson et al (1992) resolved press juice from Cheddar by high-performance size-exclusion chromatography (HPSEC) on a Superose-12 column; changes in the peptide profile during ripening were evident.”

• cites Wilkinson et al (1992)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Paper chromatography has been largely superseded by other techniques.

“and has been large1y superseded by other techniques.”

It may state two separate claims as one.

Ninhydrin reacts with ammonia almost as readily as with amino groups, and therefore levels of proteolysis found by ninhydrin assays are consistently higher than those found by the TNBS procedure, the discrepancy being due to ammonia.

“Ninhydrin reacts with ammonia almost as readily as with amino groups and therefore levels of proteolysis found by ninhydrin assays are consistently higher than those found by the TNBS procedure, the discrepancy being due to ammonia (Clegg et al, 1982).”

• cites Clegg et al, 1982Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

The Cd-ninhydrin reagent is more selective for the amino group of free amino acids than for the amino groups of peptides or proteins and is the most sensitive of several ninhydrin reagents, including Sn-ninhydrin.

“The Cd-ninhydrin reagent was found to he more selective for the amino group of free amino acids th an for the amino groups of peptides or proteins and was the most sensitive of several ninhydrin reagents, inc1uding Sn-ninhydrin.”

• cites Doi et al (1981) sourceNot checked — no full text of the source

It may state two separate claims as one.

The purple chromophore Ruhemann's purple does not remain attached to the protein or peptide and therefore is not precipitated during clarification procedures prior to spectrophotometric analysis at 570 nm, which is a major advantage of the ninhydrin technique.

“The purple chromophore, named Ruhemann' s purple after its discoverer, does not remain attached to the protein or peptide and therefore is not precipitated during procedures necessary to c1arify the sam-pIe prior to spectrophotometric analysis at 570 nm (Ardë and Meisel, 1991), which is a major advantage of the technique (Pearce et al, 1988).”

• cites Ardë and Meisel, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Pearce et al, 1988Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

The Cd-ninhydrin assay can be performed on citrate-, water- or PTA-soluble fractions but not on TCA-soluble fractions, as the latter interfere with colour development.

“could be performed on citrate-, water-or PT A-soluble fractions but not on TCA-soluble fractions, as the latter appeared to interfere with colour development.”

• cites Folkertsma and Fox (1992)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

A linear relationship exists between the concentration of α-amino groups and A420 in the TNBS procedure for assessing degree of hydrolysis of food proteins, but the relationship varies between proteins owing to variations in lysine concentration.

“a linear relationship was found between the concentration of œ-amino groups and A 420 but the relationship varied between proteins owing to variations in the concentration of lysine.”

• cites Alder-Nissen (1979)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The method of Habeeb (1966) forms an unstable coloured complex and is liable to operator error.

“Barlow et al (1986) reported that the latter is preferable to the method of Habeeb (1966) in which an unstable coloured complex is formed and the procedure is liable to operator error.”

• cites Barlow et al, 1986Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

L-Amino acid oxidase is not equally active on all amino acids; it exhibits high activity on Leu, Phe and Trp, but His, Ile and Cys are poor substrates.

“However, this enzyme is not equally active on ail amino acids; it exhibits high activity on Leu, Phe and Trp but His, Ile and Cys are poor substrates (Puchades et al, 1990).”

• cites Puchades et al, 1990Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The OPA method is more accurate than measurement of A280 and more convenient than the ninhydrin, TNBS or fluorescamine procedures for quantifying proteolysis in milk protein systems.

“Church et al (1983), who used OPA to quantify proteolysis in milk protein systems, reported that the method is more accurate than the measurement of A 280 and is more convenient than the ninhydrin, TNBS or fluorescamine procedures.”

• cites Church et al (1983)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The OPA method is fast and simple for estimating free amino acids in cheese and, if reaction time is strictly controlled, is less variable than the TNBS method.

“Lemieux et al (1990) considered the OPA method to be fast and simple for estimating free amino acids in cheese and if the reaction time was strictly controlled, was less variable than the TNBS method”

• cites Lemieux et al (1990)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

Cd-ninhydrin reactive amino groups form in Cheddar cheese and in an Irish artisanal blue cheese during ripening.

“Formation of Cd-ninhydrin reactive amino groups in Cheddar (.) and an Irish artisanal blue cheese (e) during ripening.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The water-insoluble fraction of 3-month-old Cheddar cheese made with Lactococcus lactis subsp lactis SK11 contains polypeptides whose N-termini were identified by McSweeney et al (1994).

“Urea-polyacrylamide gel electrophoretograms of casein (eN) and the water-insoluble fraction (WISF) of 3-month-old Cheddar cheese made with Lactococeus lactis subsp lactis SKII, indicating the positions of the caseins and the N-terminii of the polypeptides identified by McSweeney et al (1994)”

• cites McSweeney et al (1994) sourceNot checked — no full text of the source

It may state two separate claims as one.

The free Glu content of Cheddar cheeses increased with age and varied between cheeses with different non-starter populations.

“The free Glu content of the chee ses increased with age and varied between cheeses with different non-starter populations.”

• cites McSweeney et al (1993a)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

A dye-binding method could be used as an index of proteolysis in cheese.

“Kroger and Weaver (1979) reported that a dye-binding method could be used as an index of proteolysis in cheese”

• cites Kroger and Weaver (1979)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Fluorescamine gave more consistent results than TNBS for quantifying acid-soluble proteins, peptides and amino acids in cheese extracts.

“These authors c1aimed that this reagent gave more consistent results than TNBS.”

• cites Creamer et al, 1985Not checked — no full text of the source

It may state two separate claims as one.

WSN as a percentage of total N varies with cheese variety and increases throughout ripening; a typical value for mature Cheddar cheese is about 25%.

“WSN as a percentage of total N varies with variety and increases throughout ripening (fig 1); a typical value for mature Cheddar cheese is -25%.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

A decrease in the dye-binding capacity of a dispersion of Cheddar cheese with age was demonstrated.

“A decrease in the dye-binding capacity of a dispersion of Cheddar cheese with age was dernonstrated by Ashworth (1966).”

• cites Ashworth (1966)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

The water-soluble extract (WSE) of Cheddar cheese contains numerous small- and medium-sized peptides, free amino acids and their degradation products, organic acids and their salts; extraction with water efficiently separates the small peptides in cheese from proteins and large peptides.

“The water-soluble extract (WSE) of Cheddar cheese contains numerous small-and medium-sized peptides, free amino acids and their degradation products, organic acids and their salts; extraction with water efficiently separates the small peptides in cheese from proteins and large peptides.”

It may state two separate claims as one.

The principal peptides in the water-insoluble fraction of Cheddar cheese are produced from αs1-casein by chymosin or pepsin or from β-casein by plasmin, and therefore the complementary primary water-soluble peptides must be produced via the action of these enzymes.

“Water-insoluble peptides in Cheddar chee se have been studied by McSweeney et al (I994a), who found that the principal peptides in this fraction were produced from u.sl-casein by chymosin or pepsin or from ~-casein by plasmin and therefore that the complementary primary water-soluble peptides must be produced via the action of these enzymes.”

• cites McSweeney et al (I994a)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

The enzymatic assay for total free amino acids using L-amino acid oxidase is rapid, reproducible and specific for free amino acids, since peptides are not degraded by L-amino acid oxidase.

“This technique was reported to be rapid and reproducible and specifie for free amino acids, since peptides, which react to a greater or lesser extent in most other direct-assay procedures for free amino acids, are not degraded by L-amino acid oxidase.”

• cites Puchades et al, 1990Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

Trichloroacetic acid (12%) and 70% ethanol yield approximately equal extraction levels and soluble fractions contain similar peptides, although differences are apparent in the peptides in the insoluble fractions.

“Trichloroacetic acid, TCA (12%, see below) and 70% ethanol yield approximately equal extraction levels (Reville and Fox, 1978) and soluble fractions contain similar peptides (Kuchroo and Fox, 1982b), although differences are apparent in the peptides in the insoluble fractions.”

• cites Reville and Fox, 1978Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Kuchroo and Fox, 1982bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The dye-binding method of McGann et al (1972), using amido black, is not suitable for use as an index of proteolysis in cheese.

“Kuchroo et al (1983) concluded that the dye-binding method of McGann et al (1972), using amido black, is not suitable for this purpose.”

• cites Kuchroo et al (1983)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites McGann et al (1972)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Only 40% of the water-soluble N was soluble in 0.1 mol/L CaCl2.

“Kuchroo and Fox (1982a) found that only 40% of the WSN was soluble in 0.1 mol/L CaCI 2 .”

• cites Kuchroo and Fox (1982a)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

The increase in CaCl2-soluble N correlates with the age of cheese and the extracts contain whey proteins, peptides and amino acids, while the CaCl2-insoluble fraction contains caseins and large peptides, similar to those in the water-insoluble fraction.

“The increase in CaClrsoluble N correlates with the age of cheese and the ex tracts contain whey proteins, peptides and amino acids, while the CaCl r insoluble fraction con tains caseins and large peptides, similar to those in the water-insoluble fraction (Christensen et al, 1991).”

• cites Christensen et al, 1991Not checked — no full text of the source

It may state two separate claims as one.

NaCl (5%)-soluble N and unfractionated cheese are indistinguishable electrophoretically, indicating that the parent caseins, as well as peptides, are extracted.

“NaCI (5% )-soluble N and unfractionated cheese are indistinguishable electrophoretically, indicating that the parent caseins, as weil as peptides, are extracted (Rank et al, 1985;Bican and Spahni, 199 J),”

• cites Rank et al, 1985Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Bican and Spahni, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

There is no precipitation threshold relating peptide size to solubility in TCA, but all peptides studied by Yvon et al (1989) containing less than seven amino acid residues were soluble in 12% TCA; peptide solubility is related to hydrophobicity.

“There is no 'precipitation threshold' relating peptide size to solubility in TCA, but ail peptides studied by Yvon et al (1989) containing less than seven amino acid residues were soluble in 12% TCA; peptide solubility is related to hydrophobicity.”

• cites Yvon et al (1989)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

More than 90% of Cheddar cheese N was soluble in 5% NaCl, which was thus not sufficiently discriminating, except perhaps for very young cheeses.

“Reville and Fox (1978) claimed that> 90% of Cheddar cheese N was soluble in 5% NaCl, which was thus not sufficiently discriminating, ex ce pt perhaps for very young cheeses.”

• cites Reville and Fox (1978)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds. It may state two separate claims as one.

Whey proteins and proteose peptones from plasmin action are also soluble at pH 4.6, but their contribution to pH 4.6-soluble N is relatively small.

“Whey proteins and proteose peptones (from plasmin action) are also soluble at pH 4.6, but their contribution to pH 4.6-SN is relatively srnall;”

It may state two separate claims as one.

Chloroform/methanol extracts more N than water, but chromatograms of both extracts on Sephadex G-25 were similar.

“Chloroform/methanol extracts more N than water, which is understandable considering the relatively hydrophobie nature of many caseinderived peptides, but chromatograms of both extracts on Sephadex G-25 were similar (Rank et al, 1985).”

• cites Rank et al, 1985Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

pH 4.6-soluble N is produced mainly by rennet and increases during ripening.

“Like WSN, pH 4.6-SN is produced mainly by rennet (O' Keeffe et al, 1976) and increases during ripening (eg, fig 1).”

• cites O' Keeffe et al, 1976Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The level of 12% TCA-soluble N is a better index of maturity than water-soluble N.

“Venema et al (1987) reported that the level of 12% TCA-soluble N is a better index of maturity than WSN.”

• cites Venema et al (1987)Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

RP-HPLC does not adequately resolve larger casein-derived peptides.

“In our experience, RP-HPLC does not adequately resolve larger casein-derived peptides.”

It may state two separate claims as one.

Typically, in a mature Cheddar about 15% of the total N and about 90% of the water-soluble N is soluble in 2.5% TCA; while 50-60% of a UF retentate (10 kDa membranes) and 100% of the UF permeate is soluble in 2% TCA.

“Typically, in a mature Cheddar about 15% of the total N (Reville and Fox, 1978) and -90% of the WSN (Kuchroo and Fox, 1982b) is soluble in 2.5% TCA; while 50-60% of a UF retentate (10 kDa membranes) and 100% of the UF permeate (0' Sullivan and Fox, 1990) is soluble in 2% TCA.”

• cites Reville and Fox, 1978Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Kuchroo and Fox, 1982bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites O'Sullivan and Fox, 1990Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

Rennet is responsible for the production of some of the 12% TCA-soluble N, but starter proteinases and peptidases make a substantial contribution to the formation of 12% TCA-soluble N.

“Rennet is responsible for the production of sorne of the 12% TCA-soluble N, but starter proteinases and peptidases make a substantial contribution (Reiter et al, 1969;0' Keeffe et al, 1976) to the formation of 12% TCA-soluble N.”

• cites Reiter et al, 1969Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites O' Keeffe et al, 1976Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

More than 200 peptides have been isolated and identified from the water-soluble extract of Cheddar.

“For ex ample, > 200 peptides have been isolated and identified from the WSE of Cheddar (Singh et al, 1994(Singh et al, , 1995(Singh et al, , 1996)).”

• cites Singh et al, 1994 sourceNot checked — no full text of the source
• cites Singh et al, 1995Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Singh et al, 1996Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The method based on Peterson et al has been used in the authors' laboratory to prepare phosphopeptides from Cheddar.

“This method, based on that of Peterson et al (1957), has been used in the authors' laboratory to prepare phosphopeptides from Cheddar.”

• cites Peterson et al, 1957Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

Preliminary results from this laboratory suggest that the Bradford method and erythrosin are unsuitable for analysis of cheese fractions.

“Protein can also be estimated by the Bradford method (which is based on a colour change in Coomassie blue on binding to protein) or by using erythrosin, but preliminary results from this laboratory suggest that these methods are unsuitable for analysis of chee se fractions.”

It may state two separate claims as one.

Electroblotting is preferable to excision of bands for isolating peptides from PAGE gels because of higher recoveries of protein and because the size of PAGE gels can change on staining, making accurate excision of unstained regions difficult.

“The latter technique is preferable because of higher recoveries of protein and because the size of PAGE gels can change on staining which makes accurate excision of unstained regions difficult.”

It may state two separate claims as one.

The Coomassie blue staining procedure is limited to detection of primary degradation products in cheese because only relatively large peptides stain under these conditions.

“However, since only relatively large peptides stain under these conditions, the procedure is limited to the detection of the primary degradation products in cheese.”

• AssumptionRests on an assumption: Only proteins and large peptides can be visualized by staining.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Band dimensions are critical for densitometry, and dye uptake is a function of the protein as well as staining and destaining protocol.

“He emphasized that band dimensions are critical for densitometry, and that dye uptake is a function of the protein as weil as staining and destaining protocol.”

• cites Creamer, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

CE has a number of advantages over traditional electrophoretic techniques, including the choice of running buffer and the use of automated, high-performance instrumentation.

“It has a number of advantages over traditional electrophoretic techniques, including the choice of running buffer and the use of automated, high-performance instrumentation.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

It is unlikely that CE will replace chromatographic and other electrophoretic methods, and it is now viewed as complementing other separation techniques.

“It is unlikely that CE will replace chromatographie and other electrophoretic methods, and it is now viewed as complementing other separation techniques (Lindeberg, 1996a).”

• cites Lindeberg, 1996aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

For fractions containing smaller peptides, absorbance at 220 nm is preferable to 280 nm, since small peptides may not contain aromatic residues.

“Generally, 280 nm is used but for fractions containing smaller peptides, absorbance of the carbonyl group in the peptide bond at a lower wavelength, eg, 220 nm (Foster and Green, 1974;Green and Foster, 1974) is preferable, since small peptides may not contain aromatic residues.”

• cites Foster and Green, 1974Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Green and Foster, 1974 sourceNot checked — no full text of the source

• AssumptionRests on an assumption: Small peptides may not contain aromatic residues.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Electroblotted peptides can be identified by N-terminal amino acid sequencing, but they are more difficult to analyze by mass spectrometry because they cannot be stained prior to MS and must be eluted from the blotting matrix.

“Electroblotted peptides can be identified by N-terminai amino acid sequencing (see below), but they are more difficult to analyze by mass spectrometry (MS) because they cannot be stained prior to MS and must he eluted from the blotting matrix.”

It may state two separate claims as one.

HPSEC on a Superose-12 column is valuable for characterizing peptides in various fractions from Cheddar and is suitable for preparing peptide fractions.

“HPSEC on a Superose-12 column is also valuable for characterizing peptides in various fractions from Cheddar (Breen et al, 1995) and is suitable for preparing peptide fractions.”

• cites Breen et al, 1995Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Molecular weights may be estimated by size-exclusion chromatography on a calibrated column.

“Molecular weights may be estimated by sizeexclusion chromatography on a calibrated column.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

CE separates peptides on the basis of net charge, mass, and Stokes' radius, and sometimes on some other property of the peptide.

“CE separates on the basis of the net charge on the peptides, their mass and Stokes' radius (Young et al, 1992) and sometimes on sorne other property of the peptide (see below).”

• cites Young et al, 1992Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds. It may state two separate claims as one.

Sample size in CE is extremely small and therefore the technique is not suitable for preparative-scale work.

“Sample size in CE is extremely small and therefore the technique is not suitable for preparative-scale work.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The dry TNBS powder is explosive, and prolonged storage leads to high blank values.

“A disadvantage of the TNBS method is that the dry powder is explosive, and prolonged storage leads to high blank values (Ardô and Meisel, 1991).”

• cites Ardô and Meisel, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Fluorimetric reagents for quantifying free amino groups are more sensitive than the colorimetric methods described but have not been used as widely.

“Such techniques are more sensitive than the colorimetrie methods described above but have not been used as widely.”

It may state two separate claims as one.

Difficulties remain with the interpretation of RP-HPLC data and the development of a solvent system which will permit tasting of the fractions.

“Difficulties remain with the interpretation of RP-HPLC data and the development of a solvent system which will permit tasting of the fractions (Ardô and Gripon, 1991).”

• cites Ardô and Gripon, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Fluorescamine reacts at room temperature with water or primary amines, the latter reaction being far faster.

“It reacts at room temperature with water or primary amines, the latter reaction being far faster (Udenfried et al, 1972).”

• cites Udenfried et al, 1972Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Fluorescamine is used to quantify amino acids and peptides in the picomole range.

“Fluorescaminc (4-phenylspiro [furan-2 (3H), 1'-phthalan]-3,3'-dione) is used to quantify amino acids and peptides in the picomole range.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Comparison of chromatograms from different studies is difficult because various columns, elution conditions and detection wavelengths have been used.

“As var-0.20 ious columns, elution conditions and detection wavelengths have been used, comparison of chromatograms from different studies is difficult.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The level of water-soluble N (WSN) is a widely-used index of cheese ripening.

“The level of water-soluble N (WSN) is a widely-used index of cheese ripening (see Rank et al, 1985;Fox et al, 1995b)”

• cites Rank et al, 1985Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Fox et al, 1995bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

Mould and bacterial surface-ripened cheese varieties are characterized by an increase in pH during ripening; since the extractability of N varies with pH, an alternative method to water should be adopted.

“However, mould and bacterial surface-ripened varieties are characterized by an increase in pH during ripening; and since the extractability of N varies with pH, an alternative method should be adopted.”

• AssumptionRests on an assumption: The extractability of N varies with pH.
• AssumptionRests on an assumption: The pH of mould and bacterial surface-ripened cheese varieties increases during ripening.

It may state two separate claims as one.

Starter proteinases and peptidases play a relatively minor role in the hydrolysis of intact caseins and large polypeptides to water-soluble peptides, although they are active on many of the peptides released by chymosin or plasmin.

“Starter proteinases and peptidases play a relatively minor role in the hydro-Iysis of intact caseins and large polypeptides to water-soluble peptides, although they are active on many of the peptides released by chymosin or plasmin.”

It may state two separate claims as one.

If the influence of coagulant is studied, the formation of WSN and peptide profiles by urea-PAGE are suitable methods; since the coagulant does not produce free amino acids, their determination does not directly measure the contribution of the coagulant.

“For example, if the influence of coagulant is studied, the formation of WSN and peptide profiles by urea-PAGE are suitable methcds.Since the coagulant does not produce free amino acids, their determination does not directly measure the contribution of the coagulant.”

• AssumptionRests on an assumption: The coagulant does not produce free amino acids.

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

The rate and/or pattern of proteolysis may be influenced by location within a cheese, e.g., surface-ripened or young, brine-salted cheeses.

“The rate and/or pattern of proteolysis may be influenced by location within a cheese, eg, surface-ripened or young, brine-salted cheeses.”

• AssumptionRests on an assumption: The rate and/or pattern of proteolysis may be influenced by location within a cheese.

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

The increase in pH of mould-ripened cheese varieties means that pH 4.6 buffers are more suitable as primary extractants than water.

“The increase in pH of mould-ripened varieties means that pH 4.6 buffers are more suitable as primary extractants than water.”

• AssumptionRests on an assumption: The pH of mould and bacterial surface-ripened cheese varieties increases during ripening.

Probably not a substantial claim. The paper may give no reason why it holds.

Most of the techniques described above for the preparation of various fractions and the quantification of N soluble therein are quite time-consuming.

“Most of the techniques described above for the preparation of various fractions and the quantification of N which is soluble therein are quite time-consuming”

It may state two separate claims as one.

The described strategy provides information on the level and type of proteolysis from the initial hydrolysis of the caseins to the liberation of free amino acids and is suitable for most internal, bacterially-ripened cheese varieties.

“This strategy provides information on the level and type of proteolysis from the initial hydrolysis of the caseins to the Iiberation of free amino acids; and is suitable for most internai, bacterially-ripened cheese varieties.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

There is a growing demand for rapid methods for assessing cheese maturity because of their relative simplicity.

“Because of their relative simplicity, there is a growing demand for such rapid methods for assessing cheese maturity (Ardô and Meisel, 1991).”

• cites Ardô and Meisel, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Precipitation with ethanol may be used to fractionate cheese or to sub-fractionate water-soluble extracts, and should be preferred to the largely equivalent 12% TCA owing to the ease of removal of ethanol by evaporation.

“Precipitation with ethanol may be used to fractionate cheese or to sub-fractionate WSEs, and should be preferred to the largely equivalent 12% TCA owing to the ease of removal of ethanol by evaporation (Christensen et al, 1991).”

• cites Christensen et al, 1991Not checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The pH 4.6 method is more difficult to perform but may be easier to standardize.

“and although it is more difficult to perform, it may be easier to standardize (Fox, 1989).”

• cites Fox, 1989Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The Bradford method for protein determination is based on the colour change in Coomassie blue G250 when it reacts with proteins.

“The Bradford method for protein determination (Bradford, 1976) is based on the colour change in Coomassie blue G250 when it reacts with proteins.”

• cites Bradford, 1976 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Concentrations of TCA ranging from 2 or 2.5% to 12% have been used, depending on the degree of fractionation required, with larger peptides being soluble at lower TCA concentrations.

“Concentrations ranging from 2 or 2.5% (eg, Reville and Fox, 1978;O'Sullivan and Fox, 1990) to 12% (eg, Bican and Spahni, 1991;Folkertsma and Fox, 1992;Addeo et al, 1992;Bütikofer et al, 1993;Katsiari and Voutsinas, 1994;Picon et al, 1994;Yun et al, 1995) have been used, depending on the degree of fractionation required (Iarger peptides being soluble at the lower TCA concentrations).”

• cites Reville and Fox, 1978Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites O'Sullivan and Fox, 1990Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Bican and Spahni, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

Inclusion of CaCl2 in the NaCl solution should reduce the percentage N extracted and thus increase the selectivity of the method.

“Inclusion of CaCI 2 in the NaCI solution should reduce the percentage N extracted and thus increase the selectivity of the method (see Fox, 1989).”

• cites Fox, 1989Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

The N-terminal sequence (5-7 residues) is normally adequate to locate the origin of a peptide in the caseins, but other techniques must be used to determine its length.

“The N-terminal sequence (5-7 residues) is normally adequate to locate the origin of a peptide in the caseins, but other techniques must be used to determine its length.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

C-terminal sequencing could be used for determining peptide length but is not popular.

“C-terminal sequencing (eg, Iiberation of ami no acids over time by carboxypeptidase Y, eg, McSweeney et al, 1993b) could be used for this purpose but is not popular.”

• cites McSweeney et al, 1993bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

Since small peptides and free amino acids will be lost on dialysis, other methods for removal of TCA, such as repeated ether extraction or chromatography, are required and are laborious procedures.

“Since small peptides and free amino acids will be lost on dialysis, other methods for removal of TCA, eg, repeated ether extraction or sorne form of chromatography, are required and are laborious procedures (Fox, 1989).”

• cites Fox, 1989Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The precise location of peptides on unstained gels may be difficult since they cannot be compared directly with stained gels, the dimensions of which change on staining.

“However, the precise location of peptides on unstained gels may be difficult since the y cannot be compared directly with stained gels, the dimensions of which change on staining.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Amino acid sequencing by Edman degradation can also be used to identify peptides.

“Amino acid sequencing (either manual, eg, Mojarro-Guerra et al, 1991or automated, eg, McSweeney et al, 1994a;Singh et al, 1994Singh et al, , 1995Singh et al, , 1996) ) by Edman degradation can also be used to identify peptides.”

• cites Mojarro-Guerra et al, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites McSweeney et al, 1994aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Singh et al, 1994 sourceNot checked — no full text of the source

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

Individual small peptides are usually isolated by RP-HPLC.

“Individual small peptides are usually isolated by RP-HPLC.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The fractionation scheme used at present in this laboratory was developed for Cheddar cheese and may need to be modified for other varieties.

“This fractionation scheme was developed for Cheddar cheese and may need to be modified for other varieties.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Unless the peptide is relatively short, it may not be possible to determine its full sequence.

“However, unless the peptide is relatively short, it may not be possible to determine its full sequence.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Trifluoroacetic acid (TFA) as a precipitant or extractant for cheese peptides may be a useful alternative to TCA, and it has the major advantage of being easily removed by evaporation.

“Trifluoroacetic acid (CF 3 COOH; TFA) as a precipitant or ex tractant for cheese peptides may be a useful alternative to TCA, and it has the major advantage of being easily removed by evaporation.”

It may state two separate claims as one.

Mass spectrometry (MS) is more convenient for identifying peptides of known N-terminal sequence, although mass analysis alone is often insufficient to identify peptides since different casein-derived peptides can have the same amino acid composition (and hence mass).

“Mass spectrometry (MS) is more convenient for identifying peptides of known N-terminal sequence (eg, Singh et al, 1994Singh et al, , 1995Singh et al, , 1996)), although mass analysis alone is often insufficient to identify peptides since different casein-derived peptides can have the same ami no acid composition (and hence mass).”

• cites Singh et al, 1994 sourceNot checked — no full text of the source
• cites Singh et al, 1995Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Singh et al, 1996Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

There are few references to the use of TFA in the fractionation of cheese.

“Perhaps surprisingly, there are few references to its use in the fractionation of chee se.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The use of 70% ethanol, which gives similar precipitation levels, is preferable to TCA because ethanol can be readily removed by evaporation.

“The use of 70% ethanol, which gives similar precipitation levels, is preferable because ethanol can be readily removed by evaporation (Fox, 1989).”

• cites Fox, 1989Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The detailed study of proteolysis in cheese often requires that peptides in the initial extract be fractionated by a combination of the techniques discussed above.

“The detailed study of proteolysis in cheese often requires that peptides in the initial extract be fractionated by a combination of the techniques discussed above.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

The use of TFA as an ion-pair reagent in HPLC buffers is widespread.

“The use ofTFA as an ion-pair reagent in HPLC buffers is widespread (see below).”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The N-terminal sequence of electroblotted peptides can be determined readily, but it is necessary to remove peptides from the blotting membrane prior to mass spectrometric analysis.

“The N-terminal sequence (see below) of electroblotted peptides can be determined readily, but it is necessary to remove peptides from the blotting membrane prior to mass spectrometrie analysis.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

More than one casein-derived peptide may have the same amino acid composition and thus identification of peptides in a complex mixture from their amino acid composition alone is not recommended.

“However, more than one casein-derived peptide may have the same amino acid composition and thus identification of peptides in a complex mixture from their amino acid composition, alone is not recommended.”

It may state two separate claims as one.

Picric acid was considered the most suitable extractant for amino acids, but small peptides are also soluble in picric acid.

“It was considered to be the most suitable extractant for amino acids, but small peptides are also soluble in picric acid (Salji and Kroger, 1981).”

• cites Salji and Kroger, 1981Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Picric acid is a very discriminating protein precipitant.

“Picric acid (2, 4, 6-trinitrophenol) is also a very discriminating protein precipitant (Fox, 1989).”

• cites Fox, 1989Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

About 50% of the water-soluble nitrogen in a mature Cheddar was dialysable; the diffusate was completely soluble and the retentate 50% soluble in 70% ethanol.

“About 50% of the WSN in a mature Cheddar was dialysable; the diffusate was completely soluble and the retentate 50% soluble in 70% ethanoI.”

• cites Kuchroo and Fox, 1982bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

The water-soluble peptides in fractions obtained with SSA do not appear to have been characterized.

“The watersoluble peptides in the fractions obtained with SSA do not appear to have been characterized.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The most widely used PTA concentration is 5%.

“The most widelyused PT A concentration is 5%.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

5-Sulphosalicylic acid at 3% has been used to prepare extracts of cheese for amino acid analysis or as an index of amino acid nitrogen.

“5-Sulphosalicylic acid (2-hydroxy-5-sulphobenzoic acid; SSA), a discriminating protein precipitant, has been used at 3% to prepare extracts of cheese for ami no acid analysis (Reiter et al, 1969;Ramos et al, 1987), or as an index of amino acid N (Cliffe and Law, 1991).”

• cites Reiter et al, 1969Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Ramos et al, 1987Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Cliffe and Law, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

The A280 of the dialysate from unfractionated grated cheese correlated well with age and with 12% TCA-soluble and pH 4.6-soluble nitrogen.

“The A 28D of the dialysate correlated weil with age and with 12% TCA-soluble and pH 4.6-soluble N.”

• cites Sciancalepore and Alviti, 1987Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

No data were given on extraction levels or whether peptides were soluble in the Ba(OH)2/ZnSO4 method.

“No data were given on extraction levels or whether peptides were soluble.”

It may state two separate claims as one.

Phosphotungstic acid is a very discriminating protein precipitant; only free amino acids apart from lysine and arginine, and peptides less than about 600 Da, are soluble in 5% PTA.

“PT A)-H 1 S0 4 is a very discriminating protein precipitant; only free amino acids (apart from lysine and arginine), and peptides less than about 600 Da are soluble in 5% PT A (Jarrett et al, 1982).”

• cites Jarrett et al, 1982Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Ba(OH)2/ZnSO4 reagent has not been used extensively to fractionate cheese nitrogen nor to prepare samples for amino acid analysis.

“This reagent has not been used extensively to fractionate cheese N nor to prepare samples for amino acid analysis.”

It may state two separate claims as one.

Exhaustive dialysis of 96 h with four changes is a simple and effective method for partitioning water-soluble peptides and is suitable for relatively large samples.

“Kuchroo and Fox (1982b) found that exhaustive dialysis (96 h, four changes) was a simple and effective method for partitioning water-soluble peptides, and that it was suitable for relatively large samples.”

• cites Kuchroo and Fox, 1982bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Increased equipment requirements and long analysis times of about 10 h are likely to militate against widespread use of 2D-HPLC.

“although increased equipment requirements and long analysis times (-10 h) are likely to militate against the widespread use of 2D-HPLC.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Short PTA-soluble peptides in some cheese varieties have been studied.

“The short PT Asoluble peptides in sorne cheese varieties have been studied (Jarrett et al, 1982;Bican and Spahni, 1991;Gonzâlez de Llano et al, 1991).”

• cites Jarrett et al, 1982Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Bican and Spahni, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites González de Llano et al, 1991Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Free amino acids were extracted from Cheddar by Hickey et al using Ba(OH)2/ZnSO4.

“Free amino acids were extracted from Cheddar by Hickey et al (1983) using Ba(OH)z/ ZnS04'”

• cites Hickey et al, 1983Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. The paper may give no reason why it holds.

The enzymatic assay for ammonia does not appear to have been used in cheese analysis.

“However, this technique does not appear to have been used in cheese analysis.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The formol titration technique is a simple method for estimating amino groups in milk and may be used to measure the extent and rate of proteolysis.

“The formol titration technique is a simple method for estimating amino groups in milk and may be used to measure the extent and rate of proteolysis.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Changes in the buffering capacity of Emmental around pH 9 have been attributed to proteolysis.

“Changes in the buffering capacity of Emmental around pH 9 have been attributed to proteolysis (Lucey et al, 1993).”

• cites Lucey et al, 1993Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• AssumptionRests on an assumption: The buffering capacity of cheese increases during ripening owing to the formation of ammonia, amino, imino and carboxyl groups.

It may state two separate claims as one.

All peptides in a 10 kDa UF permeate are soluble in 2% TCA, but some peptides in the retentate are insoluble; the permeate contains no peptides detectable by PAGE with Coomassie blue G250, and 40-50% of the water-soluble nitrogen is permeable.

“Ali peptides in a 10 kDa UF permeate are soluble in 2% TCA, but sorne peptides in the retentate are insoluble (O' Sullivan and Fox, 1990); the permeate contains no peptides detectable by polyacrylarnide gel electrophoresis (PAGE) when stained using Coomassie blue G250, and 40-50% of the WSN is permeable.”

• cites O'Sullivan and Fox, 1990Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one.

Proteolysis has important consequences for the development of cheese texture due to cleavage of the protein matrix and flavour through the production of precursors of volatile flavour compounds and directly by the liberation of amino acids and certain peptides.

“Proteolysis has important consequences for the development of cheese texture due to cleavage of the protein matrix (Creamer and OIson, 1982;Lawrence et al, 1983) and f1avour through the production of the precursors of a number of volatile f1avour compounds and directly by the liberation of amino acids and certain peptides (see Fox et al, 1995a).”

• cites Creamer and Olson, 1982 sourceNot checked — no full text of the source
• cites Lawrence et al, 1983Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Fox et al, 1995aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The development of ammonia per se has not been used widely as an index of proteolysis.

“However, it is perhaps surprising that the development of ammonia per se has not been used more widely as an index of proteolysis.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Proteolysis is very limited in Pasta Filata varieties such as Mozzarella due to denaturation of enzymes during high-temperature stretching, while in mould-ripened varieties, particularly blue mould cheeses, proteolysis is extensive due to the presence of patent fungal proteinases.

“Proteolysis is very !imited in Pasta Filata varieties (eg, Mozzarella) due to denaturation of enzymes during high-temperature stretching, while in mould-ripened varieties (particularly blue mould cheeses) proteolysis is extensive due to the presence of patent fungal proteinases.”

It may state two separate claims as one.

Non-specific techniques are generally simple and are valuable for the routine assessment of cheese maturity.

“Such techniques are generally simple and are valuable for the routine assessment of cheese maturity.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Hydrolysis of caseins by the combined action of proteinases and peptidases in cheese ultimately leads to the liberation of free amino acids, which are considered important flavour compounds in many cheeses; their concentration varies widely with variety.

“Ultimately, the hydrolysis of caseins by the cornbined action of proteinases and peptidases in cheese leads to the liberation of free amino acids which are considered to be important flavour compounds in man y cheeses; their concentration varies widely with variety.”

It may state two separate claims as one.

Rejection of hydrophobic peptides by UF membranes and aggregation of small peptides are potential disadvantages of ultrafiltration.

“Rejection of hydrophobie peptides by UF membranes and aggregation of small peptides are potential disadvantages of this method.”

It may state two separate claims as one.

Ammonia, formed in cheese on the deamination of free amino acids, is an important product of proteolysis in certain cheese varieties such as Camembert or smear-ripened varieties, where it contributes to characteristic flavour and texture by neutralization of the cheese.

“Ammonia, formed in cheese on the deamination of free amino acids, is an important product of proteolysis in certain cheese varieties (eg, Camembert or smear-ripened varieties; Fox et al, 1995a) where it contributes to characteristic f1avour and texture (by neutralization of the cheese).”

• cites Fox et al, 1995aNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• AssumptionRests on an assumption: Ammonia is formed in cheese on the deamination of free amino acids.

It may state two separate claims as one.

Most authors have used ultrafiltration to fractionate the larger peptides in cheese, although very low molecular weight peptides have been isolated from bitter cheese extract using 0.5 kDa membranes and water-soluble nitrogen has been fractionated using 1 kDa cut-off membranes.

“Most authors have used UF to fractionate the larger peptides in cheese, although Visser et al (l983a,b) isolated very low molecular weight peptides from a bitter extract of cheese by UF on 0.5 kDa membranes, and Aston and Creamer (1986) used ultrafiltration with 1 kDa eut-off membranes to fractionate WSN.”

• cites Visser et al, 1983a,bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Aston and Creamer, 1986Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Early attempts to quantify free amino acids in cheese using paper chromatography with ninhydrin were only semi-quantitative.

“Early attempts to quantify free amino acids in cheese used paper chromatography developed », using ninhydrin (eg, Kosikowsky, 1951a, b) but such techniques were only semi-quantitative.”

• cites Kosikowsky, 1951a, bNot matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Membranes with nominal molecular weight cut-offs ranging from 0.5 to 10 kDa, most commonly, have been used for diafiltration to improve resolution.

“Many authors have used diafiltration to improve resolution, Membranes with nominal molecular weight cut-offs ranging from 0.5 to 10 kDa (most commonly) have been used.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

The potential of UF membranes with low molecular weight cut-offs below 1 kDa to fractionate the smaller peptides from cheese has not been extensively investigated.

“Despite sorne studies, the potential of UF membranes with low molecular weight cut-offs « 1 kDa) to fractionate the smaller peptides from cheese has not been extensively investigated.”

It may state two separate claims as one.

Dialysis has been superseded by ultrafiltration, which is faster, capable of handling larger samples, uses membranes of known molecular mass cut-off and reduces the problem of recovering peptides from a large volume of diffusate.

“While dialysis is a simple and useful technique for peptide fractionation, it has been superseded by ultrafiltration (UF) which is faster, capable of handling larger samples, uses membranes of known molecular mass eut-off and reduces the problem of recovering peptides from a large volume of diffusate.”

It may state two separate claims as one.

Non-specific methods provide adequate information on the overall extent of proteolysis and the general contribution of the various agents to proteolysis.

“Non-specifie methods provide adequate information on the overall extent of proteolysis and the general contribution of the various agents to proteolysis.”

Probably not a substantial claim. It may state two separate claims as one.

The thorough study of proteolysis necessitates the isolation and identification of peptides; therefore techniques which resolve individual peptides have received considerable attention in recent years.

“The thorough study of proteolysis necessitates the isolation and identification of peptides; therefore techniques which resolve individual peptides, such as electrophoresis and chromatography, have received considerable attention in recent years.”

It may state two separate claims as one.

UF allows fractionation of large samples and does not require solvents, both of which facilitate taste panel work.

“However, UF allows fractionation of large samples and does not require solvents, both of which facilitate taste panel work (Fox, 1989).”

• cites Fox, 1989Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

It may state two separate claims as one. The quote only partly states this claim.

Ammonia concentration in a non-protein fraction of Ulloa cheese was about 4 mg g-1 cheese dry matter and increased slightly during ripening.

“the concentration of ammonia was -4 mg g-l cheese dry matter and increased slightly during ripening.”

• cites Ordonez and Burgos, 1977Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.