Re: Gluten was: Smoking & Health

[Guest guest]

Perhaps someone could decipher the following for me:

J Agric Food Chem, 2004 Mar 10, 52(5), 1307 - 14

Gluten hydrolysis and depolymerization during sourdough fermentation;

Thiele C et al.; Hydrolysis and depolymerization of gluten proteins

during sourdough fermentation were determined . Neutral and acidified

doughs in which microbial growth and metabolism were inhibited were

used as controls to take into account the proteolytic activity of

cereal enzymes . Doughs were characterized with respect to cell

counts, pH, and amino nitrogen concentrations as well as the quantity

and size distribution of SDS-soluble proteins . Furthermore,

sequential extractions of proteins and analysis by HPLC and SDS-PAGE

were carried out . Sourdough fermentation resulted in a solubilization

and depolymerization of the gluten macropolymer . This

depolymerization of gluten proteins was also observed in acid aseptic

doughs, but not in neutral aseptic doughs . Hydrolysis of glutenins

and occurrence of hydrolysis products upon sourdough fermentation were

observed by electrophoretic analysis . Comparison of sourdoughs with

acid control doughs demonstrated that glutenin hydrolysis and gluten

depolymerization in sourdough were mainly caused by pH-dependent

activation of cereal enzymes.

#########

What is of interest to me is the last sentence, would " gluten

depolymerization " include gliaden or just the glutenins mentioned

right before? The way it is written the second phrase would seem to be

referring to the second network of gluten proteins, i.e. gliadin.

[Guest guest]

On 7/31/05, <slethnobotanist@...> wrote:

> Perhaps someone could decipher the following for me:

>

> J Agric Food Chem, 2004 Mar 10, 52(5), 1307 - 14

>

> Gluten hydrolysis and depolymerization during sourdough fermentation;

> Thiele C et al.; Hydrolysis and depolymerization of gluten proteins

> during sourdough fermentation were determined . Neutral and acidified

> doughs in which microbial growth and metabolism were inhibited were

> used as controls to take into account the proteolytic activity of

> cereal enzymes . Doughs were characterized with respect to cell

> counts, pH, and amino nitrogen concentrations as well as the quantity

> and size distribution of SDS-soluble proteins . Furthermore,

> sequential extractions of proteins and analysis by HPLC and SDS-PAGE

> were carried out . Sourdough fermentation resulted in a solubilization

> and depolymerization of the gluten macropolymer . This

> depolymerization of gluten proteins was also observed in acid aseptic

> doughs, but not in neutral aseptic doughs . Hydrolysis of glutenins

> and occurrence of hydrolysis products upon sourdough fermentation were

> observed by electrophoretic analysis . Comparison of sourdoughs with

> acid control doughs demonstrated that glutenin hydrolysis and gluten

> depolymerization in sourdough were mainly caused by pH-dependent

> activation of cereal enzymes.

>

> #########

>

> What is of interest to me is the last sentence, would " gluten

> depolymerization " include gliaden or just the glutenins mentioned

> right before? The way it is written the second phrase would seem to be

> referring to the second network of gluten proteins, i.e. gliadin.

The intro in the full-text would probably explain the background, but

it appears to me that they are sourdoughing a glutenin-contaning dough

(like rye), not a gliaden containing dough (like wheat), and that

glutenin aggregates into some sort of filament polymer. So when they

refer to depolymerization of gluten, they are referring to the

breakdown of the larger complex of individual glutenin proteins, and

when they refer to hydrolysis of glutenin, they are referring to the

breaking apart of residues within the glutenin to form smaller

peptides.

Again this is just my guess, but it sounds like glutenin aggregates

into a larger macro-structure like casein aggregates into micelles.

Chris

[Guest guest]

On 7/31/05, Masterjohn <chrismasterjohn@...> wrote:

> On 7/31/05, <slethnobotanist@...> wrote:

> > Perhaps someone could decipher the following for me:

> >

> > J Agric Food Chem, 2004 Mar 10, 52(5), 1307 - 14

> >

> > Gluten hydrolysis and depolymerization during sourdough fermentation;

> > Thiele C et al.; Hydrolysis and depolymerization of gluten proteins

> > during sourdough fermentation were determined . Neutral and acidified

> > doughs in which microbial growth and metabolism were inhibited were

> > used as controls to take into account the proteolytic activity of

> > cereal enzymes . Doughs were characterized with respect to cell

> > counts, pH, and amino nitrogen concentrations as well as the quantity

> > and size distribution of SDS-soluble proteins . Furthermore,

> > sequential extractions of proteins and analysis by HPLC and SDS-PAGE

> > were carried out . Sourdough fermentation resulted in a solubilization

> > and depolymerization of the gluten macropolymer . This

> > depolymerization of gluten proteins was also observed in acid aseptic

> > doughs, but not in neutral aseptic doughs . Hydrolysis of glutenins

> > and occurrence of hydrolysis products upon sourdough fermentation were

> > observed by electrophoretic analysis . Comparison of sourdoughs with

> > acid control doughs demonstrated that glutenin hydrolysis and gluten

> > depolymerization in sourdough were mainly caused by pH-dependent

> > activation of cereal enzymes.

> >

> > #########

> >

> > What is of interest to me is the last sentence, would " gluten

> > depolymerization " include gliaden or just the glutenins mentioned

> > right before? The way it is written the second phrase would seem to be

> > referring to the second network of gluten proteins, i.e. gliadin.

>

> The intro in the full-text would probably explain the background, but

> it appears to me that they are sourdoughing a glutenin-contaning dough

> (like rye), not a gliaden containing dough (like wheat), and that

> glutenin aggregates into some sort of filament polymer. So when they

> refer to depolymerization of gluten, they are referring to the

> breakdown of the larger complex of individual glutenin proteins, and

> when they refer to hydrolysis of glutenin, they are referring to the

> breaking apart of residues within the glutenin to form smaller

> peptides.

>

> Again this is just my guess, but it sounds like glutenin aggregates

> into a larger macro-structure like casein aggregates into micelles.

>

> Chris

Sounds like a fairly good guess to me since the full text does not

seem readily available, although I guess I could order it from the

University library.