Polymer’s functionality

SRC

Arnaud DUBAT

Better understand rheological analyses!

• Example : Alveograph

Gluten

Pentosans

StarchNativeDamaged

Moisture

Protein

Ash

Acid viscosity

P L

W

Alveograph

Kw

eon

, Mik

lus,

Sla

de,

& L

evin

e (2

00

3)

P L W Cookie quality

Flour batch A 36 102 108

Flour batch B 38 97 103

« final result is, at the minimum,

the sum of efforts of the

individual contributors »

Imagine a 3 runners relayTotal Time Analysis

Team Total Time

Winner 32 sec

Second 33 sec

Third 34 sec

Fourth 35 sec

TOTAL TIME is an indication of the TEAM PERFORMANCE It tells you HOW the team is performing but not WHY

Imagine a 3 runners relayIndividual Times Analysis

Team Total Time

1st Runner

2nd

Runner3rd Runner

Winner 32 sec 11 sec 11 sec 10 sec

Second 33 sec 11 sec 11 sec 11 sec

Third 34 sec 12 sec 12 sec 10 sec

Fourth 35 sec 9 sec 9 sec 17 sec

INDIVIDUAL RUNNER PERFOMANCE explains TEAM PERFORMANCE

You can only

IMPROVE the

TEAM PERFORMANCE

by ACTING on the

INDIVIDUAL PERFORMANCE

RHEOLOGICAL AND FINISHED PRODUCT LABORATORY TESTING

METHODS TELL YOU

HOWFLOUR WILL FUNCTION

SRC TELLS YOU

WHY

Investigating flour qualityWhat do we have so far?

Quantitative data

• Proteins, ash, fat…

Qualitative data

• Water absorption, tenacity, extensibility…

5 key Drivers for understandingPolymer functionality:

1. « Quantity » does not mean « quality »One might require a minimum « quantity » but this will never guarantee « quality » (think about bug infested wheat!)

2. « Quality » is defined by « Performance »Performance means : does the flour give a ‘good’ dough and the dough a ‘good’ final product. The ‘good » being different for every one.

3. Flour performance depends mainly on flour 3 main polymersGluten (Glutenins), starch (damaged), fibers (pentosans)

4. Rheological tools measure the combined effect of the 3 polymersWe speak about polymer « functionality ».

5. Measuring individual polymer functionality helps better understand dough performance.

It is like going from 2D image to 3D image.

Reminder on the wheat flour

3 main polymers : Protein

Starch (Damaged)

Pentosans

The wheat Kernel

• Components

• Bran (13-20%)– Fibers, ash

• Endosperm (75-85%)– Flour : starch, proteins, water

• Germ (2-4%)– Lipids, vitamins, enzymes…

Industrial interest of proteins

• 2 main proteins form the gluten:– Glutenins (tenacity)

– Gliadines (extensibility)

• These specific properties (tenacity & extensibility) of wheat gluten explain why wheat is a very atypical cereal and why wheat can be used to make bread …

Protein content vs bread volume

Proteins % Proteins %

French bread English bread

Volume Volume

To simplify protein effects

Glutenins(tenacity)

Gliadins(extensibility)

Gluten quality(gas retention)

Starch…in a nutschell

• Starch is a complex sugar…

• Starch is a chain of glucose molecule.

• Starch is an energy stock.

• Glucose is immediately available. It’s a ‘’fast’’ sugar

• Starch is hydrolyzed step by step. It’s a ‘’slow’’ sugar

Industrial interest of starches

• Starch forms fragile granules. During milling process, starch granules can be damaged and their properties change

• In the presence of water and heating, starch granules swell and form a viscous gel: it correspond to starch gelatinization

• During cooling, the starch molecules organisation change and the starch become harder. It correspond to starch retrogradation

Damaged starch rules!

• When a starch granule is damaged:

– Its water absorption capacity is multiplied by 10

– Starch molecules are more accessible to enzyme hydrolysis and lot of sugar are released. These sugar will be used by yeast

Pentosans

Hemicellulose

Pentosans

Xylan

ArabinoxylanFerulic acid

EsterCumaric Acid

Ester

Arabinan

Hexosan

BetaGlucan Galactan Mannanan

Pentosans effects on the dough

• Pentosans come to a great extentfrom the outer part of the wheatkernel (Bran)

• They represent between 2 to 3% of the flour.

• We divide Pentosan in two groups according to their solubility in water– Soluble (1/3)– Non soluble (2/3)

• Pentosans can bind up more than10 time their weight of water.

• Pentosans can link to Protein and reinforce the gluten network (via Ferulic acid)

• Effect on water absobtion diverge on the type of pentosan :– Positive with soluble pentosan– Negative with insoluble pentosans

(important and hererogenouintake, detrimental to Gluten formation).

Impact on dough rheological properties and final product quality

Proteins Damaged Starch Pentosans

Water intake ++ +++ ++++

Stiffness ++ ++ ++

Extensibility -/+ - --

Elasticity ++ --

Gas retention ++ - Soluble high loaf volumeInsoluble low loaf volume

Gas production No effect +++

Volume Depends ++ (if good retention) +/-

Colour - ++++

Stickiness/viscosity -- ++ (Excess) Soluble and insoluble fibers both increase dough consistency

Breakage (biscuit) ++ ++

Crispiness (final product) -- - -

Shelf Life (Bread) + + (Insoluble)

3 steps for determining QUALITY

Hot to measure polymer

Functionality?

Measuring polymer functionality?a sponge trick!

• Each flour polymer is able to specifically absorb a particular solvent:

• Sodium Carbonate for Damaged starch

• Sucrose for Pentosans

• Lactic Acid for Glutenins

• The principle will be to make flour swell into these solvents.

• Like a sponge, the polymer will absorb its solvent.

• Then we will force the solvent out of the polymer.

• If the polymer has high functionality it will retains a bigger quantity of solvent

• Like when you try to remove water for a sponge, there is always some water « linked » with the sponge.

OK, now: think like a sponge!

• Practical aspect:

1. The table 1 shows 2 flours having the same absorption BUT showing big differences in terms of polymer composition.

2. The Table 2 shows 2 flours having the same quantitative composition but different resulting absorption.

– This means that an information linking the « composition » and the « observed result » is missing : this missing information is the polymer functionality.

Table 1 Flour A Flour B

Proteins 9.31 12.77

Starch Dam. 26 23.5

Ash 0.67 0.85

Water Absorption

60.7 60.8

Table 2 Flour A Flour B

Proteins 11.41 11.44

Starch Dam. 25.3 25.6

Ash 0.65 0.62

Water Absorption

58.4 60.0

Continue to think like a sponge!

• If you can know the functionality of each polymer you are then in position to understand its individual contribution to the synergetic qualitative observation.

• You can then adopt the same thinking to analyze each polymer contribution to dough tenacity, extensibility, stickiness…

• Sometimes you want your result being related with one specific polymer and not the other ones• For example in cookie making you want to have the

lowest water absorption and you want to avoid absorption linked with Pentosans or damaged starch. Only absorption by Glutenins is « good absorption ».

• Now if you now which polymer is « good » or « bad » for your product you can select flour not only on quantity but also on functionality

Total Water

Absorption

Absorption by

pentosan

Absorption by glutenin

Absorption by damage

starch

Examples of specifications

020406080

100120140160

Water

Sucrose

Lactic acid

Sodium carbonate

Maraquetta

Chili 1

Chili 2

Chili 3

020406080

100120140160

Water

Sucrose

Lactic acid

Sodium carbonate

Pan Bread

UK 1

UK 2

USA 1

USA 2

USA 3

020406080

100120140160

Water

Sucrose

Lactic acid

Sodiumcarbonate

Steam bread

China 1

China 2

Korea 1

Korea 2

020406080

100120140160

Water

Sucrose

Lactic acid

Sodium carbonate

Cookie

USA

SRC map

0

20

40

60

80

100

120

140

Water

Sucrose

Lactic acid

Sodium carbonate

All samples

Artisan breadBaguette T55Baguette T65BaklavaBiscuitCake/cookiesMaraquettaNoodlesPan BreadPizza

Conclusion

• SRC test measures flour quality and functionality

• SRC is highly beneficial and complementary to quantitative and rheological analyses

• Make sure all players are running to their maximum capacity!

Thank you for your attention