(1) α-amylolysis kinetics of baguettes fitting and (2) relation with density the denser , the lower the in vitro IG (without â, or with â fibres). 0. 10. 20. 30. 40. 50. 60.
A reverse engineering approach of French breadmaking for nutritional purposes Chaunier L.a, Chiron H.a, Della Valle G.a**, Ducasse Mab, Kansou Kac, Ndiaye A.c, Réguerre A-L.a, Roussel P.d, Saulnier L.a, Shehzad A.a aINRA-BIA Nantes, bBIOFOURNIL Le Puiset Doré, cUMR INRA-CNRS-Université, US2B Bordeaux, dPolytech‘ Paris UPMC France
INTRODUCTION Processing
Mechanical properties
Structure
Sensory ☺ & Nutritional Properties
4000
E*, σ*
Co nt raint e en Pa
3000
2000
The National Plan for Health & Nutrition (PNNS) recommends the addition of wheat fibres and the decrease of the glycemic index (IG) of French bread. The addition of fibres in current French bread results in a loss of sensory properties => two main issues : 1) improving knowledge on the modification of wheat flour dough and bread properties, 2) achieving the necessary changes to craftsmen’s practices at different processing steps combining experimental approach and knowledge representation in order to integrate the processstructure-property relationships of breadmaking from the molecular to macroscopic scales.
1000
0 0
0.2
0.4
0.6
0.8
Déformation vraie = -ln(lf /l0)
0,9
MATERIALS & METHODS
* Proofing: porosity and stability (H/L) assessed by camera + image analysis
L
H
* Collecting knowledge on breadmaking practices. t=0
Closed questionnaire sent to 69 bakers located all over France
60
120
180
240 min
Porosité 0,8 0,7 0,6 0,5 0,4 0,3 0,2
* Formulation at pilot scale: ingredients and process follow-up
Baking: Bongard traditional electric deck oven (V=200L, P=21kW) at 250°C for 26 mn.
fibre addition +7,5% -> T80. Current (PCF) or traditional (PTF) french baguettes
0,1
temps (mn)
0,0 0
de
1
B ag ue tte
2
P C F + F ib r e s
3
PCF « D ense »
p a in
o r d in a ir e (P C F )
D
≈
Type
0 ,1 8 0 ,2 0
B ag ue tte
5
PT F +
T 6 5 + R e m o u la g e s
> 0 ,3 5
t r a d it io n (P T F )
F ib r e s
f a r in e
T é m o in I G f o r t A lv é o la g e r é g u lie r 7,5%
T en dan ce ty pe 8 0 A l v é o l a g e r é g u lie r
T 65 le v u r e / 3
T rès dense A l v é o l a g e r é g u lie r
0 ,2 5
T 65
A lv é o la g e ir r é g u lie r
0 ,2 5
T 6 5 + R e m o u la g e s 7 , 5 %
T en dan ce type 8 0 A l v é o l a g e ir r é g u lie r
6
P T F + F ib r e s t r a it é e s
0 ,2 5
T 6 5 + R e m o u la g e s 7 , 5 %
T en dan ce type 8 0 A l v é o l a g e ir r é g u lie r
7
P T F + F ib r e s « d e n s e »
0 ,3 5
T 6 5 + R e m o u la g e s 7 , 5 % D ose Levure/3
T rès dense A l v é o l a g e ir r é g u lie r
8
B a g u e t t e « le v a in »
0 ,3 5
T 65
T rès dense a l v é o la g e ir r é g u lie r
5,E+05
(1) α-amylolysis kinetics of baguettes fitting and (2) relation with density the denser , the lower the in vitro IG (without , or with fibres)
4,E+05 4,E+05
14
60
VO (h-1)
(%hyd) = a.(1-exp(-b.t)) Vo=a.b
50
2
σres
2
R = 0,88
3,E+05 3,E+05
(%) hydrolyse
90
120
150
180
Fibre addition increases: - mechanical properties of crust and crumb without modifying texture contrast (3) - density, crumb homogeneity and cell wall thickness (4), But it decreases dough stability during proofing (5).
3
12
40
60
with 10 to 20 adjustable pins, from force-displacement curve.
RESULTS & DISCUSSION
1
30
* Analyses at labscale: − α-amylolysis (in vitro IG): bread pieces (≈ 0.25cm3) 150mL water + .01µg amylase /mg starch pH7, at 37°C. V0 and starch easily degradable fraction (FFH) to compare to in vivo clinical assays. - Starch gelatinization and gluten aggregation: Thermal & mechanical analyses (DSC, DMA ≈ 5°C/mn). - Dough shear viscosity : creep-recovery tests on plane/plane controlled stress rheometer (σ = 10-1000 Pa). - Crumb grain (texture) :scanning (800dpi) about 10 slices x 3 baguettes + image analysis: similarity maps . - Overall mechanical properties : multi-indentation test by compression/relaxation test
Rem arques
T 65
D ose 4
de
ContRes (Pa)
Type
E E(Pa)
10
2,E+05 1,E+06
30
8
2,E+06
3,E+06
4,E+06
4
5,E+06
R2 = 0,9
20
6 10
temps (h)
densité 4
0 0
2
4
6
8
0,1
0,15
0,2
0,25
0,3
0,35
0,4
Flow sheet of the unit operations of breadmaking process after crossing with the results of the survey. Ellipses are unit operations and rectangles define dough states Mixing
Flour dough
Dividing Divided dough
First rising Ingredients : flour, water, salt, yeast and additives
Dough flow curves (6), fitted by Cross model (without , or with fibres) 8
Rounding
7
Light elongation
6
Bread making
Calibrated loave
Shaped loaves
Relaxation Final rising Relaxed loave Ready to bake loaves Shaping Scoring Scored loaves
Viscosité log(η η ) (Pa.s)
Dough make-up
Bread
η=
6
Calibrating
Fermented dough
0,70
5
H/Lmax 0,65
5
0,60
4
0,55
Témoin ? + 9% Fibres
3
internes
0,50
2
0,45 1
fermentation
0
-8
Baking
η0 . (1+( γ . )n) γ0
-6
-4
-2
Pétrissage, Façonnage
Vitesse de cisaillement
0 . 2 log( γ ) (s-1)
temps (min) 0,40 0
4
30
60
90
120
150
180
Conclusion: main findings and prospects 80
Viscosity increase due to fibre addition increases the density of dough before baking, and hence, its final value, after baking. This increase of density: - governs texture, by increasing modulus, in agreement with Gibson-Ashby’s model, allows to predict the mechanical properties of cellular solids.
Eapp (Pa)
Densité
1,E+06 0,1
1,0
- leads to a decrease of in vivo glycemic index (and in vitro), because of : (i) a limited starch destructuration due to a decrease of thermal flow, (ii) a reduced bread fragmentation during chewing, which hinders the accessibility to enzyme during digestion.
PCF
70
IG in vivo
1,E+07
60 PTF
50 2
R = 0,78
40 0,15
0,20
0,25
0,30
0,35
Densité
This work has been carried out in the frame of ANR-PNRA projects AQuaNuP (improving bread quality) and INCALIN (integrating knowledge in food industry), the participants of which are warmly acknowledged.
