STUDY OF WHEAT POWDER REACTIVITY AND

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1 Moustafa SAAD Montpellier, June 7 th 2011 STUDY OF WHEAT POWDER REACTIVITY AND AGGLOMERATION MECHANISMS: CONTRIBUTION OF PARTICLES PHYSICAL AND CHEMICAL CHARACTERISTICS APPLICATION ON CEREAL-BASED FOOD(COUSCOUS) Bernard CUQ Thesis Director Montpellier SupAgro 1

2 Wheat is the most consumed cereal in Europe Introduction Endosperm Germ Outer layers Wheat semolina Main components: Starch, Protein, Lipids Couscous 2

3 Wheat is the most consumed cereal in Europe Introduction Endosperm Germ Outer layers Wheat semolina Main components: Starch, Protein, Lipids Couscous 3

4 Introduction PARTICLE 4

5 Introduction PARTICLE INTRINSIC CHARACTERISTICS MATTER Bulk chemical composition OBJECT Size, Morphology SURFACE Surface Chemical Composition 5

6 Introduction PARTICLE INTRINSIC CHARACTERISTICS MATTER Bulk chemical composition OBJECT Size, Morphology SURFACE Surface Chemical Composition 6

7 Introduction PARTICLE INTRINSIC CHARACTERISTICS MATTER Bulk chemical composition OBJECT Size, Morphology SURFACE Surface Chemical Composition 7

8 Thermal Introduction PARTICLE Hydric Mechanical Chemical 8

9 Thermal Introduction PARTICLE Hydric Mechanical Chemical REACTIVITY 9

10 Introduction PARTICLE Hydric Mechanical Agglomeration 10

11 Introduction PARTICLE Hydric Mechanical MECHANISM Agglomeration 11

12 Introduction Couscous: - Wheat-based food product - Homemade production - Industrial production -A lot of empiricism 12

13 Introduction Couscous: - Wheat-based food product - Homemade production - Industrial production -A lot of empiricism Drying Cooking Agglomeration 13

14 Introduction Couscous: - Wheat-based food product - Homemade production - Industrial production -A lot of empiricism Drying Cooking Agglomeration 14

15 Introduction PARTICLE Hydric Mechanical MECHANISM Wet agglomeration mechanism PRODUCT Quality, Yield 15

16 Introduction PARTICLE Hydric Mechanical MECHANISM Wet agglomeration mechanism PRODUCT Quality, Yield 16

17 Objective & Plan MOUS s PhD Shape Surface Composition Particle 17

18 Objective & Plan MOUS s PhD Shape Surface Composition Particle Wet agglomeration Mechanism 18

19 Objective & Plan MOUS s PhD Shape Surface Composition Particle Wet agglomeration Mechanism Impact of wet agglomeration on couscous quality Impact of wet agglomeration on couscous yield Product 19

20 I. Particle scale -Shape -Measurement -Impact of particle diameter. -Surface chemical composition - Measurement 20

21 Particle Scale: Morphology Particle Disperser Malvern England EK 100 Materials & Methods Image Analyzing System (IAS) Microscope LEICA DM6000M IMAQ Vision NATIONAL INSTRUMENTS

22 Particle Scale: Morphology Particle Disperser Malvern England EK 100 Materials & Methods Image Analyzing System (IAS) Microscope LEICA DM6000M IMAQ Vision NATIONAL INSTRUMENTS

23 Particle Scale: Morphology Materials & Methods Elongation 1 Circularity 1 Compactness 0 1 Convexity

24 Particle Scale: Morphology Results "Simple" shape for the small particles Heterogeneous shapes for the larger particles 24

25 II. Mechanisms scale -Description of wet agglomeration mechanisms of durum wheat semolina. 25

26 Mechanism Scale: Agglomeration Materials & Methods -At the laboratory scale Semolina Size classification Water Fraction No. 1 Wet Mass Fraction No. 2 Fraction No. 3 Fraction No. 4 Vertical mixer 26

27 Mechanism Scale: Agglomeration Materials & Methods -At the laboratory scale Semolina Size classification Water Fraction No. 1 Wet Mass Fraction No. 2 Fraction No. 3 Fraction No. 4 Vertical mixer 1. Weighting 2. Size distribution 3. Solid Volume Fraction Wet Mass All fractions Dispersion. Image acquisition. Image processing. 27

28 Mechanism Scale: Agglomeration Results 200 µm 600 µm 1200 µm 2000 µm Particles 0.2 mm Nuclei 0.6 mm 1 mm Agglomerates 1 mm 3 mm Dough pieces 3 mm 28

29 Mechanism Scale: Agglomeration Results 200 µm 600 µm 1200 µm 2000 µm Particles 0.2 mm Nuclei 0.6 mm 1 mm Agglomerates 1 mm 3 mm Dough pieces 3 mm Weight ratio (%) Semolina particles Nuclie Agglomerates Dough pieces plastic limit Bed bulk water content (g water/ g dry matter) 29

30 Mechanism Scale: Agglomeration Results 200 µm 600 µm 1200 µm 2000 µm Particles 0.2 mm Nuclei 0.6 mm 1 mm Agglomerates 1 mm 3 mm Dough pieces 3 mm Nucleation Coalescence Percolation 30

31 Mechanism Scale: Agglomeration Results 200 µm 600 µm 1200 µm 2000 µm Particles 0.2 mm Nuclei 0.6 mm 1 mm Agglomerates 1 mm 3 mm Dough pieces 3 mm Nucleation Coalescence Fractal growth Percolation 31

$Percolation La croissance fractal$ successives à partir d un

32 Mechanism Scale: Agglomeration Results 200 µm 600 µm 1200 µm 2000 µm Particles 0.2 mm Nuclei 0.6 mm 1 mm Agglomerates 1 mm 3 mm Dough pieces 3 mm Nucleation Coalescence Fractal growth Percolation La croissance fractal s effectue par itération successives à partir d un générateur (nuclie), lui même constitué par l association d éléments à l échelle inférieur initiateur particules Nucleation Fractal Growth 32

33 Mechanism Scale: Agglomeration Results 200 µm 600 µm 1200 µm 2000 µm Particles 0.2 mm Nuclei 0.6 mm 1 mm Agglomerates 1 mm 3 mm Dough pieces 3 mm Nucleation Coalescence Fractal growth Percolation 33 -This equation allows us to calculate the median diameter of the agglomerate according to their water content

34 III. Product Scale -Couscous production in pilot scale -Study the impact of wet agglomeration conditions on agglomeration yield and couscous final quality. 34

Product Scale: Quality & Yield - Couscous production pilot Mixer Materials & Methods Roller Steamer

Homogenization 2min - Production conditions 2000-1500-1000µm sieves 10 min, 25 0 C, -3 types of

Bar 80% RH, 70 0 C, 60 min -Measurements & characterization Yield Couscous Characterization:

Scanning electron microscopy imaging(sem), - Water absorption index(wai is an indication of water

35 Product Scale: Quality & Yield - Couscous production pilot Mixer Materials & Methods Roller Steamer Drier 1. Homogenization 2 min 2. Continuous water addition 3. Homogenization 2min - Production conditions µm sieves 10 min, 25 0 C, -3 types of semolina (small, average, large size) - 3 hydration rates (low, average, high) 8 min, C, 1 Bar 80% RH, 70 0 C, 60 min -Measurements & characterization Yield Couscous Characterization: -Granulometricanalyses(expressedasd 50 ), -Colormeasurements(expressedbyL *,a *,b * values) - Scanning electron microscopy imaging(sem), - Water absorption index(wai is an indication of water absorption capabilities of couscous grains), - Water solubility index(wsi is an indication the formation of undesirable soluble), - Swelling capacity. 35

Product Scale: Quality & Yield Results COUSCOUS

Capacity Color L * a * b * Applied hydration rate 32.

5% Hydration rate applied is 35% Small size Semolina 150

7 5.0 ± 0.3 400 ± 21.2 66.2 ± 0.43 2.50 ± 0.16 32.9 ± 0.

84 ± 0.03 34.3 ± 0.1 large size semolina 427 ± 5.3 3.2 ± 0.

3 Impact of hydration rate 32.5 % 457 ± 5.1 4.6 ± 0.

2 35 % 454 ± 3.1 4.2 ± 0.3 388 ± 3.5 71.8 ± 0.03 0.

36 Product Scale: Quality & Yield Results COUSCOUS CHRACTERISTICS COUSCOUS MICROSTRUCTURE WAI WSI Swelling Capacity Color L * a * b * Applied hydration rate 32.5% 35% 37.5% Hydration rate applied is 35% Small size Semolina 150 µm Impact of particle size small size semolina 430 ± ± ± ± ± ± 0.1 Native 454 ± ± ± ± ± ± 0.1 large size semolina 427 ± ± ± ± ± ± 0.3 Impact of hydration rate 32.5 % 457 ± ± ± ± ± ± % 454 ± ± ± ± ± ± % 471 ± ± ± ± ± ± 0.0 Semolina Particle size d µm 299 µm 150 µm hydration rate and particle size affect production yield WAI, WSI, Swelling capacity, and color couscous microstructure 36

37 Conclusion MOUS s PhD Shape Surface Composition Particle Wet agglomeration Mechanism Impact of wet agglomeration on couscous quality Impact of wet agglomeration on couscous yield Product 37

38 MERCI POUR VOTRE ATTENTION 38

39 PUBLICATIONS - M. Saad, L. Galet, B. Cuq. Impact of agglomeration conditions on the quality of couscous produced in pilot scale (in preparation) - A. Duri, M. George, M. Saad, E. Gastaldi, M. Ramonda, B. Cuq. Atomic Force Microscopy study of adhesion forces between wheat flour particles and constituents (in preparation) - M. Saad, A. Barkouti, E. Rondet, T. Ruiz, B. Cuq (2011). Study of agglomeration mechanisms of food powders: Application to durum wheat semolina, Journal of Powder Technology, 208 (2): M. Saad, C. Gaiani, M. Mullet, J. Scher, B. Cuq (2011). X-ray photoelectron spectroscopy for wheat powders: measurement of surface chemical composition, Journal of Agriculture and Food Chemistry, 59 (5): M. Saad, A. Sadoudi, E. Rondet, B. Cuq (2011). Morphological characterization of wheat powders, how to characterize the shape of particles? Journal of Food Engineering, 102:

BIO & PHARMA ANALYTICAL TECHNIQUES. Chapter 5 Particle Size Analysis

BIO & PHARMA ANALYTICAL TECHNIQUES Chapter 5 by Dr Siti Umairah Mokhtar Faculty of Engineering Technology umairah@ump.edu.my Chapter Description Aims Discuss theory, principles and application of analytical