NC 213: US Quality Grains Research ConsortiumKansas City, MOFebruary 18-19, 2015

PROCESSING PROPERTIES OF WHOLE-WHEAT DURUM FLOUR MILLED ON A CENTRIFUGAL MILL

Presenter: Lingzhu DengAdvisor: Dr. Frank Manthey

Cereal Science Graduate ProgramNorth Dakota State University

• Whole-wheat durum flour -Nutritious; -Healthy benefits.

• Whole-wheat durum flour Whole-wheat pasta -Milling & flour properties; -Direct grinding/ reconstitution; -Genotype selection.

• Whole-wheat durum flour milling -Grinding each portion; -Mill type.

INTRODUCTION

• Milling techniques is the most concern in whole-wheat milling that it determines particle size distribution of whole-wheat flour.

• Excessive grinding -Damages to starch granule, protein, and unsaturated fatty acids

under heat generation (Prabhasankar and Rao, 2001);

-is destructive on water binding ability and dough network;

-All above results in high amylose leaching and cooking loss.

Prabhasankar, P., and Rao, P.H. 2001. Effect of different milling methods on chemical composition of whole wheat flour. Eur. J. Food Res. Technol. 213: 465-469.

INTRODUCTION

• Retsch Mill (ZM 200, Retsch, Germany) -Feeding -Feeding capacity: 2-4 kg; -Grinding -Impact and shear; -Cooling part -Air stream cools flour.

INTRODUCTION

OBJECTIVES

• To determine milling configuration of whole-wheat durum flour on a centrifugal mill which to have similar fineness as commercial whole-wheat flours.

• To evaluate whole-wheat pasta quality using whole-wheat durum flour on different milling configurations.

WHOLE-WHEAT FLOUR MILLING• Materials -Bulk of durum samples (ND, 2012).

• Methods

-Milling Screen Aperture: 250, 500, 1,000 µm; -Rotor speed: 6,000, 9,000, 12,000, 15,000, 18,000 rpm; -Grain moisture: 12%.

Test Weight(lb/bu)

1000-kernel

weight(g) Moisture

(%)Protein

(%)

kernel size (%)

Large Medium Small

62.3 37.9 9.0 13.9 58 38 4

• Quality Parameters

-Flour and mill temperature: thermometer (TN408LC, Metris, NJ); -Flour moisture: AACCI Method 44-15.02; -Flour starch damage: AACCI Method 76-31.01; -Flour color: CIE lightness (CR310, Minolta, NJ); -Flour particle size distribution: Retsch sieve vibratory shaker (Retsch, Germany) .

WHOLE-WHEAT FLOUR MILLING

AACC, Approved methods of the American Association of Cereal Chemists. 2010. 10th Ed. Methods (44-15.02), and (76-31.01). AACC, St. Paul, MN.

• Statistical Analysis -Experimental design: RCBD with split plot arrangement. Whole plot was mill screen and subplot was rotor speed. -ANOVA and mean separation (LSD) have been done at P<0.05.

WHOLE-WHEAT FLOUR MILLING

WHOLE-WHEAT FLOUR MILLING

• Flour Temperature

760C

No vacuum cooling250 μm, 12,000 rpm

With vacuum cooled

6,000 9,000 12,000 15,000 18,0000

20

40

60

80

100

250 μm500 μm1,000 μm

Rotor Speed (rpm)

Flou

r Tem

pera

ture

(0C)

WHOLE-WHEAT FLOUR MILLING• Mill Surface Temperature

980C

No vacuum cooling250 μm, 12,000 rpm

With vacuum cooled

6,000 9,000 12,000 15,000 18,0000

20

40

60

80

100

250μm500μm1000μm

Rotor Speed (rpm)

Mill

Sur

face

Tem

pera

ture

(0C)

WHOLE-WHEAT FLOUR MILLING

• Moisture

6,000 9,000 12,000 15,000 18,0008

9

10

11

12

13

250μm500μm1000μm

Rotor Speed (rpm)

Moi

stur

e (%

)

• Particle Size Distribution

WHOLE-WHEAT FLOUR MILLING60

0µm

500µ

m

425µ

m

250µ

m

150µ

m

100µ

m

50µm

<50µ

m250µm

0

10

20

30

40

50

60

70

6,00012,00018,000

%

600µm 500µm 425µm 250µm 150µm 100µm 50µm <50µm1000µm

0

10

20

30

40

50

60

70

6,00012,00018,000

Sieve Mesh Size (μm)

%

250 μm 500 μm

1,000 μm

600µ

m

500µ

m

425µ

m

250µ

m

150µ

m

100µ

m

50µm

<50µ

m

500µm

0

10

20

30

40

50

60

70

6,00012,00018,000

%

WHOLE-WHEAT FLOUR MILLING

• Starch Damage • Lightness

6,000 9,000 12,000 15,000 18,00068

70

72

74

76

78

80

82

84

250 μm500 μm1,000 μm

Rotor Speed (rpm)

Ligh

tnes

s

6,000 9,000 12,000 15,000 18,0000

3

6

9

12

15

250μm500μm1000μm

Rotor Speed (rpm)

Star

ch D

amag

e (%

)

WHOLE-WHEAT FLOUR MILLING

Fineness&Brightness

HeatStarch Damage

250 µm12,000 rpm,

500 µm 18,000 rpm,

1,000 µm18,000 rpm

WHOLE-WHEAT RETSCH FLOUR VS COMMERICAL FLOUR

• Particle Size Distribution

600µm500µm

425µm250µm

150µm100µm

50µm<5

0µm0

10

20

30

40

50

60

250 µm 12,000 rpm

Dakota Mill WWF

Ultragrain

Sieve Mesh Size (µm)

%

600µm500µm

425µm250µm

150µm100µm

50µm<5

0µm0

10

20

30

40

50

60

500 µm 18,000 rpm

Dakota Mill WWF

Ultragrain

Sieve Mesh Size (µm)

%

North Dakota Mill whole-wheat flour (North Dakota Mill, Fargo, ND); and Ultragrain (Ardent Mills, Omaha, NE)

WHOLE-WHEAT RETSCH FLOUR VS COMMERICAL FLOUR

• Color and Starch Damage

Lightness Starch Damage (%)

Ultragrain 84.2 5.6250 µm, 12,000 rpm 82.6 9.7Dakota Mill WWF 77.7 3.7500 µm, 18,000 rpm 78.5 5.5

WHOLE-WHEAT PASTA PROCESSING4 Durum CultivarsGrain moisture: 12%Mill screen: 250 and 500 µm.

Semi-commercial pasta extruder (DeMaCo, Melbourne, FL)Laboratory dryer (730C, 10h)

Pasta color: Hunter lightness (CR310, Minolta , NJ);Cooked Quality: AACCI Method 66-50.01.

FLOUR MILLING

HYDRATION33%

PASTA EXTRUSION & DRYING

QUALITY EVALUATION

STATISTICAL ANALYSIS

RCBD with split plot arrangement. Whole plot was mill screen and subplot was durum cultivar. ANOVA and mean separation (LSD) at P<0.05.

AACC, Approved methods of the American Association of Cereal Chemists. 2010. 10 th Ed. Methods (66-50.01). AACC, St. Paul, MN.

WHOLE-WHEAT PASTA PROCESSING

Cultivar Pasta Lightness Firmness (g cm)∙ Cooking Loss (%)

250 µm 500 µm 250µm 500µm 250µm 500µm

Maestrale 37.5 37.1 5.3a 3.8b 8.5a 7.9a

Saragolla 37.4 36.3 4.2a 3.8b 10.1a 8.6b

Tioga 35.5 35.0 4.5a 3.9b 9.9a 8.5b

Carpio 34.3 33.7 5.8b 5.3b 7.9a 7.5a

Ultragrain 33.6 5.1 8.3

WHOLE-WHEAT PASTA PROCESSING

Cultivar Firmness (g cm)∙ Cooking Loss (%)

250 µm 500 µm 250 µm 500 µm

Maestrale 5.3A 3.8B 8.5A 7.9A

Saragolla 4.2A 3.8B 10.1A 8.6B

Tioga 4.5A 3.9B 9.9A 8.5B

Carpio 5.8A 5.3B 7.9A 7.5A

Ultragrain 5.1 8.3

To compare cooking properties means within a cultivar.

TO CONCLUDE…

Milling Configuration

250 µm and 12, 000 rpm

500 µm and 18, 000 rpm

Pasta Quality

Greater firmness with

250 µm

THANK YOU