Title: Influence of Milling Method on the Physical and Functional Properties of Yellow

Pea Flour Used in Cookies Author(s): L. Bourré, H. Maskus, R. DeStefano, L. Malcolmson

Citation: AACC International Annual Meeting, 30 September - 3 October 2012, Hollywood, Florida, U.S.A. Poster 232-P.

Link: http://www.aaccnet.org/meetings/Documents/2012Abstracts/p12ma232.htm

Influence of Milling Method on the Physical and Functional Properties of Yellow Pea Flour Used in Cookies

L. Bourré, H. Maskus, R. DeStefano and L. MalcolmsonCanadian International Grains Institute (Cigi), 1000-303 Main Street, Winnipeg, Manitoba, Canada R3C 3G7

Introduction

The addition of whole pea flour to wheat flour can greatly enhance the nutritional profile of wheat flour by increasing fibre, protein and mineral content of the blended flour. However, the presence of pea flour can also affect the functional properties of the blended flour which in turn can affect end-product quality. Both the physical and functional properties of pea flour can be affected by the method used to mill the peas into flour. Research is limited on how different milling methods influence flour quality and ultimately end-product quality. Understanding how milling method affects flour quality will enable processors to successfully formulate food products with whole yellow pea flour.

Objectives

• To determine the effects of milling method (hammer, stone, pin, roller) on the physical and functional properties of whole yellow pea flour. • To examine the effects of milling method on the quality of cookies made from a blend of 30% whole yellow pea flour and 70% soft wheat flour.

Materials and MethodsSamples and Flour Analysis • Whole yellow peas (WYP) (CDC Meadow var.) were commercially milled using four different milling technologies (hammer, stone, pin and roller). Fine and coarse pin milled flours were produced for a total of five WYP flours. • Soft wheat flour was obtained from a commercial source and was used as the control and for blending with the WYP flours. • Blends of 30/70% WYP/wheat flour were prepared and analyzed along with the wheat and WYP flours for: • Average Particle Size - Malvern Scirocco 2000 Mastersizer, with volume weighted mean reported • Starch Damage - Chopin SDmatic, expressed as a percentage of iodine absorbed (Ai%) • Water Absorption Capacity - Beuchat (1977), expressed as g water/g flour • Peak Viscosity - AACC 76-21, Perten Rapid Visco Analyzer, reported as Rapid Visco Units (RVU)

Cookie Production and Analysis • Wire-cut cookies were made according to AACC standard method 10-53. Cookies were baked for 8 minutes at 375°F. • Cookies were evaluated for width, thickness and spread according to AACC standard method 10-53. • Cookie colour was measured using a Minolta CR-310 Colorimeter using a D65 illuminant. • Instrumental texture was evaluated using the TA-XT2 Texture Analyzer (Stable Micro System). The three-point bend test was performed using an adjustable bridge (TA-92) with supports 45mm apart and a rounded end (TA-42) knife probe.

Statistical Analysis • Significant differences among flour treatments were determined using the Tukey-Kramer test (SAS, JMP version 8).

Results and DiscussionFlour Properties • Particle size of the WYP flours and blended flours was influenced by milling method (Tables 1 and 2). • Greater levels of starch damage and water absorption capacity were found in WYP flours which had smaller particle sizes. • Among the flour blends, only the blend with WYP roller milled flour had significantly higher starch damage compared to the control flour. All blends had significantly higher water absorption capacity values than the control flour which was likely due to the presence of the hull fraction in the pea flours. • Peak viscosities of the flour blends were significantly lower than the control flour. With the exception of the pin milled fine flour blend, the peak viscosities decreased as the particle size of the flour blend increased.

Cookie Dimensions • Cookies made from stone, roller and pin milled fine flours were significantly different from the control in width, thickness and spread (Figures 1-3). • Cookies made from the pin milled fine flour had the smallest width and the greatest thickness while cookies made with the stone milled flour had the greatest width and the smallest thickness. • Cookies made from the roller milled and pin milled fine flours had the smallest spread whereas the cookies made from stone flour had the greatest spread.

Cookie Colour • All of the cookies made with WYP flours had lower L* values compared to the control cookie (Figure 4). • Cookies made with stone milled flour had the lowest L* value whereas the cookies made from pin milled coarse flour had the highest L* value.

Cookie Texture • The majority of the cookies made with WYP flours were firmer than the control with the exception of the cookies made from hammer and stone milled flours (Figure 5). • As expected, firmness of the cookies was related to cookie dimensions. • Cookies made with pulse flours with a larger particle size were closer to the control cookies in terms of firmness.

Conclusions • Milling method significantly affected the physical and functional characteristics of WYP flour as measured by flour particle size, starch damage and water absorption capacity. • Interestingly, when the pea flours were blended with wheat flour, despite the differences in particle size, there were no significant differences in starch damage or water absorption capacity among the blended flours. • Differences in particle size did result in significant differences in cookie dimensions and firmness. Flour blends that had a larger particle size produced cookies that were wider, less thick, had a greater spread and required less force to break. • WYP flour can be successfully added to cookie formulations. However, it is important that flour specifications be taken into account to ensure optimum results.

ReferencesAACC International. Approved Methods of Analysis, 11th Ed. Method 10-53.01. Baking quality of cookie flour – Macro wire cut formulation. Approved November 3rd, 1999. AACC International, St. Paul, MN. AACC International. Approved Methods of Analysis, 11th Ed. Method 76-21.01. General pasting methods for wheat or rye flour or starch using the rapid visco analyser. Approved November 3rd, 1999. AACC International, St. Paul, MN. Beuchat, L.R. (1977). Functional and electrophoretic characteristics of succinylated peanut flour protein. J. Agri. Food Chem., 25: 258-261.

Acknowledgements

Funding for this project has been provided by the Canadian Special Crops Association, Saskatchewan Pulse Growers, Alberta Pulse Growers and by Agriculture and Agri-Food Canada through the Canadian Agricultural Adaptation Program.

The technical assistance provided by Cigi’s Analytical Services staff is greatly appreciated. Special thanks to Cigi’s Communications staff for poster design and layout.

Table 2: Physical and Functional Properties of Wheat Flour and 30/70% Blends of Whole Yellow Pea (WYP) and Wheat Flour Particle Size Starch Damage WAC1 Peak Viscosity (μm) (Ai%) (g/g) (RVU)

Wheat Control 87.15 91.80 ± 0.12 a 0.60 ± 0.06 a 356.50 ± 7.78 aWYP Fine Pin Milled/Wheat 98.83 92.51 ± 0.04 ab 0.73 ± 0.01 b 271.50 ± 0.71 bcWYP Roller Milled/Wheat 123.38 92.90 ± 0.40 b 0.72 ± 0.00 b 286.00 ± 2.83 bWYP Coarse Pin Milled/Wheat 156.00 91.76 ± 0.44 a 0.73 ± 0.01 b 280.50 ± 4.95 bWYP Hammer Milled/Wheat 212.23 91.86 ± 0.22 ab 0.75 ± 0.01 b 257.00 ± 1.41 cdWYP Stone Milled/Wheat 278.49 91.57 ± 0.05 a 0.75 ± 0.01 b 243.00 ± 5.66 d

1WAC = Water Absorption CapacityValues with the same letter within a column are not significantly different (p<0.05)

Table 1: Physical and Functional Properties of Wheat and Whole Yellow Pea (WYP) Flours

Flour Particle Size Starch Damage WAC1

Treatment (μm) (Ai%) (g/g)

Wheat Control 87.15 91.80 ± 0.12 a 0.60 ± 0.06 aWYP Fine Pin Milled 97.10 92.57 ± 0.11 a 1.34 ± 0.01 bWYP Roller Milled 236.82 95.77 ± 0.09 b 1.41 ± 0.00 bcWYP Coarse Pin Milled 276.82 95.33 ± 0.14 b 1.31 ± 0.00 bWYP Hammer Milled 274.19 90.30 ± 0.82 a 1.57 ± 0.07 cWYP Stone Milled 595.65 84.96 ± 1.29 c 1.88 ± 0.05 d

1WAC = Water Absorption CapacityValues with the same letter within a column are not significantly different (p<0.05)

Control Stone Pin Mill-Coarse

Pin Mill-Fine

Roller Hammer

Height of cookies made with whole yellow pea flour.

Colour measurement using a Minolta

CR-310 Colorimeter.

Texture analysis evaluated using a three-point

bend test.

www.cigi.ca@CigiWinnipeg Cigi

Figure 1: Width (mm) of cookies made with 30% whole yellow pea flour milled using different

milling methods (control = 100% wheat flour). Values with the same letter are not

significantly different (p<0.05).

mm

cd

ab

aa

10.5

10

9.5

8

7.5

d

9

8.5

mm

Figure 2: Thickness (mm) of cookies made with 30%

whole yellow pea flour milled using different milling

methods (control = 100% wheat flour). Values with

the same letter are not significantly different

(p<0.05).

d

a10

9

8

6

0

Spre

ad(w

idth

/thi

ckne

ss)

bc ab

cdd

7

5

4

3

2

1

Figure 3: Spread of cookies made with 30% whole yellow pea flour

milled using different milling methods (control = 100%

wheat flour). Values with the same letter are not

significantly different (p<0.05).

bc

d

80

78

76

72

60

L*

a

cb

c74

70

68

66

64

62

Figure 4: L* values of cookies made with 30% whole yellow pea flour milled using different

milling methods (control = 100% wheat flour). Values with the same letter are not

significantly different (p<0.05).

ab

c

4

3.5

2.5

0

Peak

For

ce (k

g) cc

b

a

3

2

1.5

1

0.5

Figure 5: Force (kg) required to break cookies made with

30% whole yellow pea flour milled using different milling methods (control = 100% wheat flour). Values with the same letter are not

significantly different (p<0.05).