USE OF WHOLE GRAIN FLOURS IN THEPRODUCTION OF PASTA

A. Sarkar, P. Ebbinghaus, A.-S. Bellido, C. Lukie and L. Malcolmson, Canadian International Grains Institute, 1000 - 303 Main Street, Winnipeg, MB, R3C 3G7

INTRODUCTION & OBJECTIVEChanges to the recommended daily intake of dietary fibre haveresulted in the need for foods with enhanced dietary fibre to help consumers meet their daily requirements. Addition of whole grain (WG) barley flour and WG pulse flours offers interesting alternatives to traditional fibre sources. WG barley flour is a good source of insoluble and soluble β-glucan fibre and WG pulse (pea, lentil, chickpea and bean) flours are good sources of insoluble fibre. The objective of this study was to evaluate the processing characteristics and quality of pasta made by partially substituting durum semolina with WG barley and pulse flours.

MATERIALS & METHODSFlours • CDC McGwire and Millhouse (both 2-row hulless, regular starch) and CDC Fibar (2-row hulless, zero amylose starch) were hammer milled into WG flour at Dover Mills, Saskatoon, SK. • Chickpea, yellow pea, and white navy bean flours were obtained from commercial supplier as follows: chickpea flour – Brar Natural Flour Mills, Winnipeg, MB; yellow pea flour – Best Cooking Pulses, Portage la Prairie, MB; navy bean flour – Grain Process Enterprises, Scarborough, ON. • Canada Western Amber Durum (CWAD) wheat was roller milled into semolina using the CIGI Bühler pilot mill.

Pasta Processing • Barley flour was substituted for durum semolina at a level of 25%. • Chickpea flour was blended with durum semolina at several levels (10-50%). • Yellow pea flour and navy bean flour were substituted with durum semolina at a level of 30%. • Barley flours blends were mixed (12 min) at a fixed absortion (32%). Spaghetti was processed on the CIGI lab scale pasta press (NAMAD, Rome, Italy). Dough was pressed through a teflon spaghetti die (1.8 mm diameter), and cut by hand to appropriate lengths. The spaghetti strands were dried using a commercial scale Bühler batch dryer (Bühler, Uzwil, Switzerland) using an 85°C drying cycle. • For the pulse flour blends, spaghetti was processed using a commercial scale Bühler Polymatic extrusion press (Uzwil, Switzerland). Water was added to maintain a 80 kPa pressure at the extrusion head. Dough was pressed through a teflon spaghetti die (1.8 mm diameter), and cut by hand to appropriate lengths. Spaghetti was dried using the commercial scale Bühler batch dryer using a 70oC drying cycle.

Analysis of FloursProtein, moisture, ash, β-glucan, starch, and dietary fibre contents were determined on the flours according to AACC standard methods. The results are shown in Table 1 for barley flours.

Analysis of Spaghetti: • Cooking Time: Determined as the time when there was an absence of a white core when a piece of spaghetti was compressed between two Plexiglas plates. • Colour: Lightness (L*), redness (a*) and yellowness (b*) of dried spaghetti was determined using a Minolta CR310 colourimeter (New Jersey, USA). • Cooking Loss: Calculated as the percentage of solids lost by spaghetti during the time to cook to optimum. • Texture: Firmness of the cooked spaghetti was determined using the TAHDi Texture Analyzer using a 25 kg load cell (Stable Micro Systems; Surrey, UK) according to AACC Method 66-50. • Sensory Evaluation: A trained panel rated the samples for firmness, elasticity and flavour intensity using 15 cm unstructured line scales.

RESULTS & DISCUSSION WG Barley Spaghetti • Spaghetti made from the normal starch WG barley flours CDC McGwire and Millhouse had similar cooked texture and cooking losses as the 100% durum semolina spaghetti (Table 2). Spaghetti made from CDC Fibar with zero amylose had significantly softer cooked texture and higher cooking losses suggesting that the waxy starch had a negative impact in this application at the 25% level of substitution. • As expected, all barley spaghetti samples were darker (lower L* values) and less yellow (lower b* values) in colour than the 100% durum control spaghetti due to the added bran components (Figure 1 and Table 2). • All three barley spaghetti delivered 19 g of whole grain per serving and delivered more than 0.75 g β-glucan per serving making them eligible for a β-glucan soluble fibre health claim in the US (Table 2). Given the higher level of β-glucan in CDC Fibar, it may be possible to lower the level of substitution and still achieve a health claim thereby minimizing the negative impact this flour had on spaghetti quality.

Chickpea Flour Spaghetti • The addition of chickpea flour significantly increased the total dietary fibre and protein content of the spaghetti (Table 3). • As chickpea flour content increased, cooking loss increased; instrumental and sensory firmness increased probably because of increased protein content, and elasticity decreased probably because of gluten dilution (Table 3). The flavor intensity also increased with increasing chickpea flour. • With increasing levels of chickpea flour, the spaghetti was darker (lower L* values), less yellow (lower b* values) and had more redness (higher a* values) (Figure 2 and Table 3).

Yellow Pea and Navy Bean Flour Spaghetti • Spaghetti made from yellow pea flour was firmer than spaghetti made from navy bean flour although this characteristic might be explained by the differences in strand diameter. The yellow pea flour spaghetti was 0.1 mm thicker than the navy bean flour spaghetti (1.74 compared to 1.64 mm on average, respectively) suggesting that the yellow pea spaghetti expanded more after extrusion than the bean spaghetti (Table 4). • Firmness of the cooked navy bean spaghetti was comparable to the 100% durum semolina spaghetti, whereas the yellow pea spaghetti was firmer (Table 4). • The yellow pea spaghetti was visually more yellow than the spaghetti made from bean flour (higher b* value), but neither spaghetti was as bright (L* value) as the 100% durum semolina spaghetti (Figure 3 and Table 4). Speckiness was also more pronounced in the yellow pea spaghetti than navy bean spaghetti. • The substitution of durum semolina with either yellow pea or navy bean flour significantly increased the level of total dietary fibre in both spaghetti samples.

CONCLUSIONSThe potential to use WG barley flour and pulse flours in pasta applications shows promise provided that the levels of substitution are reasonable. The use of barley varieties with normal starch contents are recommended. Flavour and textural properties were negatively affected when levels of substitution exceeded 30% for both barley and pulse flours. At levels between 20-30%, it was possible to achieve a significant increase in dietary fibre without seriously affecting the processing and end-product quality.

ACKNOWLEDGMENTSThis work was funded by: • The Advancing Canadian Agriculture and Agri-Food Program, the Alberta Barley Commission, and the Canadian Wheat Board. • The Saskatchewan Pulse Growers, Manitoba Pulse Growers and the Government of Canada. Special thanks to CIGI technology staff (E. Sopiwnyk, K. Pizzi, L. Bourré, G. Boux) and communications staff (A. Medwid).

www.cigi.ca

FIGURE 1. Strands of dried spaghetti made from 100% durum semolina (A), 25% Millhouse (B), 25% CDC McGwire (C), and 25% CDC Fibar (D) barley flours.

TABLE 3. Quality attributes of chickpea spaghetti

Firmness (N) - - Optimum 9.52 8.87 9.78 9.55 10.61 10.25Cooking Loss (%) 5.00 5.38 5.18 5.52 5.99 6.70Brightness (L*) 71.6 70.2 68.1 65.1 63.2 60.9Redness (a*) 1.68 3.67 6.76 10.34 12.82 15.38Yellowness (b*) 59.3 52.1 55.6 53.5 53.3 52.9Sensory Firmnessa 6.3 6.6 7.9 9.2 10 10Sensory Elasticitya 6.7 5.1 2.4 1.5 0.9 0.9Flavour Intensitya 2.2 3.7 4.4 5.8 7.1 7.1Total Dietary Fibre 3.13 3.73 4.34 4.94 5.55 6.15 (g/srvg)baRated on a 15 cm unstructured line scale bFrom Canadian Nutrient File

100% CWAD 10% 20% 30% 40% 50%

FIGURE 2. Colour of cooked spaghetti made with different levels of chickpea flour (C=Control, 100% durum semolina)

FIGURE 3. Strands of dried spaghetti made from 100% durum semolina (A), 30% yellow pea flour (B), and 30% navy bean flour (C).

A B C

TABLE 4. Quality attributes of WG yellow pea and navy bean spaghetti 100% 30% 30% CWAD Yellow Navy Pea BeanFirmness (N) - - Optimum 10.73 11.05 10.58 - Overcooked 6.86 6.44 6.81Brightness (L*) 72.3 69.1 68.2Redness (a*) 2.03 5.50 6.85Yellowness (b*) 57.3 52.0 45.6Total Dietary Fibre (g/srvg)a 3.13 6.68 7.57aFrom Canadian Nutrient File

TABLE 2. Quality attributes of WG barley spaghettia 100% Mill- CDC CDC CWAD house McGwire FibarFirmness (N)- - Optimum 8.56 8.22 7.95 7.01 - Overcooked 5.91 5.93 6.05 4.80Cooking Loss (%) 5.33 5.67 5.83 7.17Brightness (L*) 72.3 63.5 62.3 62.0Redness (a*) 2.03 7.02 7.49 7.84Yellowness (b*) 57.3 44.0 42.1 42.3Whole Grains (g/srvg) 0 19.2 19.2 19.2β-Glucan (g/srvg) 0b 0.79 0.83 1.29Insoluble Dietary Fibre (g/srvg) 3.13b 3.36 3.79 3.76Total Dietary Fibre (g/srvg) 3.13b 4.13 4.13 5.37a25% substitution levelbFrom Canadian Nutrient File

TABLE 1. Analytical data for WG barley flours

Component (%) 100% CWAD Millhouse CDC McGwire CDC Fibar Protein 12.2 12.6 10.6 13.9Ash 0.67 1.51 1.66 1.90Moisture 14.3 10.3 9.5 8.7β-glucan 0.0a 4.1 4.3 6.7Soluble Dietary Fibre 0.0a 4.0 4.7 8.4Insoluble Dietary Fibre 3.9a 5.8 8.0 7.9Total Dietary Fibre 3.9a 9.8 12.7 16.3aFrom Canadian Nutrient File