Accepted Manuscript

Effect of aleurone-rich flour on composition, cooking, textural, and sensory propertiesof pasta

A. Bagdi, F. Szabó, A. Gere, Z. Kókai, L. Sipos, S. Tömösközi

PII: S0023-6438(14)00432-0

DOI: 10.1016/j.lwt.2014.07.001

Reference: YFSTL 4028

To appear in: LWT - Food Science and Technology

Received Date: 5 December 2013

Revised Date: 27 May 2014

Accepted Date: 1 July 2014

Please cite this article as: Bagdi, A, Szabó, F, Gere, A, Kókai, Z, Sipos, L, Tömösközi, S, Effect ofaleurone-rich flour on composition, cooking, textural, and sensory properties of pasta, LWT - FoodScience and Technology (2014), doi: 10.1016/j.lwt.2014.07.001.

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service toour customers we are providing this early version of the manuscript. The manuscript will undergocopyediting, typesetting, and review of the resulting proof before it is published in its final form. Pleasenote that during the production process errors may be discovered which could affect the content, and alllegal disclaimers that apply to the journal pertain.

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

1

EFFECT OF ALEURONE-RICH FLOUR ON COMPOSITION, 1

COOKING, TEXTURAL, AND SENSORY PROPERTIES OF 2

PASTA 3

A Bagdia, F Szabóa, A Gereb, Z Kókaib, L Siposb, S Tömösközia* 4

aDepartment of Applied Biochemistry and Food Science, Budapest University of Technology and 5

Economics, H-1521 Budapest, P.O. Box 91. Hungary 6

bCorvinus University of Budapest, Faculty of Food Science, Sensory Laboratory, 7

H-1118 Budapest, 29-43 Villányi Str., Hungary 8

9

10

Keywords: pasta, aleurone, cooking quality, texture analysis, sensory analysis 11

12

Abbreviations: aleurone-rich flour: ARF, wheat pasta flour: WPF, aleurone-rich flour made pasta: 13

AP, conventional pasta: CP 14

15

*Corresponding author. Tel.: +36 1 463 1419; fax: +36 1 463 3855. Postal address: Budapest 16

University of Technology and Economics, H-1111, 4 Szent Gellért Square, I/106, Budapest, Hungary 17

E-mail address: tomoskozi@mail.bme.hu (S. Tömösközi) 18

19

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

2

20

Abstract 21

The pasta making potential of a recently developed, large-scale produced, wheat aleurone-rich flour 22

(ARF) was examined using a laboratory-scale, dry semolina egg pasta model product. It was 23

confirmed by the outstandingly high protein content (26.67 g/100g d.m.) that ARF is concentrated to a 24

certain degree in aleurone layer and/or in subaleurone cells. The cooked ARF made pasta (AP) had 25

more than two times higher protein (12.72 versus 4.92 g/100g) and ash (1.83 versus 0.71 g/100g) 26

content, greatly higher crude fat (0.52 g/100 g versus 0.0 g/100g) and total dietary fibre (7.76 versus 27

1.70 g/100g) content than the cooked conventional pasta (CP). Addition of ARF to the pasta product 28

resulted in lower water uptake, higher cooked pasta firmness, higher tensile strength, and lower 29

stickiness. The cooking loss of pasta did not change with addition of ARF. Sensory profiling showed 30

darker, more intense, bitterer, and sourer taste of AP compared to CP. Consumer acceptance decreased 31

with addition of ARF regarding texture, flavour, and overall acceptance. Acceptance of AP was 32

significantly higher among assessors, who tend to buy non-conventional pasta products. The results 33

suggest that ARF is more applicable in value-added pasta production than wheat bran fractions or 34

whole-grain flour. 35

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

3

1. Introduction 36

Protective effect of whole-grain consumption against widespread, diet-related diseases is 37

associated with dietary fibre components and phytochemicals of cereals (Fardet, 2010). These 38

components are abundantly present in the germ and in the outer layers of the wheat kernel. Despite 39

their beneficial health effects, the utilization of these grain constituents is hindered because of low 40

consumer acceptance, which is associated with disliked end-product quality (Dammann, Hauge, 41

Rosen, Schroeder, & Marquart, 2013). To preserve the nutritional values several studies have been 42

carried out examining either whole-grain foods or bran reincorporation in food products (Delcour & 43

Poutanen, 2013). 44

One of the ideal fibre-carrier foodstuffs is pasta. Pasta products are staple foods all around the 45

world and have been examined widely regarding fibre enrichment, as reviewed recently (Brennan, 46

2013). Especially much attention has been given to the usage of wheat bran, wheat germ, and wheat 47

wholegrain material in pasta matrices. It has been shown that wheat bran or whole-wheat flour 48

incorporation leads to crucial changes: increased cooking loss (Aravind, Sissons, Egan, & Fellows, 49

2012; Kaur, Sharma, Nagi, & Dar, 2011; Kordonowy & Youngs, 1985; Manthey & Schorno, 2002; 50

Shiau, Wu, & Liu, 2012; Sudha, Rajeswari, & Venkateswara Rao, 2012), decreased water uptake 51

(Aravind et al., 2012; Kordonowy & Youngs, 1985; Sudha et al., 2012), decreased pasta firmness 52

(Aravind et al., 2012; Chen et al., 2011; Kordonowy & Youngs, 1985; Manthey & Schorno, 2002; 53

West, Seetharaman, & Duizer, 2013), and reduced extensibility (Shiau et al., 2012) were reported. 54

Increased cooking loss and decreased firmness refer to lower quality pasta, while water uptake is not 55

unambiguously related to pasta quality in the literature. Furthermore, wheat bran and whole grain 56

addition results in decreased consumer acceptance and leads to a darker product, which has 57

considerably different flavour from conventional pasta (Aravind et al., 2012; Kaur et al., 2011; 58

Kordonowy & Youngs, 1985; West et al., 2013). 59

Besides using wheat bran and whole-grain flour, other possible ways of utilizing the wheat`s 60

nutritional values have emerged. Several fractionation methods have been developed for producing 61

milling fractions that are concentrated in aleurone layer. The aleurone layer is considered to be one of 62

the most valuable parts of wheat, due to its high content of bioactive components (Brouns, Hemery, 63

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

4

Price, & Anson, 2012; Fardet, 2010). Since this layer, anatomically belonging to the endosperm, has 64

considerably different composition from other parts of the wheat bran, it is assumed that aleurone-rich 65

fractions contribute to different functionality than other bran fraction-enriched flour or whole wheat 66

flour. 67

Although several studies address the compositional characterisation of the aleurone layer and 68

aleurone-rich milling fractions, only few studies have been published about aleurone-enriched food 69

products, as reviewed recently (Brouns et al., 2012). These papers showed adverse effects of aleurone-70

rich fraction addition on the end-product quality of bread. However, it was also claimed that the 71

addition of aleurone-rich milling fraction to white flour results in a product that is more acceptable 72

than wholegrain bread while nutritionally comparable to that (Brouns, Adam-Perrot, Atwell, & von 73

Reding, 2010). As these researchers studied exclusively bread products, it is expedient to investigate 74

aleurone enrichment in other types of food matrices, e.g. pasta products. 75

The above mentioned studies worked with laboratory small scale or semi-industrially 76

produced milling fractions. To the knowledge of the authors, no study on industrially produced 77

aleurone-rich milling fraction has been published so far. 78

The objective of the present work was the comprehensive investigation of a newly-developed, 79

industrially produced milling fraction, namely aleurone-rich flour (hereafter: ARF), using a 80

laboratory-scale pasta model product. ARF is produced by adding additional process steps to an 81

existing mill. This process supposedly enriches its product in aleurone layer and/or in subaleurone 82

cells. Compositional traits and rheological properties of ARF have been presented earlier (Tömösközi 83

et al., 2012). While most of the studies that dealt with fibre enrichment of pasta examined dry 84

semolina pasta, in the present study we worked with a dry semolina egg pasta matrix, which is the 85

most widespread type of pasta in Hungary. Compositional, cooking, textural, and sensory evaluation 86

was carried out. 87

88

2. Materials and Methods 89

90

2.1. Materials 91

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

5

WPF and industrially made ARF were provided by Gyermelyi Zrt, Hungary and were produced 92

simultaneously from the same, homogeneous batch of aestivum wheat. WPF meets the requirements 93

of the Codex Alimentarius Hungaricus (Ministry of Agriculture and Rural Development, 2007). ARF 94

producing technology was developed at Gyermelyi Zrt, Hungary with the cooperation of Department 95

of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, 96

Hungary and Bühler AG, Switzerland. Commercially available wheat flour (ash content: 0.55 g/100g), 97

which was used only at particle size distribution measurement, was originated from the same mill. 98

Other ingredients (whole egg powder (protein content: min. 45 g/100 g, fat content: 33±5 g/100 g), 99

salt) were obtained from local shops in Budapest. Samples were stored in sealed plastic pots at room 100

temperature. 101

Mixture of WPF and ARF was prepared in the proportions of 15 g/100 g, 40g/100 g, 75 g/100 g 102

with a Kitchen Aid 5KPM5 planetary mixer (KithcenAid Europa, Inc. Brussels, Belgium) equipped 103

with a flat beater, using a mixing speed of 84 rpm (speed 2) and a mixing time of 8 minutes. 104

105

2.2. Pasta making 106

Flat egg-pasta was prepared from 200 g flour, 4.4 g egg powder, and water. The amount of 107

water used in pasta making was determined during preliminary tests, taking into account the visual 108

appearance and the cohesivity of the cooked and the uncooked pasta. Based on these experiments 70 109

ml water for conventional pasta (CP), and 76 ml for aleurone-rich flour made pasta (AP) was used; 110

linear combination of these amounts was applied for blended samples. The ingredients were mixed 111

and kneaded in a Kitchen Aid 5KPM5 planetary mixer (KithcenAid Europa, Inc. Brussels, Belgium) 112

equipped with a flat beater on a mixing speed of 84 rpm (speed 2). Afterwards 3.5 mm wide flat pasta 113

was prepared in a commercially available pasta press (La Monferrina P3, Asti, Italy) equipped with a 114

dough plate No. 25. The pasta was dried as described elsewhere (Gelencsér, Gál, Hódsági, & Salgó, 115

2007). Dried pasta samples were stored in sealed plastic bags at 4 °C. For determining chemical 116

composition, pasta samples were ground with a Cemotec 1090 Sample mill (Tecator AB, Höganas, 117

Sweden) equipped with a 500 µm sieve and stored in plastic bags until analysis. 118

119

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

6

2.3. Composition and particle size distribution 120

Flour and grounded pasta were analysed for ash, moisture, crude protein (Nx5.7), soluble 121

dietary fibre, insoluble dietary fibre, and total dietary fibre content according to international standards 122

(AACC International, 1999). Crude fibre was determined by Weende method (AOAC, 2003); crude 123

fat was measured by a rapid determination method using hexane (AOAC, 2003). Available 124

carbohydrate content was calculated according to FAO recommendations (FAO, 2003). Measurements 125

were carried out in duplicates. Compositional values of flour are presented in dry basis; data of cooked 126

pasta are reported on the “as-is” basis. 127

Particle size distribution was determined according to AACC method (AACC International, 128

1999), using a Retsch AS 200 vibratory sieve shaker (Retsch Technology GmbH, Haan, Germany) at 129

an amplitude of 70 and with a sieving time of 15 min. Sieves with the following mesh size were used: 130

150 µm, 250 µm, 300 µm. ARF, WPF, and, for comparison, conventional wheat flour (ash: 0.55 g/100 131

g d.m.) was examined. Results are reported on the “as-is” basis. Measurements were carried out in 132

triplicates. 133

134

2.4. Cooking quality 135

For analyses 25 g of dried pasta was cooked in 375 ml water on a hot-plate, adding 3.75 g salt. 136

After cooking, the samples were drained rapidly. Cooking loss and cooking time was determined 137

based on AACC methods (AACC International, 1999). Every sample had a cooking time of 6 138

minutes. For evaluating the water uptake, pasta was weighed before cooking and after draining. Water 139

uptake is the ratio of the weight of the water absorbed during cooking and the weight of dry pasta 140

before cooking (g water/ 100 g pasta). 141

The cooked pasta was freeze-dried in a Christ Alpha 1-4 freeze-dryer (Martin Christ 142

Gefriertrocknungsanlagen GmbH, Osterode am Harz, Germany) right after cooking. The water content 143

of the cooked pasta was determined by an air-oven method (AACC International, 1999). The cooked, 144

freeze-dried pasta was grinded as described above (2.2). All measurements were carried out in 145

duplicates. 146

147

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

7

2.5. Texture analyses 148

Cooked pasta was stored in plastic containers and was subjected to texture analyses, within 15 149

minutes after straining, using a TA TX plus Texture Analyzer equipped with a 5 kg load cell (Stable 150

Microsystem, Surrey, Uk). Exponent 32 6.0.2.0 software was used for recording data. All texture 151

measurements were carried out in quadruplets. Original projects built in the software were loaded and 152

used for the measurements. 153

The project “Comparison of hardness and adhesiveness of noodles using a Cylinder Probe” 154

was used for measuring adhesiveness. The instrument was equipped with a P36 cylinder probe. 155

Default settings were used: 2mm/s pre-test speed, test speed, and post-test speed, 75 % strain, trigger 156

type: 10 g - auto, and 200 pps (points per second) data acquisition. Two stripes of pasta were tested at 157

a time. 158

Pasta firmness was determined with the “Determination of pasta firmness using the AACC 159

(16-50) Standard method” project using a Light Knife Blade probe. Default settings were used: 0.17 160

mm/s test speed, 10 mm/s post-test speed, 4.5 mm distance, trigger type - button, and 400 pps data 161

acquisition. 5 stripes of pasta were placed under the blade perpendicularly to that. 162

Extensibility of pasta was measured using “Extensibility of dough and measure of gluten 163

quality” project. Kiefer dough and gluten extensibility rig was used for the measurement. Default 164

settings were applied: pre-test speed 2 mm/s, 3.3 mm/s, 10 mm/s test speed, and 75 mm distance, 165

trigger force – auto 50g, and 200 pps data acquisition was adjusted. During the test, the sample was 166

extended as long as it broke. Tensile strength and extensibility are reported. One stripe of pasta was 167

placed into the probe at a time. 168

169

2.6. Acceptance tests 170

Acceptance tests were conducted according to ISO/DIS 11136 international standard. An 11 171

points hybrid hedonic scale (0= Disliked extremely, 5= Neither liked nor disliked, 10=liked extremely) 172

was used based on Villanueva and Da Silva (2009). Pasta samples (100 g/person) were tested with 60 173

consumers (recruited at the university; 34 females/26 males; 19–59 years) with respect of appearance, 174

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

8

colour, odour, texture, flavour, and overall acceptance. At the end of the session assessors were asked 175

to record (yes or no) if they regularly buy non-conventional (coloured, value-added products) pasta. 176

177

2.7. Sensory profiling 178

Descriptive profiling (Quantitative Descriptive Analyis, QDA) was carried out in the sensory 179

laboratory of Corvinus University of Budapest, which fulfils the requirements of the ISO8589:2007 180

international standard. Samples were evaluated by a trained panel recruited at the university (6 male/8 181

female). The recommendations of Kilcast (2010) were followed during the sample presentation. 182

In the first phase of the test, the panel developed descriptors for the sensory attributes of CP 183

and AP products. In the final questionnaire a set of 12 descriptive terms was selected (Table 1). For 184

each attribute the panellists created an unstructured line scale with descriptor labels at either ends. The 185

CP was chosen as a reference sample, in order to achieve reduced variation among the panellists. The 186

panel defined the intensity value of the reference sample in respect of every sensory attribute. 187

In the second phase AP was evaluated in comparison to CP. Assessors rated the samples (100 188

g/person) individually, on the basis of the questionnaires, using a balanced test design, in which 189

serving order was randomized for each assessor. Scale responses were converted to numeric values 190

ranging from 0 to 100. The sensory attributes were accepted as variables for statistical evaluation. 191

Special purpose software (ProfiSens, a joint development of the Corvinus University of Budapest and 192

the Budapest University of Technology and Economics) was used during the test sessions to create the 193

experimental design, to collect and to analyse panellists’ data. 194

195

2.8. Statistical analysis 196

Statistical analyses were carried out using Statistica 11 software (StatSoft Inc., Tulsa, 197

Oklahoma, USA). For parametric tests homoscedasticity of the errors, normality, and homogeneity of 198

variance were tested. Where data did not meet the requirements, non-parametric test (Kurskal-wallis) 199

was used. 200

Results of profile analysis were examined with t-test for a single mean. The observed mean of 201

each property of the AP was compared to the corresponding, anchored value of the CP. Simple 202

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

9

regression was used for the analysis of the effects of ARF addition on cooking parameters, texture 203

attributes, and acceptance scores. P-values and adjusted R square values are presented. Difference in 204

acceptance was examined between the two groups with homogeneity-of–slopes model. 5% 205

significance level was used throughout the analyses. Means and 95% confident limits of means are 206

presented. 207

208

3. Results and Discussion 209

3.1. Composition and particle size distribution 210

Great differences in the composition of the flour and in the composition the pasta products 211

were revealed (Table 2). It can be observed that ARF has two times higher protein, four times higher 212

crude fat, total dietary fibre, and greatly higher ash and crude fibre content than WPF. Soluble dietary 213

fibre of ARF proved to be similar to that of WPF. The available carbohydrate content of ARF is lower 214

by 35 g/100g than that of WPF. 215

The high protein content of ARF can originate from the germ, from the aleurone-layer and/or 216

from the subaleurone cells, as these are the anatomical parts of the wheat kernel that possess 217

outstandingly high protein content (Bechtel, Abecassis, Shewry, & Evers, 2009; Brouns et al., 2012) . 218

As the germ is removed in the applied industrial process, we strongly assume that ARF is rich in 219

aleurone layer and/or in subaleurone cells. It has to be noted that the process does not produce entirely 220

concentrated ARF but is optimized according to the manufacturer’s requirements. This can be seen in 221

the dietary fibre content of ARF, which falls short of the dietary fibre content of pure aleurone layer 222

(44-50 g/100g) (Amrein, Gränicher, Arrigoni, & Amadò, 2003). To explore the proportion of different 223

grain tissues in ARF, carrying out biochemical marker analysis (Hemery et al., 2009) would be 224

expedient. 225

Differences in chemical composition between ARF and WPF are mirrored in pasta products as 226

well (Table 2). AP possesses higher protein, crude fat, ash, crude fibre, and total dietary fibre content 227

than CP, while the available carbohydrate content of AP is largely lower than that of CP. Compared to 228

wholemeal spaghetti (FoodStandardAgency, 2002) AP has more than two times higher protein and 229

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

10

dietary fibre content, and 10 g/ 100g lower available carbohydrate content, which refers to a healthier 230

product (Table 2). 231

ARF contains considerably higher amount of particles in the small particle-size region (0-150 232

µm) than WPF (Fig.1). The particle size of ARF is similar to conventional wheat flour; the majority of 233

the particles (about 85 g/ 100g) have a size below 150 µm. The coarse particle-size distribution of 234

WPF is obvious; below 150 µm only 4 g/100g of its particles can be found. 235

236

3.2. Effect of ARF addition on cooking quality 237

Results of cooking experiments are presented on Fig.2. Water uptake decreased significantly 238

(p =0.000, r2=0.92) with growing amount of ARF. This value was 171.1 g water / 100 g pasta at CP, 239

and was 127.1 g water/100 g pasta at AP on average. This tendency is similar to the generally reported 240

effect of wheat bran addition (see 1. Introduction). The physical-chemical background of this 241

phenomenon is probably related to the decreased available carbohydrate (mainly starch) and the 242

increased fibre content. In case of AP high protein and fat content can also play a role (see discussion 243

in 3.6). 244

Pure AP and CP showed 2.12 g/100 g and 2.55 g/100 g cooking loss, respectively. Although 245

these values significantly differ (p=0.001), considering the results of blend flour it can be concluded 246

that ARF addition did not result in obvious increase of this value (p=0.95). This result indicates that 247

ARF addition does not cause poorer pasta quality with respect to cooking loss. It also shows that ARF 248

addition results in better pasta quality than wheat bran or whole wheat flour incorporation, where 249

considerable increase of cooking loss was reported (see 1. Introduction). This difference might be 250

derived from the high protein content, high fat content, and from the carbohydrate composition of 251

ARF (see discussion in 3.6). In addition, in the present paper we added egg powder to pasta, which can 252

also cause different cooking behaviour at fibre addition than it was observed earlier at non-egg-253

containing pasta. 254

255

3.3. Effect of ARF addition on textural properties 256

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

11

All results of texture analyses are presented on Fig.2. Addition of ARF resulted in sharply 257

defined linear increase in cooked pasta firmness (p<0.001; r2=0.81). It is an opposite effect than it was 258

generally reported in case of wheat bran or whole-grain flour addition (see 1. Introduction). We 259

assume that the particular compositional traits, namely high protein, high fat content, and the 260

carbohydrate composition of ARF are primarily responsible for this behaviour (see discussion in 3.6.). 261

Furthermore, egg content of pasta can affect this behaviour as well. It has to be noted that Shiau et al. 262

(2012) also reported increasing cutting force, examining wheat flour made pasta with addition of 263

wheat bran and purified wheat fibre. However, it is unclear whether similar mechanisms, as those 264

operating in our experiments, are responsible for the increase of firmness in their results. 265

Addition of ARF resulted in significant linear increase of adhesiveness values (p<0.00; 266

r2=0.54), that refers to lower stickiness. In case of wheat bran addition Chen et al., (2011) reported 267

similar behaviour. Decreased stickiness might primarily result due to the reduction of available 268

carbohydrates (especially starch), which contributes to lower amount of leaching material. This 269

suggestion is in accordance with the explanation of Aravind et al. (2012). Similarly to firmness, high 270

protein and fat content might also play a key role in decreased stickiness (see discussion in 3.6.). 271

Tensile strength showed significant linear increase (p<0.00; r2=0.35) with growing amount of 272

ARF, while no significant effect (p=0.06) was observed in case of extensibility. This latter result 273

shows that ARF addition to pasta has less negative effect on the formation of gluten network than 274

wheat fibre or wheat bran addition, which causes reduced extensibility (Shiau et al., 2012). 275

276

3.4. Effect of ARF addition on pasta acceptance 277

All results of hybrid hedonic tests meet the requirements of regression models as also indicated by 278

Villanueva & Da Silva (2009). Acceptance scores of pasta are presented on Table3. No significant 279

changes were found in the liking of appearance, colour, and odour (p=0.31, 0.15, 0.69), while liking 280

scores of texture, flavour, and overall acceptance showed significant negative connection (p<0.01; 281

r2=0.02, 0.11, 0.08) with the amount of ARF. All samples were given higher linking scores than 50 in 282

an average, which indicates that assessors judged the AP products to be better than neutral. 283

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

12

The number of assessors who answered that they regularly buy non-conventional pasta is 32; 284

while 28 assessors answered that they never buy non-conventional products. Regarding every property 285

the regression line of "non-conventional pasta buyer" group showed higher slope value than the 286

corresponding regression line of "conventional pasta buyer" group, which refers to higher acceptance 287

of AP. Significant difference in the regression slopes across the groups was found regarding 288

appearance, colour, and overall acceptance (p=0.01, 0.04, 0.04). The effect of the two groups on 289

overall acceptance is illustrated on Fig.3. This result corresponds to the findings of Kordonowy & 290

Youngs, (1985), who presented that higher acceptiblity of bran added pasta is related to brown bread 291

preference. 292

The results of acceptance tests are in accordance with the results of earlier studies, where it 293

was also concluded that pasta acceptance decreased with wheat bran incorporation (Aravind et al., 294

2012; Chen et al., 2011; Kaur et al., 2011; Kordonowy & Youngs, 1985). 295

296

3.5. Sensory profile of pasta products 297

Qualitative differences between the sensory profile of cooked AP and CP were revealed 298

(Fig.4). Significant differences (p<0.001) were found between the two samples in every examined 299

property apart from evenness (p=0.07). AP proved to be darker (browner) and more intense in colour, 300

with lower homogeneity of colour than CP. AP has higher global taste intensity and has significantly 301

more intense bitter and sour taste than CP. From a textural point of view AP is firmer, less extensible, 302

less sticky, and looser during chewing (higher “disintegration during chewing” value) than CP. These 303

results are in accordance with the results of instrumental texture analysis. Both measurements showed 304

that AP is firmer and less sticky (adhesiveness values showed uptrend) than CP. Instrumental 305

extensibility measurement showed that AP is not more extensible in the strict sense but has higher 306

tensile strength than CP. In the author’s opinion this latter property was reflected in sensory profile as 307

low extensiblity. 308

Our results are in accordance with earlier studies (Aravind et al., 2012; West et al., 2013), in 309

which it was concluded that wheat bran addition resulted in darker product that has considerably 310

different flavour. 311

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

13

312

3.6. Relationship between compositional traits of ARF and AP quality 313

In earlier publications it was shown that wheat fibre incorporation resulted in low pasta quality 314

compared to conventionally consumed pasta: decreased firmness and higher cooking loss was 315

reported. These properties are generally explained with bran particles disrupting the gluten matrix 316

(Aravind et al., 2012; Manthey & Schorno, 2002). AP showed opposite behaviour in these respects 317

(higher firmness and not increasing cooking loss), although it contains high amount of fibre. This 318

indicates that other factors compensated the adverse effects of fibre inclusion. We suppose that the 319

particular composition of ARF is primarily associated with this phenomenon. Hereinafter we look 320

through the properties of ARF that could contribute to the observed behaviour. 321

High protein content (26.67 g/100 g) of ARF is the most crucial difference between the 322

composition of ARF and wheat bran fraction or whole-grain flour. Based on the results of earlier 323

studies we assume that high protein content is responsible for higher firmness (Del Nobile, Baiano, 324

Conte, & Mocci, 2005; Petitot, Boyer, Minier, & Micard, 2010; Sissons, Egan, & Gianibelli, 2005) 325

and lower stickiness (Del Nobile et al., 2005; Sissons et al., 2005) of AP compared to CP. High 326

protein content might also be related to lower water uptake (Petitot et al., 2010) and might also have 327

an influence on cooking loss (Malcolmson, Matsuo, & Balshaw, 1993). Besides, protein profile of the 328

aleurone layer probably also has an importance in the functionality of ARF. During conventional 329

milling aleurone-specific non-gluten proteins (proteins involved in metabolism, defence enzymes, 330

inhibitors, globulin-like proteins) (Jerkovic et al., 2010) are removed and therefore are not important 331

in determining quality properties (Lafiandra et al., 2012). Since ARF is likely to be enriched in 332

aleurone layer (see 3.1) these proteins might have a relevant role in the quality of AP. The end-333

product-related effects of these proteins have not been studied yet. 334

In addition to the protein profile, the carbohydrate composition of ARF can also play an 335

important role in the behaviour of AP (Tömösközi et al., 2012). While other parts of the bran consist 336

of large quantities of cellulose, the main carbohydrates of the aleurone layer are pentosans, mostly 337

arabinoxylans (Brouns et al., 2010). This difference can result in dissimilar behaviour between ARF 338

and other high-fibre containing milling products, since arabinoxylans are more reactive dough 339

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

14

constituents than cellulose: arabinoxylans are known to affect the rheological properties of wheat 340

dough (Lafiandra et al., 2012) by means of interacting with the gluten system through ferulic-acid 341

monomers (Noort, van Haaster, Hemery, Schols, & Hamer, 2010). 342

Based on earlier studies (Aravind et al., 2012; Grant, Dick, & Shelton, 1993; Matsuo, Dexter, 343

Boudreau, & Daun, 1986) it can be supposed, that the relatively high crude fat content (4.26 g/100 g) 344

of ARF contributes to higher firmness, lower stickiness, and not increasing cooking loss of AP 345

compared to CP. The presumed theory behind this phenomenon is that high amount of fat material 346

reduces starch granule disruption by means of binding to the granules, ensuring a firm starch gel in the 347

pasta and so resulting in a firmer product. Furthermore, reduced starch granule disruption might also 348

lead to a reduction of solid material leaching, in this manner contributing to lower cooking loss and 349

stickiness (Aravind et al., 2012). That in case of ARF we measured considerably higher crude fat 350

content than in case of AP (Table2) shows that remarkable lipid binding occurred during pasta 351

processing. This theory could be confirmed by further investigation of fat content, with particular 352

respect to bound lipids. Furthermore, high fat content of ARF might also contribute to lower water 353

uptake, as Grant et al. (1993) found that added lipid components, namely monoglycerides, resulted in 354

decreased cooked weight. The hydrophobic properties of lipid components might also play a role in 355

this behaviour. 356

Another essential aspect can be the fine particle size of ARF. It probably also be of importance 357

in the increasing firmness and reduced stickiness through enhancing the binding of available amylose 358

(Chen et al., 2011; Grant et al., 1993). 359

360

4. Conclusions 361

ARF is promising in value-added food production due to its high dietary fibre content. Although 362

consumer acceptance decreased with ARF addition, cooking and textural characterisation of pasta 363

showed that ARF addition does not lead to poor quality characteristics that are generally observed in 364

case of fibre addition. According to our assumptions this behaviour is caused by the particular 365

properties of ARF: high protein content, high fat content, and fine particle size of ARF might 366

contribute to processes that compensate the negative effects of fibre incorporation. The protein profile 367

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

15

and carbohydrate composition of the aleurone layer can also have importance. Based on these results 368

we suppose that ARF is more applicable in value-added pasta production than wheat bran fractions or 369

whole-grain flour. These deductions need confirmatory studies, especially working with other pasta 370

types and with other pasta making procedures. 371

372

5. Acknowledgements 373

This work is connected to the scientific projects of "Health Promotion and Tradition: Development of 374

raw materials, functional foods and technologies in cereal-based food chain" (TECH_08_A3/2-2008-375

0425) and "Development of quality oriented, harmonized educational and R+D+I strategy and 376

operational model at the Budapest University of Technology and Economics" (TÁMOP-4.2.1/B-377

09/1/KMR-2010-0002)". 378

References 379

AACC International. (1999). Approved Methods of Analysis (Methods 44-15.02, 08-01.01, 46-30.01, 380

32-07.01, 66-20.01, 66-50.01) (11th ed.). St. Paul, Minnesota, USA: AACC International, Inc. 381

Amrein, T. M., Gränicher, P., Arrigoni, E., & Amadò, R. (2003). In vitro digestibility and colonic 382

fermentability of aleurone isolated from wheat bran. LWT - Food Science and Technology, 36(4), 383

451–460. doi:10.1016/S0023-6438(03)00036-7 384

AOAC. (2003). Official Methods of Analysis (AOAC 2003.06, AOAC 978.10) (17th ed.). Arlington, 385

Virginia, USA: AOAC International. 386

Aravind, N., Sissons, M., Egan, N., & Fellows, C. (2012). Effect of insoluble dietary fibre addition on 387

technological, sensory, and structural properties of durum wheat spaghetti. Food Chemistry, 388

130(2), 299–309. Retrieved from 389

http://linkinghub.elsevier.com/retrieve/pii/S030881461101003X 390

Bechtel, D. B., Abecassis, J., Shewry, P. R., & Evers, A. D. (2009). CHAPTER 3: Development, 391

Structure, and Mechanical Properties of the Wheat Grain. In WHEAT: Chemistry and 392

Technology, Fourth Edition (pp. 51–95). AACC International, Inc. 393

doi:doi:10.1094/9781891127557.003 394

Brennan, C. . (2013). Fibre-enriched and wholegrain pasta. In J. A. Delcour & K. Poutanen (Eds.), 395

Fibre-Rich and Wholegrain Foods: Improving Quality (pp. 273–286). Cambridge: Woodhead 396

Publishing Limited. 397

Brouns, F., Adam-Perrot, A., Atwell, B., & von Reding, W. (2010). Nutritional and technological 398

aspects of wheat aleurone fibre: implications for use in food. In J. W. van der Kamp, J. Jones, B. 399

McCleary, & D. Topping (Eds.), Dietary fibre: new frontiers for food and health (1st ed., pp. 400

395–413). Wageningen: Wageningen Academic Publishers. 401

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

16

Brouns, F., Hemery, Y., Price, R., & Anson, N. M. (2012). Wheat aleurone: separation, composition, 402

health aspects, and potential food use. Critical Reviews in Food Science and Nutrition, 52(6), 403

553–68. doi:10.1080/10408398.2011.589540 404

Chen, J. S., Fei, M. J., Shi, C. L., Tian, J. C., Sun, C. L., Zhang, H., … Dong, H. X. (2011). Effect of 405

particle size and addition level of wheat bran on quality of dry white Chinese noodles. Journal of 406

Cereal Science, 53(2), 217–224. doi:10.1016/j.jcs.2010.12.005 407

Dammann, K. W., Hauge, D., Rosen, R. A., Schroeder, N., & Marquart, L. (2013). Consumption and 408

consumer challenges of wholegrain foods. In J. A. Delcour & K. Poutanen (Eds.), Fibre- rich 409

and wholegrain foods (1st ed., pp. 130–131). Cambridge: Woodhead Publishing Limited. 410

doi:10.1533/9780857095787.1.120 411

Del Nobile, M. a., Baiano, a., Conte, a., & Mocci, G. (2005). Influence of protein content on spaghetti 412

cooking quality. Journal of Cereal Science, 41(3), 347–356. doi:10.1016/j.jcs.2004.12.003 413

Delcour, J. a., & Poutanen, K. (Eds.). (2013). Fibre-Rich and Wholegrain Foods: Improving Quality. 414

Cambridge: Woodhead Publishing Limited. 415

FAO. (2003). Food energy – methods of analysis and conversion factors (p. 13). Rome: FAO. 416

Retrieved from http://www.fao.org/docrep/006/y5022e/y5022e00.htm 417

Fardet, A. (2010). New hypotheses for the health-protective mechanisms of whole-grain cereals: what 418

is beyond fibre? Nutrition Research Reviews, 23(1), 65–134. doi:10.1017/S0954422410000041 419

FoodStandardAgency. (2002). McCance and Widdowson’s The Composition of Foods (6th ed.). 420

Cambridge: Royal Society of Chemistry. doi:10.1039/9781849735551 421

Gelencsér, T., Gál, V., Hódsági, M., & Salgó, A. (2007). Evaluation of Quality and Digestibility 422

Characteristics of Resistant Starch-Enriched Pasta. Food and Bioprocess Technology, 1(2), 171–423

179. doi:10.1007/s11947-007-0040-z 424

Grant, L. A., Dick, J. W., & Shelton, D. R. (1993). Effects of drying temperature, starch damage 425

sprouting, and additives on spaghetti quality characteristics. Cereal, 70(6), 676–684. 426

Hemery, Y., Lullien-Pellerin, V., Rouau, X., Abecassis, J., Samson, M.-F., Åman, P., … Barron, C. 427

(2009). Biochemical markers: Efficient tools for the assessment of wheat grain tissue proportions 428

in milling fractions. Journal of Cereal Science, 49(1), 55–64. doi:10.1016/j.jcs.2008.07.006 429

Jerkovic, A., Kriegel, A. M., Bradner, J. R., Atwell, B. J., Roberts, T. H., & Willows, R. D. (2010). 430

Strategic distribution of protective proteins within bran layers of wheat protects the nutrient-rich 431

endosperm. Plant Physiology, 152(3), 1459–70. doi:10.1104/pp.109.149864 432

Kaur, G., Sharma, S., Nagi, H. P. S., & Dar, B. N. (2011). Functional properties of pasta enriched with 433

variable cereal brans. Journal of Food Science and Technology, 49(4), 467–474. 434

doi:10.1007/s13197-011-0294-3 435

Kilcast, D. (2010). Sensory analysis for food and beverage quality control: A practical guide. In D. 436

Kilcast (Ed.), Sensory analysis for food and beverage quality control (pp. 156–184). Woodhead 437

Publishing Limited. Retrieved from 438

http://www.woodheadpublishing.com/en/book.aspx?bookID=1519 439

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

17

Kordonowy, R., & Youngs, V. (1985). Utilization of durum bran and its effect on spaghetti. Cereal 440

Chem. Retrieved from 441

http://www.aaccnet.org/publications/cc/backissues/1985/Documents/chem62_301.pdf 442

Lafiandra, D., Masci, S., Sissons, M., Dornez, E., Delcour, J. A., Courtin, C. M., & Caboni, M. F. 443

(2012). Kernel Components of Technological Value. In M. Sissons, J. Abecassis, B. Marchylo, 444

& M. Carcea (Eds.), Durum Wheat Chemistry and Technology (2nd ed., pp. 86, 102). St. Paul, 445

Minnesota: AACC International, Inc. 446

Malcolmson, L., Matsuo, R., & Balshaw, R. (1993). Textural optimization of spaghetti using response 447

surface methodology: Effects of drying temperature and durum protein level. Cereal Chemistry, 448

70(4), 417–423. Retrieved from http://agris.fao.org/agris-449

search/search/display.do?f=1994/US/US94240.xml;US9434176 450

Manthey, F. A., & Schorno, A. L. (2002). Physical and Cooking Quality of Spaghetti Made from 451

Whole Wheat Durum. Cereal Chemistry, 79(4), 504–510. Retrieved from 452

http://cerealchemistry.aaccnet.org/doi/abs/10.1094/CCHEM.2002.79.4.504?journalCode=cchem 453

Matsuo, R., Dexter, J., Boudreau, A., & Daun, J. (1986). The role of lipids in determining spaghetti 454

cooking quality. Cereal Chem, (September 1985). Retrieved from 455

http://www.aaccnet.org/publications/cc/backissues/1986/Documents/Chem63_484.pdf 456

Ministry of Agriculture and Rural Development. (2007). Products of the Milling Industry, 2-61 457

Directive. In Codex Alimentarius Hungaricus (3rd ed., pp. 4–6). Hungary. 458

Noort, M. W. J., van Haaster, D., Hemery, Y., Schols, H. a., & Hamer, R. J. (2010). The effect of 459

particle size of wheat bran fractions on bread quality – Evidence for fibre–protein interactions. 460

Journal of Cereal Science, 52(1), 59–64. doi:10.1016/j.jcs.2010.03.003 461

Petitot, M., Boyer, L., Minier, C., & Micard, V. (2010). Fortification of pasta with split pea and faba 462

bean flours: Pasta processing and quality evaluation. Food Research International, 43(2), 634–463

641. doi:10.1016/j.foodres.2009.07.020 464

Shiau, S.-Y., Wu, T.-T., & Liu, Y.-L. (2012). Effect of the Amount and Particle Size of Wheat Fiber 465

on Textural and Rheological Properties of Raw, Dried and Cooked Noodles. Journal of Food 466

Quality, 35(3), 207–216. doi:10.1111/j.1745-4557.2012.00436.x 467

Sissons, M. J., Egan, N. E., & Gianibelli, M. C. (2005). New Insights Into the Role of Gluten on 468

Durum Pasta Quality Using Reconstitution Method. Cereal Chemistry, 82(5), 601–608. 469

Retrieved from http://europepmc.org/abstract/AGR/IND43749670/reload=0 470

Sudha, M. L., Rajeswari, G., & Venkateswara Rao, G. (2012). Effect of Wheat and Oat Brans on the 471

Dough Rheological and Quality Characteristics of Instant Vermicelli. Journal of Texture Studies, 472

43(3), 195–202. doi:10.1111/j.1745-4603.2011.00329.x 473

Tömösközi, S., Szendi, S., Bagdi, A., Harasztos, A., Bucsella, B., Balázs, G., & Csiki, Z. (2012). 474

Characterization of Novel Wheat Fractions Reach in Dietary Fiber: Composition, Rheology and 475

End-Product Quality. In W. X. Yu Yanxia, Meng Yongcheng, Zong Yingjun, Liu Boao, Li Fang 476

(Ed.), Proceedings of 14th ICC Cereal and Bread Congress and Forum on Fats & Oils, August 477

6-9, 2012, Beijing, China (p. 34). Bejing, China: ICC. 478

Villanueva, N. D. M., & Da Silva, M. a. a. P. (2009). Comparative performance of the nine-point 479

hedonic, hybrid and self-adjusting scales in the generation of internal preference maps. Food 480

Quality and Preference, 20(1), 1–12. doi:10.1016/j.foodqual.2008.06.003 481

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

18

West, R., Seetharaman, K., & Duizer, L. M. (2013). Effect of drying profile and whole grain content 482

on flavour and texture of pasta. Journal of Cereal Science. doi:10.1016/j.jcs.2013.03.018 483

484

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

19

Tables 485

486

Table1 Attributes and descriptive terms of profile analysis of AP (aleurone-rich flour made pasta), and CP (conventional pasta).

Attribute Weak end point Intense end point appearance hue white brown homogeneity of colour heterogenic homogeneous evenness wavy even colour intensity weak intense odour bitter odour weak intense texture firmness elastic firm extensibility poorly extensible very extensible disintegration during chewing cohere loose stickiness not sticky very sticky taste global taste intensity weak intense bitter taste intensity weak intense sour taste intensity weak intense

487

488

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

20

Table2

Composition of WPF (wheat pasta flour), ARF (aleurone-rich flour), CP (conventional pasta), AP (aleurone-rich flour made pasta), and literary data of wholemeal spaghetti. Means of duplicate measurements and 95% confidence interval of means are presented.

WPF

(g/100g) ARF (g/100g)

CP, cooked (g/100 g portion)

AP, cooked (g/100 g portion)

Wholemeal spaghettia

(g/100g)

Water - - 68.2 62.9 69.1

Protein 13.04 ± 0.14 26.67 ± 0.18 4.92 ± 0.01 12.72 ± 0.05 4.7

Crude fat 0.36 ± 0.02 4.26 ± 0.09 0.0 0.52 ± 0.04 0.9

Crude fibre 0.22 ± 0.06 5.04 ± 0.29 0.11 ± 0.02 2.18 ± 0.42 n.a.*

Ash 0.22 ± 0.05 3.83 ± 0.03 0.71 ± 0.06 1.83 ± 0.01 n.a.*

Total dietary fibre 3.77 ± 0.15 17.59 ± 0.51 1.70 ± 0.06 7.76 ± 0.58 3.5

Soluble dietary fibre

1.40 ± 0.01 1.42 ±.0.93 0.54 ± 0.03 1.09 ± 0.10 n.a.*

Insoluble dietary fibre

2.37 ± 0.14 16.17 ± 0.42 1.16 ± 0.04 6.67 ± 0.08 n.a.*

Available carbohydrate**

82.6 47.65 24.47 13.59 23.2 aFoodStandardAgency 2002, *not available, **calculated

489

490

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

21

491

Table3 Effect of ARF (aleurone-rich flour) addition on pasta acceptance regarding different properties. Means of 60 tests and 95 % confidence interval of means are presented. ARF content

(g/100 g) Appearance Colour Odour Texture* Flavour*

Overall acceptance*

0 76,3 ± 7.9 77,4 ± 8.2 70,3 ± 8.4 75,6 ± 8.0 85,8 ± 6.7 79,3 ± 7.6

15 74,8 ± 6.3 77,9 ± 6.6 76,2 ± 6.4 79,4 ± 6.5 80,8 ± 5.6 79,1 ± 6.5

40 75,9 ± 5.0 76,6 ± 5.2 75,2 ± 6.8 71,9 ± 6.2 74,8 ± 6.5 70,6 ± 7.5

75 71,3 ± 6.3 71,8 ± 6.8 74,5 ± 7.5 68,3 ± 7.6 62,8 ± 7.7 59,6 ± 8.3

100 73,2 ± 6.1 73,2 ± 6.9 74,2 ± 7.8 66,8 ± 7.2 61,7 ± 7.7 59,8 ± 8.0

*significant effect of ARF addition (p<0.05)

492

493

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

22

Figure captions 494

Fig.1. Particle size distribution of ARF (aleurone-rich flour) ( ), WPF (wheat pasta flour) (495

) and wheat flour ( ). Means of triplicates and 95 % confidence interval of means are 496

presented. 497

Fig.2. Effect of ARF (aleurone-rich flour) addition on water uptake, cooking loss, firmness, 498

adhesiveness, tensile strength, and extensibility of pasta. Means of quadruplets, 95 % 499

confidence interval of means, and linear regression lines are presented. 500

Fig.3. Effect of ARF (aleurone-rich flour) addition on overall acceptance of pasta regarding 501

“non-conventional pasta buyer” ( ) and “conventional pasta buyer” ( ) consumer groups. 502

Means and 95% confidence interval of means, and linear regression lines are presented. 503

Fig.4. Sensory profile of AP (aleurone-rich flour made pasta) ( ) and CP (conventional 504

pasta) ( ). Means of 12 tests are presented. 505

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

23

Figures 506

Fig. 1. 507

508

509

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

24

Fig.2. 510

511

512

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

25

Fig.3. 513

514

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

26

Fig.4. 515

516

MANUSCRIP

T

ACCEPTED

ACCEPTED MANUSCRIPT

EFFECT OF ALEURONE-RICH FLOUR ON COMPOSITION,

COOKING, TEXTURAL AND SENSORY PROPERTIES OF

PASTA - HIGHLIGHTS

• The major chemical composition of an aleurone-rich flour made pasta is presented • We confirm that the basic material is concentrated in wheat aleurone layer • Cooking and textural properties of aleurone-rich flour made pasta is reported • Results of sensory profiling and acceptance tests are presented and explained

• Pasta properties are explained with compositional traits of aleurone-rich flour