INSTRUMENTAL AND SENSORY PROPERTIES OF BUCKWHEAT FLOUR PASTA

DOI:

UDK:

JOURNAL No:

Volume 38, Issue 2

PAGES

45-50

KEYWORDS

sensory properties, pasta, buckwheat flour, cooking quality, colour determination

TOOLS

Dubravka J. Jambrec*¹, Mladenka V. Pestorić¹, Đorđe B. Psodorov¹, Marijana B. Sakač¹,

Nataša M. Nedeljković¹, Anamarija I. Mandić¹, Ivana J. Sedej¹

¹University of Novi Sad, Institute of Food Technology, Bulevar cara Lazara 1,

21000 Novi Sad, Serbia

ABSTRACT

The standard wholegrain wheat flour pasta formulation was modified using light buckwheat flour at the level of 20% to obtain a new added-value product. The control and enriched dry pasta were tested on chemical and colour properties. Cooking properties were also investigated in the pasta samples. Sensorial properties for dry and cooked pasta were evaluated using the 5-point category scale.
The obtained results suggest that the substitution of wheat with buckwheat flour in the formulation of pasta did not influence tested parameters remarkably.

INTRODUCTION

Consumers' attention in recent years has been directed to nutritional and health as-pects of foods. The application of new ingre-dients in the basic product formulation could result in products with higher nutritional value and new sensory quality (Šimurina et al. 2009). Pasta and pasta related products are known as frequently used food in human nutrition on a daily basis (Plavšić et al., 2010). According to UN. A. F. P. A from 2009 (http://www.pasta-unafpa.org), pasta con-sumption was over 3 million tonnes in the E. U., and tends to increase. Therefore, pasta is recognised as good matrix for supplemen-tation with various health beneficial supple-ments.

Buckwheat (Fagopyrum esculentum Moench) possesses a great potential for upgrading the functional properties of foods due to its high content of proteins, starch, and vitamins. Mo-reover, buckwheat has been reported to po-ssess higher antioxidant activity than the most frequently used cereals (Kreft et al. 2006). High phenolics content, especially ru-tin, contributes to the increased functionality of foods. Buckwheat does not contain gluten and therefore is convenient for gluten-free products (Sedej et al. 2011; Torbica et al. 2010).

The substitution of wheat flour in commonly used pasta with buckwheat flour can fortify pasta with proteins, dietary fibres, vitamins and minerals with acceptable effects on sen-sory and cooking quality (Schoenlechner et al. 2010).

In order to found new nutritionally perspective pasta recipe, the replacement of 20% whole-grain wheat flour with light buckwheat flour in pasta formulation was studied with the aim to determine the effect of buckwheat addition on pasta cooking quality, colour and sensory properties.

MATHERIALS AND METHODS

Samples

The standard formulation of wholegrain wheat flour pasta was modified by substitution of wheat flour with 20% of light buckwheat flour. The pasta (tagliatella shape) was produced by using Ital past Mac 60 (Parma, Italy).

Pasta cooking quality

Optimal cooking time (OCT) was determined as the time necessary to disappear white core in the middle of the pasta sample when it was pressed between two transparent plastic tiles. Pasta samples were cooked in boiling water (1000 mL) containing 0.5% (w/v) of sodium chloride.
Dry matter content of cooked pasta was de-termined by using a blend of water from cooking and rinsing pasta sample which was evaporated and dried 90 minutes at 130 °C. The residue was weighted and reported as a percentage of the dry matter of dry pasta sample.
The volume increase (VI) was determined as the ratio between volume of cooked and un-cooked pasta sample.
Cooking loss (CL) (the amount of solid sub-stance lost to cooking water) and the above parameters of cooking quality were deter-mined according to natural regulation (Pra-vilnik o metodama fizičkih i hemijskih analiza žita, mlinskih i pekarskih proizvoda, testenina i brzo smrznutih testa (“Sl. list SFRJ”, br. 74/88)).

Colour determination

The colour of dry pasta samples was measu-red using a Minolta Chromameter (Model CR-400, Minolta Co., Osaka, Japan), with gra-nular attachment CR-A50, and expressed in Commission Internationale d’ Eclairage L* (lightness), a* (redness-greenness), b* (ye-llowness-blueness) colour-space. Prior to co-lour measurements dry pasta samples were grounded in 1095 Knifetec sample mill.

Sensory evaluation

A panel of five assessors with experience in sensory analysis of pasta (4 females and 1 male, 30-43 years old) were selected and recruited from the Institute of Food Tech-nology, Novi Sad, holding weekly sessions for the purpose according to ISO 8586-2 (1994).
The initial training stage of assessors invol-ved introducing the method to assessors, and training using the real products-control sam-ples. Six sessions were performed lasting about two hours each. The first three se-ssions were introduction to the sensory pro-perties of wholemeal pasta during which the assessors were introduced to the definition of terms to be used. The remaining sessions corresponded to the evaluation of control samples used in the further study.
Sensory properties of dry and cooked pasta were evaluated by the 5-point category scale with end-points labelled from 1 to 5 as shown in Table 1 (Pestorić, 2007; Pestorić et al. 2010; Pestorić, 2011). All properties were evaluated visually, palpatory, olfactory and gustatory under laboratory condition that ful-filled requirements of ISO 8589 (2007).
All samples were identified with three random numbers and samples were presented in completely randomised order among asse-ssors. At the start of each session assessors were given a printed response sheet with written instructions for the tests.
Dry pasta samples were presented on the plastic plates, while cooked pasta samples were presented in thermal plastic cups and served at room temperature within 20 mi-nutes after cooking. Plain water was used for mouth rinsing before and after each sample testing. Statistical analysis Results were expressed as mean ± standard deviation of triplicate analyses for all mea-surements, except the colour determinationof the samples which was performed in ten repetitions.
Analysis of variance and Duncan's multiple range test were used to compare means at 5% significance level by using statistical data analysis software systemSTATISTICA (Stat-Soft, Inc. (2008) data analysis software sys-tem, version 10.0. www.statsoft.com).

Table 1.Scoring method for dry and cooked pasta

Sensory evaluation of dry pasta
Visualy
Shape	Colour	Colour uniformity
5 – Appropriate with no damage 4 – Insignificant deviation of shape 3 – Noticeable deficiencies 2 – Clearly noticeable deficiencies 1 – Highly noticeable deficiencies	Hue: 5 – Brown 4 – Slight differences* 3 – Noticeable differences* 2 – Clearly noticeable differences* 1 – Highly noticeable differences* *indicate a differences (differences refers to the lighter and darker shade with regard to the standard S4020-Y40R)	5 – Uniform 4 – Almost uniform 3 – Slightly uniform 2 – Non-uniform 1 – Highly non-uniform
Palpatory
Fracturability
5 – Excellent resistance to fracture 4 – Very good resistance to fracture 3 – Good resistance to fracture 2 – Poor resistance to fracture 1 – Extremely poor resistance to fracture

Sensory evaluation of cooked pasta
Olfactory
Odour
5 – Appropriate odour, rounded, aromatic 4 – Appropriate odour, less rounded, aromatic 3 – Appropriate odour, less rounded, less aromatic 2 – Inappropriate odour, presence of foreign odour 1 – Foreign odour, unpleasant
Palpatory
Firmness	Liveliness		Elasticity	Surface adhesiveness
5 – Excellent firmness 4 – Very good firmness 3 – Good firmness 2 – Poor firmness 1 – Extremely poor firmness	5 – Excellent liveliness 4 – Very good liveliness 3 – Good liveliness 2 – Poor liveliness 1 – Extremely poor liveliness		5 – Excellent elasticity 4 – Very good elasticity 3 – Good elasticity 2 – Poor elasticity 1 – Extremely poor elasticity	5 – Not sticky 4 – Insignificantly sticky 3 – Slightly sticky 2 – Sticky 1 – Extremely sticky
Gustatory
Chewiness		Granularity	Taste
5 – Excellent chewiness 4 – Very good chewiness 3 – Good chewiness 2 – Poor chewiness 1 – Extremely poor chewiness		5 – Excellent granularity 4 – Very good granularity 3 – Good granularity 2 – Poor granularity 1 – Extremely poor granularity	5 – Appropriate taste, rounded, aromatic 4 – Appropriate taste, less rounded, aromatic 3 – Appropriate taste, less rounded, less aromatic 2 – Inappropriate taste, presence of foreign taste 1 – Foreign taste, unpleasant

RESULTS AND DISCUSSION

Chemical analysis and cooking properties of pasta

Table 2 summarizes the results of chemical analysis of dry pasta and cooking properties of pasta. The pasta samples had similar moi-sture content but different contents of other chemical parameters. Except starch, the con-tent of other determined parameters was higher in the sample B because of the known structure differences between buckwheat and wheat grains (Steadman et al. 2001; Bona-faccia et al. 2003; Skrabanja et al. 2004).
The optimal cooking time for the pasta with-out buckwheat flour was longer than for the pasta with added 20% light buckwheat flour. This was in accordance with Chillo et al. (2008) and Manthey et al. (2004) who sho-wed that the addition of buckwheat flour up to 30% caused a decrease in optimal cooking time of pasta. The same authors explained this phenomenon by physical disruption of the gluten matrix and overall low density that provides a path for water absorption into pas-ta containing buckwheat flour which results in a shorter cooking time.
The pasta with added buckwheat flour had cooking loss value quite lower than that of the wheat pasta indicating it has acceptable coo-king loss level.

Colour determination

Pasta colour is essential for assessing pasta quality. Generally, pasta consumers prefer pasta with a bright yellow colour (Debbouz et al. 1995). Flours that were used for the pro-duction of all tested pasta showed beige co-lour (L* values were in the range of 82.05-83.49), which contributed to darker coloura-tion of the final products (data not shown). Brown colour might be noticeable to attract consumers’ attention on these products, be-cause consumer normally associates the pasta rich in dietary fibre to a darker colour (Chillo et al. 2008). Table 3 shows the L*, a* and b* values for pasta samples.
Decrease in pasta colour with regard to flour type was noticed. This may be related to the development of Maillard reaction products which readily occurs during pasta drying (Anese at al. 1999). Significant differences (P < 0.05) were detected on lightness (L*) and redness (a*) among the pasta samples. Buck-wheat addition led to a decrease of L* and a* parameters (B sample was darker and less red than the sample A), but did not signi-ficantly affect b*. Colour scores have been calculated as (L* + (b* x 2))/20, giving a score range of 1-10, with 10 being the best qualification (Hareland et al. 1995). The calculated colour scores are shown in Table 3. The sample B had negli-gible lower value of colour score. Both pasta samples expressed the acceptable colour scores which were at the same level as durum pasta (Martinez et al. 2007).

Table 2. Chemical characteristics of dry pasta and cooking properties of pasta

	Chemical analysis					Cooking properties
Sam- ple	Mois- ture (% d.b.)	Pro- tein (% d.b.)	Ash (% d.b.)	Cellu- lose (% d.b.)	Starch (% d.b.)	OCT (min)	CL (% d.b.)	VI (%)
A	11.35±0.03	11.60±0.10	1.30±0.03	0.44±0.01	66.42±0.16	9.00±0.30	10.33±0.40	2.86±0.20
B	11.09±0.01	13.42±0.07	1.59±0.02	0.88±0.02	60.47±0.01	8.00±0.10	7.83±0.60	3.07±0.40

Abbreviations used in table: OCT– optimal cooking time; CL – cooking loss; VI –volume increase.
Values are means of three determinations ± standard deviation.

Table 3. Dry pasta colour measurements

Sample	L*	a*	b*	Colour scores (1-10)
A	75.29 ± 0.45b	2.91 ± 0.17b	14.77 ± 0.11a	5.24
B	74.67 ± 0.45a	2.61 ± 0.12a	14.73 ± 0.32a	5.21

Values are means of ten determinations ± standard deviation.
Values followed by a different letter within a column are significantly different (P < 0.05).
Colour scores: (L* + (b* x 2))/20; score range: 1-10, with 10 being the best qualification.

Sensory evaluation

Table 4. Sensory evaluation of pasta

	Dry samples
	Shape		Uniformity of colour			Colour			Brittleness
A	4.00±0.67a		4.40±0.52a			4.40±0.52a			3.90±0.88a
B	4.00±0.67a		4.40±0.70a			4.70±0.48a			4.30±0.67a
	Cooked samples
	Odour	Firmness		Liveliness	Elasticity	Surface stickiness	Chewiness	Granularity		Taste
A	4.70±0.48a	4.50±0.53a		3.90±0.74a	3.30±0.67a	3.90±0.57a	3.70±0.67a	4.00±0.67a		4.10±0.88a
B	5.00±0.00a	4.30±0.67a		4.00±0.67a	4.00±0.67b	3.60±0.52a	4.30±0.67a	4.30±0.82a		4.60±0.52a

Values are means ± standard deviation of five panelists.
Values with the different superscript within a column are statistically different (P < 0.05).

Results of sensory evaluation of pasta sam-ples are presented in Table 4. Quality cate-gory was determined in dependence of sco-res: unacceptable (< 2.5), good (2.5-3.5), very good (3.5-4.5) and excellent (> 4.5).
On the 5-point category scale, sensory re-sults for the dried pasta were in the range of 3.90-4.70 indicating very good and excellent sensory quality. Scores for cooked pasta samples were in the range of 3.30-5.00. Duncan's multiple range test of dried pasta samples showed that addition of light buck-wheat flour did not significantly (P < 0.05) affect the sensory properties, except the ela-sticity of cooked pasta. However, it should be noted that the addition had an impact on improving scores of colour and brittleness of buckwheat pasta. In general, the results ob-tained for the cooked pasta indicate that buckwheat flour addition led to an increase in sensory quality.

CONCLUSION

Wholegrain wheat pasta supplemented with 20% light buckwheat flour demonstrated good quality. The colour measurements indicated that buckwheat flour addition decreased L* and a* of pasta which did not affect the panel assessment. Furthermore, sensory analysis showed that dried pasta with added buck-wheat flour demonstrated sensory properties fairly similar to the wholegrain wheat pasta. Buckwheat flour supplementation did not significantly affect all evaluated sensory pro-perties except the elasticity that which was evaluated by the panel with a better score.

ACKNOWLEDGEMENTS

This work was supported by the Serbian Ministry of Education and Science (number of the project TR 31029).

INSTRUMENTAL AND SENSORY PROPERTIES OF BUCKWHEAT FLOUR PASTA

ABSTRACT

ABSTRACT

INTRODUCTION

MATHERIALS AND METHODS

Samples

Pasta cooking quality

Colour determination

Sensory evaluation

RESULTS AND DISCUSSION

Colour determination

Sensory evaluation

CONCLUSION

ACKNOWLEDGEMENTS

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