INSTRUMENTAL AND SENSORY PROPERTIES OF BUCKWHEAT FLOUR PASTA
sensory properties, pasta, buckwheat flour, cooking quality, colour determination
ABSTRACT
ABSTRACT
The obtained results suggest that the substitution of wheat with buckwheat flour in the formulation of pasta did not influence tested parameters remarkably.
INTRODUCTION
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
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
Sensory evaluation
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).
Sensory evaluation of dry pasta | ||
Visualy | ||
Shape | Colour | Colour uniformity |
5 – Appropriate with no damage
|
Hue: *indicate a differences |
5 – Uniform
|
Palpatory | ||
Fracturability | ||
5 – Excellent resistance to fracture |
Sensory evaluation of cooked pasta | ||||
Olfactory | ||||
Odour | ||||
5 – Appropriate odour, rounded, aromatic |
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Palpatory | ||||
Firmness | Liveliness | Elasticity | Surface adhesiveness | |
5 – Excellent firmness |
5 – Excellent liveliness |
5 – Excellent elasticity 4 – Very good elasticity |
5 – Not sticky |
|
Gustatory | ||||
Chewiness | Granularity | Taste | ||
5 – Excellent chewiness |
5 – Excellent granularity |
5 – Appropriate taste, rounded, aromatic |
RESULTS AND DISCUSSION
Chemical analysis and cooking properties of pastaThe 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
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).
|
Chemical analysis |
Cooking properties |
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Sam- |
Mois- |
Pro- |
Ash |
Cellu- |
Starch |
OCT |
CL |
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.
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
|
Dry samples |
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|
Shape |
Uniformity of colour |
Colour |
Brittleness |
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A |
4.00±0.67a |
4.40±0.52a |
4.40±0.52a |
3.90±0.88a |
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B |
4.00±0.67a |
4.40±0.70a |
4.70±0.48a |
4.30±0.67a |
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|
Cooked samples |
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|
Odour |
Firmness |
Liveliness |
Elasticity |
Surface stickiness |
Chewiness |
Granularity |
Taste |
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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).
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.