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Food Science
Procedia Food Science 1 (2011) 1628 - 1632
11th International Congress on Engineering and Food (ICEF11)
Possibility of using durum wheat flour as an improvement agent in bread making process
Aleksandra Torbicaa, Miroslav Hadnadeva, Tamara Dapcevic Hadnadeva*
a Institute for Food Technology, University of Novi Sad, Bul. cara Lazara 1, Novi Sad 21000, Serbia
Abstract
Over the past decade due to the changed climate in the Mediterranean region, technological quality of Triticum aestivum wheat has varied extremely. The effect of changed climate conditions was demonstrated in a directly (drought, temperature stress, increased rainfall) and indirectly manner (development of pest-field molds and insects). The wheat bug damaged kernels have become a characteristic phenomenon in recent years. The degree of wheat protein damage is influenced by the intensity of wheat bug attack and plant development stage in which the attack takes place. In certain years, wheat harvested in Serbia had very poor technological quality and used additives have not given the desired results. Therefore, a need to find some other possible solutions arose. Since in Serbia durum flour is readily available in the market, it could be used as improvement agent in bread making. Moreover, its novel use would reduce the price of a durum wheat processing products. Therefore, the chemical composition of soft wheat and durum wheat flour samples was investigated. Rheological properties of all raw materials were determined using Farinograph, Extensograph, Amylograph and Alveograph. The baking tests based on durum and common wheat flours were conducted. Also, the volumes of obtained breads were measured and sensory evaluation was performed. Results of the chemical composition and dough rheological properties of tested flour samples showed that they differ in terms of bread baking properties. Comparison of bread made from wheat flour characterized by damaged protein structure, bread made from wheat flour with damaged protein structure and with 50% of wheat flour having excellent quality and bread made from wheat flour with damaged protein structure with 50% of durum flour, revealed that only the addition of durum flour resulted in the bread of appropriate coherent structure and of adequate sensory quality.
©2011PublishedbyElsevier B.V.Selection and/or peer-review under responsibilityof11th InternationalCongress
onEngineeringand Food(ICEF11)Executive Committee.
Keywords:durum flour; bug infested grains; bread quality
1. Introduction
Durum wheat is known for its good taste, pleasant aroma, and high nutritional value. Moreover, bread made from durum wheat flour can be kept fresh for a longer time than bread made from soft wheat flour.
* Corresponding author. Tel.: +381214853779; fax: +38121450725. E-mail address: aleksandra.torbica@fins.uns.ac.rs
ELSEVIER
2211-601X © 2011 Published by Elsevier B.V. Selection and/or peer-review under responsibility of 11th International Congress on Engineering
and Food (ICEF 11) Executive Committee.
doi:10.1016/j.profoo.2011.09.240
Due to of its high glutenin content, dough from durum flour is coarser and less extensible in comparison to dough of common wheat flour. This may sometimes affect the consumer's acceptance, particularly for people not living in the production's area. It has been reported that durum wheat baking performance improves as gluten becomes stronger, but loaf volumes achieved for the best performing durum wheat cultivars are substantially lower than for bread wheat. Many studies acknowledged the inferior baking potential of durum wheat, and focused on improving baking performance by blending durum wheat with common wheat [1]. There is considerable interest in developing durum wheat suitable for both bread-making and pasta-making [2]. Dual-purpose durum wheat is a desirable goal because such cultivars would have alternative markets in years of high production, and could be used in place of bread wheat either alone or in blends with high quality baking flour [3].
In this paper, the aim was to investigate the use of durum flour as improver for common wheat flour with damaged protein complex, especially gluten protein. It was presumed that a greater amount of protein found in durum wheat than in soft wheat flour in a combination with different rheological and elastic properties of gluten in durum flour dough, would not only increase the total amount of protein, but would also compensate for poor protein quality of wheat flour made from wheat that contains wheat bug damaged grains.
2. Materials & Methods
Two different wheat flours (Tritioum neativum and Tritioum Purum) were used as a bread improver and were tested for moisture, protein and ash content as well as for acidity and pH. Empirical rheological measurements (Babender Farinograph, Extensograph, Amylograph and Chopin Alveograph) were also performed [4, 5]. These flours were used to prepare the following flour mixtures: the first flour mixture contained wheat flour obtained from wheat that had 6% wheat bug damaged kernels and soft wheat flour of excellent quality in the ratio 50:50; and the second flour mixture had 50% of flour obtained from durum wheat instead of soft wheat flour of excellent quality. Properties of flour mixtures were investigated using bread baking test followed by sensory analysis which were performed according to internal methods (Institute of food technology, Novi Sad) [6].
3. Results & Discussion
Over the past decade due to the changed climatic conditions technological quality of soft wheat has varied extremely. Especially common manifestation of altered climatic conditions was in an indirect way i.e. wheat bug attack. Technological quality of wheat depended on bug attack intensity as well as on wheat protein damage. Since there are large quantities of wheat with impaired quality, it is necessary to optimize their processing into the final baked goods of satisfactory quality. Despite the presence of a number of commercial bread improvers, the aim of this paper was to investigate the role of durum flour as a special-purpose flour quality improver. The special advantage of the durum flour is that it is market unused by-product of milling durum semolina and that it contains a large amount of good quality proteins. It is well known that wheat bug attack results in protein damage only, especially the gluten complex. Therefore, flour made from such wheat grains is often damaged and even unusable.
In this paper a flour protein quality which was needed to improve was obtained from wheat containing 6% wheat bug damaged kernels. Due to proteolitic gluten damage, their Extensograph energy parameter was impossible to register (it was 0) and bread obtained from that flour was impossible to process. In order to investigate the benefits of using durum flour as bread improver, flour mixtures in equal ratios of wheat bug damaged wheat flour and wheat flour of excellent quality (Tritioum neativum wheat) and a flour mixture of wheat bug damaged wheat flour and durum flour were prepared. Chemical composition and characteristics of two samples used as a flour improver is shown in Table 1.
Table 1. Chemical composition and characteristics of two samples used as a flour improver
Tciticum oastivum wheat flour improver Tciticum Cucum wheat flour improver
Moisture content, % 12.2 10.1
Protein content, % d.m. 10.4 16.7
Ash content, % d.m. 0.40 1.76
Acidity 1.5 3.2
pH 5.61 5.51
The tested samples showed the greatest difference in protein content. Moreover, their protein structure also differs. Due to the mentioned facts, dough prepared with different flour improvers manifested significantly different rheological behaviour.
Table 2 shows values of standard rheological parameters of Triticum oastivum and Triticum durum wheat flour measured by Farinograph, Extenosograph, Amylograph and Alveograph. Although, according to Farinograph measurements, the overall quality (described using quality class) of both types of flours was in the same quality range (B1 class) [7], significant difference in water absorption values of these two types of flour was observed.
Table 2. Values of the standard rheological tests of two samples used as a flour improver
Tciticum oastivum wheat flour Tciticum Cucum wheat flour
improver improver
Farinograph parameters:
Water absorption, % 59.4 74.2
Dough development time, min 1.5 4.0
Dough stability, min 0.5 2.0
Degree of softening, FU 55 60
Quality number 65.9 68.3
Quality class B1 B1
Extensograph parameters:
Energy, cm2 82 73
Resistance (r) (posle 5 min), EU 345 320
Extensibility (E), mm 139 144
Ratio number (r/E) 2.48 2.22
Amylograph parameters:
Maximum viscosity, AU 750 1440
Alveograph parameters:
Maximum over pressure (P), mm 59 95
Average abscissa at rupture (L), mm 74 55
Index of swelling 19.2 16.6
Deformation energy, 10-4 J 141 167
Ratio P/L 0.79 1.72
This was influenced by higher amount of proteins found in durum wheat flour and their different properties in comparison to the flour from Oaiticum oestivum wheat. Values of Extensograph parameters were excellent for both types of flour, characterized with good energy values, similar uniaxial extensibility, and optimal ratio numbers for bread making process.
Maximum viscosity values measured by Amylograph, although not being the optimal one, indicated the absence of any starch damage in both flour samples. The value of the deformation energy, measured by Alveograph, was greater for durum wheat flour, which means that the durum flour dough had more expressed gas retaining capacity in the fermentation process.
Breads were evaluated sensory 24 h after baking through experienced taste panel (6 panellists). All sensory properties of tested bread samples were expressed as descriptive one instead of using scores. This was done in order to facilitate comparison of bread quality differences which were not very significant (Table 3). Addition of both flour improvers resulted in better dough formation, i.e. better gluten complex proteins bonding, which influenced the appearance of bread sample which breadcrust was coherent with breadcrumb (Fig. 1). According to data presented in Table 3, it can be concluded that durum flour expressed better flour improving properties in comparison to Oaiticum oestivum flour improver. Those improvements were mostly related to crosslinking degree of gluten complex proteins. This was reflected in more regular bread shape, decreased number of cracks, better breadcrumb and breadcrust elasticity. According to sensory analysis, it was proved that bread A had acid and frayed smell and it had grey breadcrumb colour which was crumbly. Bread B was characterized by less crumbly, yellow breadcrumb colour and bread C had light yellow breadcrumb which was not crumbly and moist to the touch. Moreover, its breadcrust was thicker in comparison to bread samples A and B and it had smell that is characteristic for durum.
Table 3. The results of sensory evaluation of the three bread samples produced in bread baking test
Bread produced from low quality flour (Oaiaicum oestivum wheat with 6% wheat bug FomogeF kernels) Bread produced from flour mixtures of low quality flour (Obiaicum oestivum wheat with 6% wheot bug FomogeF kernels) and soft wheat flour improver in 50%:50% ratio Bread produced from flour mixtures of low quality flour (Oaiaicum oestivum wheat with 6% wheot bug FomogeF kernels) and durum wheat flour improver in 50%:50% ratio
Shape slightly irregular, cracks at the top and at the sides slightly irregular, cracks at the sides regular
Specific volume 3.19 3.11 3.03
Ratio h/d 72/150 65/148 61/160
Porosity according to Dallman 8 8 to 7 7
Breadcrumb elasticity satisfactory satisfactory- almost good
Uniformity of breadcrumb uniform uniform fairly uniform
Breadcrumb pores fineness little rough- little rough little rough +
Breadcrust colour gold dark gold dark
Breadcrust shine without gloss without gloss without gloss
Breadcrust thickness medium thick medium thick thick
Breadcrust elasticity elastic, tough elastic, soft elastic, soft+
Fig. 1. Scanned bread structure: (A) Bread produced from low quality flour (Tsisioum atstivum wheat with 6% wheat bug Camagtk ktsetls); (B) Bread produced from flour mixtures of low quality flour (Tsisioum atstivum wheat with 6% wheat bug Camagtk ktsetlss) and soft wheat flour improver in 50%:50% ratio; (C) Bread produced from flour mixtures of low quality flour (Tsisioum atstivum wheat with 6% wheat bug damaged ktsetls) and durum wheat flour improver in 50%:50% ratio
4. Conclusion
The results presented in this paper suggest that implementation of durum flour as bread improver in bread processing based on wheat flour with damaged protein properties can be accomplished resulting in final products with adequate quality. Also, this could have a positive economic effect in terms of using raw materials which do not satisfy the minimum quality demands for wheat bread processing.
5. Acknowledgements
This work was supported by the Project TR 31007, Ministry of Science and Technological Development, Republic of Serbia.
References
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[3] Boggini G. & Pogna, N.E. The breadmaking quality and storage protein composition of durum wheat. J Ctstal doi 1989; 9: 131-138.
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[5] ICC Standard No. 121: Method for Using the Chopin Alveograph
[6] Baking test according to internal procedure of Institute for Food technology in Novi Sad
[7] Pravilnik o kvalitetu zita, mlinskih i pekarskih proizvoda, testenina i brzo smrznutih testa. Regulation on quality of cereals, flour and bakery products, pasta and quick frozen dough. Sl. list SRJ, br. 52/95 i Sl. list SCG, br. 56/2003 - dr. pravilnik i 4/2004 -dr. pravilnik)
[8] Torbica A., Antov M., Mastilovic J., Knezevic D. The influence of changes in gluten complex structure on technological quality of wheat (Tsitioum atstivum L.). PrrC Rts let 2007; 40:1038-1045.
Presented at ICEF11 (May 22-26, 2011 - Athens, Greece) as paper FPE778.
