Tatiana Bojňanská

Changes of the dough rheological properties influenced by addition of potato fibre.

Fibre is an important component of diet and nutrition and is one of the groups of biologically important substances consumed in insufficient quantity. One possibility to increase its intake is to enrich with fibre the food consumed in significant quantities, such as bread and pastries. The aim of this experimental work was to verify the influence of the addition of commercially produced potato fibre Potex to wheat flour and to evaluate the changes in physical properties of subsequently prepared doughs. The addition of 1%, 3%, 5% and 7% of Potex has been chosen and rheological properties were evaluated by the means of E-Farinograph (consistency, water absorption, dough development time, stability and degree of softening), Extensograph-E (resistance to extension, maximal resistance to extension, extensibility, extensibility maximum and energy dough), and Amylograph-E (beginning of gelatinization, viscosity, maximum of gelatinization). The addition of Potex depending on the amount changed the physical dough properties: above 3% of addition significantly increased the beginning of gelatinization and with increasing addition the maximum of gelatinization has increased. Based on the evaluation of farinograph curves it can be concluded that the addition of Potex increased water absorption of composite flours, prolonged dough development time and dough stability. Extensograph measurements showed, with increasing addition of Potex the decrease in dough extension. All doughs were easy to process and with the suitable amount of addition their satisfactory parameters could be maintained. From a technological point of view, the addition of fibre (Potex) up to 3% was fully acceptable and did not significantly alter the rheological properties of processed doughs.

Effect of the addition of hydrocolloids on the rheological and baking properties of the products with added spelt flour (Triticum spelta L.).

The paper presents the results of the evaluation of the effect of additives on the rheological properties of composite flour made of wheat flour in the amount of 70% and spelt flour at 30%. As additives guar gum (0.5% by weight of flour) and xanthan gum (0.16% by weight of flour) were used. Properties of produced control dough and doughs with hydrocolloids were evaluated by means of rheological appliances by Farinograph, Extenzograph, Amylograph and Rheofermentometer. Based on the observed results it can be concluded that the addition of xanthan gum has a positive effect on increasing of farinographic water absorption capacity, extension of dough development time and dough stability and generally positively affected farinographic properties. The addition of guar gum has improved especially extensographic properties as extensographic energy and extensographic resistance. Based on amylographic evaluation of control doughs and doughs with additives it can be stated that in the dough with guar gum the amylographic maximum has slightly increased. Hydrocolloid guar gum contributed to an increased retention capacity of dough observed. Based on our measurements we can indicate that addition of guar and xanthan gum contributed to an increased rheological quality of doughs prepared with addition of flour from spelt wheat. With reference to the baking experiment it was found that the use of hydrocolloids has a positive effect on the improvement of the baking properties, in particular larger volume, specific volume, and the volume yield of the dough with the addition of guar and xanthan gum compared to the control. Our results showed that aditives significantly influenced rheological qualities of dough and a baking quality of products. These findings thus allow optimizing the recipe in order to increase the technological quality of leavened bakery products.

MOLECULAR PROPERTIES OF SELECTED POLYSACCHARIDES DETERMINED BY SEC CHROMATOGRAPHY AND THEIR IMPACT ON WATER ABSORPTION OF WHEAT FLOUR

Chemical composition and solubility in water of selected polysaccharides as β-glucan, arabinoxylan and inulin preparation were determined. All these preparation were of good purity, they consist of at least 71% of polysaccharide of intrest. Solubility in water was the highest in the case of inulin and the lowest in the case of β-glucan. Molecular properties of examined preparations were determined by SEC chromatography. β-glucan and arabinoxylan were of much higher molecular mass than inulin. Molecular mass of examined polysacharides was corelated with increase of water absorption of the flour caused by 2% addition of each polysaccharide. doi:10.5219/173

Process of obtaining of sugar from sugar beet and influence on its quality

Cooking of massecuites has been study in the connection with different particle size distribution of white sugar. During the crystallization is possible to operate with parameters which have influence on particle size of white sugar. Dry matter of juice in crystallizer, volume of the standard syrup in crystallizer and heating curve of crystallization process are constant parameters in this process. Quantity of slurry (seed magma crystallizate) and volume of slurry massecuite are parameters which can be changed for control the particle size distribution of white sugar. Five variants of viable parameters have been trying for obtain ideal particle size distribution of white sugar. As a best has been evaluated variant with 1100 cm 3 of slurry and 20 % of volume of slurry massecuite in crystallizer. This variant has had the crystals proportions captured by the sieves between 1.00 and 0.40 mm with minimal differences in weight. More results have been related to reduction of losses of sugar in molasses with the right setting for the line of cooling crystallization process. The looses of sugar can be reduced by adding two coolers in the end of cooling crystalization process what will decrease a temperature to 40 ° C. This temperature will lead to more efficient crystallization in the cooling crystallization process. doi:10.5219/122

INFLUENCE OF NATURAL ADDITIVES ON PROTEIN COMPLEX OF BREAD

The study focuses on researching the influence of natural additives on certain technological characteristics of mixtures used for bread production, more particularly the influence of N substances in used raw material on selected qualitative parameters of bread. The blends for bread production to be analysed were prepared by mixing wheat flour with an addition of oat, buckwheat, lentil and chickpea wholegrain flour in different portions (10, 20, 30, 40 and 50 %). The experiment showed that the addition of natural additives worsened the protein complex of the blends used in bread production (worsening also qualitative parameters known as product volume). The loaves prepared with an addition of buckwheat, oat, lentil and chickpea were evaluated to be of a lesser quality from a technological viewpoint when compared with pure wheat loaves. The lower content of gluten forming proteins and the generally changed protein composition of blends due to additives caused a lower percentage of wet gluten content, its lower extensibility and swelling capacity. The sedimentation value (Zeleny index) decreased proportionally with the increase of addition until the level was unsatisfactory for raw material intended for bakery purposes. The N content in experimental loaves was higher than in the reference loaves and it increased according to the selected additive and its portion in the blend (more with the addition of lentil and chickpea, less in case of buckwheat and oat) which is considered as positive from a nutritional point of view. But from the technological point of view the additives did not show any positive influence and caused a lower loaf bread volume. The most significant decrease of the loaf bread volume was found with the addition of 50 % of buckwheat (- 45.6 %). Better results were obtained with a lower portion of the additive: loaf with an addition of 30 % of chickpea (volume decreased by 12.8 %) > loaf with an addition of 30 % of lentil (volume decreased by 8.7 %) > loaf with an addition of 10 % of oat (volume decreased by 14.3 %) > loaf with an addition of 10 % of buckwheat (volume decreased by 22.7 %). Such products can be considered as technologically good or at least satisfactory. To increase the volume of bread loaves, 3 % of vital wheat gluten was added to blends mixed with a portion of 30 % and 50 % of additives. The results were not adequate however. The only exception was buckwheat, where the loaf volume was satisfactory despite the addition of 30 %. doi:10.5219/77

Influence of the xanthan gum addition on the technological and sensory quality of baking products during the freezing storage

The influence of the 0.16% xanthan gum addition in the recipe of the bread production and its influence on the baking and sensory quality of products was monitored during the process of our research. Prepared dough was inserted in the freezing box directly (-18°C) and it was stored for one, two, three, four, five and six months. When the baking process was finished, the products with xanthan gum and the products without it were compared and evaluated by both objective and subjective methods. It was found that freezing, cooling and storage of the products without xanthan gum addition influenced the volume, vaulting and general appearance of the products in a negative way and loaves of bread were evaluated as unacceptable after four months of freezing. The quality of experimental loaves of bread with xanthan gum was, even after six months of freezing storage, comparable with freshly baked products. Despite the freezing, the volume of the products had an increased value. After first month of freezing the volume increased by 28.6% and after two months of freezing it increased by 23.8% both compared to the control. The vaulting in products processed by freezing was in the required optimal level during the whole period of freezing. Sensory evaluation results of loaves of bread with xanthan gum were the best after three, four and five months of storage in a freezer, when 98 points were achieved. During the monitored period of freezing, the addition of 0.16% of xanthan gum markedly contributed to the preservation of sensory and baking quality of the frozen wheat dough.

The influence of additional fluors on the retention ability of dough and the technological quality of bakery products

The work monitored rheofermentation properties of dough prepared from composite flours formed by 70% of wheat flour T650 and the addition of 30%. Three kinds of additions were used, namely spelt flour, amaranth flour and buckwheat flour. To determine rheofermentation properties Rheofermentometer Rhea F4 was used, by means of which the dough development, the production of fermentation gases, retention ability of dough and the activity of used baking yeast were analysed. The best ability to retain formed fermentation gas had wheat flour (control) and composite flour with the addition of spelt flour. The composite flour with addition of amaranth flour showed a retention coefficient compared to the control lower by 13%, and the composite flour with addition of buckwheat flour showed a retention coefficient compared to the control reduced by 20%. Control flour and composite flours were then processed in the baking experiment. Based on its results it was possible to evaluate the effect of the addition and retention capacity of dough on the quality of the final products (experimental loaves). The biggest loaf volume (200 cm 3 ) and the optimal vaulting (0.65) were found in the control and a loaf made of composite flour with addition of spelt. Loaf volume, produced from composite flours with the addition of amaranth, and buckwheat was compared to control lower by 18.7%, and 16.3% respectively. The value of vaulting of these products (0.40) can be evaluated as unsatisfactory. Based on the evaluation of results observed by measuring on the rheofermentometer and baking experiment results it can be concluded that a better ability to retain the formed fermentation gas, thus ensuring high volume, had loaves made from wheat flour T650 and composite flour with addition of spelt flour. Based on the findings, it is possible to state that the results of rheofermentometric measurements predict the volume and vaulting of bakery products. By means of Rheofermentometer valuable information has been gained concerning the quality of bakery ingredients, especially flour and yeast.

EFFECT OF MILLING SOFTNESS ON BASIC TECHNOLOGICAL PARAMETERS OF WORT

Crushing the malted grain in the process of milling enables extractive substances of malt to become available for water which accelerates dissolving and other chemical and physical processes during the time of mashing. The aim of this work was at the basis of performed analyses to evaluate to what extent the grist composition with regard to different proportion of meal fraction affects the amount of extract and other technological parameters of malt. Analyzed malt was made from four varieties of malting barley as are Nitran, Ebson, Malz and Xanadu coming from the harvest year 2009. Composition of malt grist in great extent influenced the entire process of mashing, lautering and the amount of extract. The highest values of extract were measured by all varieties at the variant III. with the highest content (50%) of the softest fraction meal + powder meal. The difference between variant I. with 10% content of the softest fraction and variant III. with 50% content, was already 3%. The most significant increase of this parameter was found out by varieties Ebson and Malz. Mashing and lautering parameters have not been significantly influenced by the milling variants. More significant differences were found out with regard to wort turbidity. Only variety Malz showed out the turbidity up to 4 EBC units, measured by turbidity meter under the angle 90°. The highest turbidity was measured by variant I. with the lowest proportion of the fraction meal + powder meal.doi:10.5219/111

INFLUENCE OF ADDITION OF OAT AND LENTIL ON THE CONTENT OF THE DETECTED COMPONENTS IN BREAD

In this paper, the results obtained by bread products analysis made with the addition of oats and lentils, which increased its nutrition value are presented. Breads were prepared with addition of 10 %, 20 %, 30 %, 40 % and 50 % which were analyzed for Fe, Mn, Zn, Cu, Co, Ni, Cr, Pb and Cd content. Prepared products were evaluated also from viewpoint of their technological and nutritional value. Use of oat in bread increased with the addition of a quantity of 50 % content of nutritionally significant elements such as Fe (3.2 times), Mn (3.13 times), Zn (2.23 times), Cu (2.01 times) and Cr (1.2 times). The addition of lentils increased particularly Cu content (3.55 times), Zn (2.96 times) and Mn (1.29 times). None of the samples showed exceeded maximum limit (1.0 mg.kg -1 ) for lead. Based on the analysis results it was confirmed, that the most problematic element in our soils and subsequently in the foodstuffs is cadmium. Exceeded values (< 0.1 mg.kg -1 ) were detected in 8 samples from 11, in finished products the values were within the limits ranging from 0.090 mg.kg -1 Cd to 0.180 mg.kg -1 Cd. doi:10.5219/42