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Five varieties of vegetable oil underwent oleogelation with two types of wax as follows: beeswax (BW) and rice bran wax (RW). The oleogels were analyzed for their physicochemical, thermal, and textural characteristics. The oleogels were used in the bun dough recipe at a percentage level of 5%, and the textural and rheological properties of the oleogel doughs were analyzed using dynamic and empirical rheology devices such as the Haake rheometer, the Rheofermentometer, and Mixolab. The thermal properties of beeswax oleogels showed a melting peak at a lower temperature for all the oils used compared with that of the oleogels containing rice bran wax. Texturally, for both waxes, as the percentage of wax increased, the firmness of the oleogels increased proportionally, which indicates better technological characteristics for the food industry. The effect of the addition of oleogels on the viscoelastic properties of the dough was measured as a function of temperature. All dough samples showed higher values for G′ (storage modulus) than those of G″ (loss modulus) in the temperature range of 20–90 °C, suggesting a solid, elastic-like behavior of all dough samples with the addition of oleogels. The influence of the beeswax and rice bran oleogels based on different types of vegetable oils on the thermo-mechanical properties of wheat flour dough indicated that the addition of oleogels in dough recipes generally led to higher dough stability and lower values for the dough development time and those related to the dough's starch characteristics. Therefore, the addition of oleogels in dough recipes inhibits the starch gelatinization process and increases the shelf life of bakery products. [ABSTRACT FROM AUTHOR]

Formulating basic food to improve its nutritional profile is one potential method for food innovation. One option in formulating basic food such as bread is to supplement flours with specified amounts of non-bakery raw materials with high nutritional benefits. In the research presented here, we studied the influence of the addition of curcumin and quercetin extracts in amounts of 2.5% and 5% to wheat flour (2.5:97.5; 5:95). The analysis of the rheological properties of dough was carried out using a Mixolab 2. A Rheofermentometer F4 was used to assess the dough's fermentation, and a Volscan was used to evaluate the baking trials. The effect of the extracts on the rheological properties of dough was measured and found to be statistically significant, with curcumin shortening both dough development time and dough stability. Doughs made with greater quantities of extract had a greater tendency to early starch retrogradation, which negatively affects the shelf life of the end products. The addition of extracts did not significantly affect either the ability to form gas during fermentation or its retention, which is important because this gas is prerequisite to forming a final product with the required volume and porosity of crumb. Less favourable results were found on sensory evaluation, wherein the trial bread was significantly worse than the control wheat bread. The panel's decision-making might have been influenced by the atypical colour of the bread made with additives, and in case of a trial bread made with quercetin, by a bitter taste. From the technological point of view, the results confirmed that the composite flours prepared with the addition of extracts of curcumin and quercetin in amounts of 2.5% and 5% can be processed according to standard procedures. The final product will be bread with improved nutritional profile and specific sensory properties, specifically an unconventional and attractive colour. [ABSTRACT FROM AUTHOR]

This study focuses on an applicability of the device designed for monitoring dough fermentation. The device combines a complex system of thermodynamic sensors (TDSs) with an electronic nose (E-nose). The device's behavior was tested in experiments with dough samples. The configuration of the sensors in the thermodynamic system was explored and their response to various positions of the heat source was investigated. When the distance of the heat source and its intensity from two thermodynamic sensors changes, the output signal of the thermodynamic system changes as well. Thus, as the distance of the heat source decreases or the intensity increases, there is a higher change in the output signal of the system. The linear trend of this change reaches an R2 value of 0.936. Characteristics of the doughs prepared from traditional and non-traditional flours were successfully detected using the electronic nose. To validate findings, the results of the measurements were compared with signals from the rheofermentometer Rheo F4, and the correlation between the output signals was closely monitored. The data after statistical evaluation show that the measurements using thermodynamic sensors and electronic nose directly correlate the most with the measured values of the fermenting dough volume. Pearson's correlation coefficient for TDSs and rheofermentometer reaches up to 0.932. The E-nose signals also correlate well with dough volume development, up to 0.973. The data and their analysis provided by this study declare that the used system configuration and methods are fully usable for this type of food analysis and also could be usable in other types of food based on the controlled fermentation. The system configuration, based on the result, will be also used in future studies. [ABSTRACT FROM AUTHOR]

Five varieties of vegetable oil underwent oleogelation with two types of wax as follows: beeswax (BW) and rice bran wax (RW). The oleogels were analyzed for their physicochemical, thermal, and textural characteristics. The oleogels were used in the bun dough recipe at a percentage level of 5%, and the textural and rheological properties of the oleogel doughs were analyzed using dynamic and empirical rheology devices such as the Haake rheometer, the Rheofermentometer, and Mixolab. The thermal properties of beeswax oleogels showed a melting peak at a lower temperature for all the oils used compared with that of the oleogels containing rice bran wax. Texturally, for both waxes, as the percentage of wax increased, the firmness of the oleogels increased proportionally, which indicates better technological characteristics for the food industry. The effect of the addition of oleogels on the viscoelastic properties of the dough was measured as a function of temperature. All dough samples showed higher values for G′ (storage modulus) than those of G″ (loss modulus) in the temperature range of 20–90 °C, suggesting a solid, elastic-like behavior of all dough samples with the addition of oleogels. The influence of the beeswax and rice bran oleogels based on different types of vegetable oils on the thermo-mechanical properties of wheat flour dough indicated that the addition of oleogels in dough recipes generally led to higher dough stability and lower values for the dough development time and those related to the dough’s starch characteristics. Therefore, the addition of oleogels in dough recipes inhibits the starch gelatinization process and increases the shelf life of bakery products.

Formulating basic food to improve its nutritional profile is one potential method for food innovation. One option in formulating basic food such as bread is to supplement flours with specified amounts of non-bakery raw materials with high nutritional benefits. In the research presented here, we studied the influence of the addition of curcumin and quercetin extracts in amounts of 2.5% and 5% to wheat flour (2.5:97.5; 5:95). The analysis of the rheological properties of dough was carried out using a Mixolab 2. A Rheofermentometer F4 was used to assess the dough’s fermentation, and a Volscan was used to evaluate the baking trials. The effect of the extracts on the rheological properties of dough was measured and found to be statistically significant, with curcumin shortening both dough development time and dough stability. Doughs made with greater quantities of extract had a greater tendency to early starch retrogradation, which negatively affects the shelf life of the end products. The addition of extracts did not significantly affect either the ability to form gas during fermentation or its retention, which is important because this gas is prerequisite to forming a final product with the required volume and porosity of crumb. Less favourable results were found on sensory evaluation, wherein the trial bread was significantly worse than the control wheat bread. The panel’s decision-making might have been influenced by the atypical colour of the bread made with additives, and in case of a trial bread made with quercetin, by a bitter taste. From the technological point of view, the results confirmed that the composite flours prepared with the addition of extracts of curcumin and quercetin in amounts of 2.5% and 5% can be processed according to standard procedures. The final product will be bread with improved nutritional profile and specific sensory properties, specifically an unconventional and attractive colour.

Dough fermentation in gluten-free bakery products is problematic due to the absence of gluten, which provides advantageous rheological properties. A thermodynamic sensor (TDS) system combined with an electronic nose was tested as an alternative to conventional methods monitoring dough development based on mechanical properties. In the first part, the configuration of the sensors in the thermodynamic system and their response to different heat-source positions, which significantly affect the output signal from the measurement system, were investigated. The practical contribution lies in the application of the measurements to the example of gluten-free doughs with and without edible insect enrichment. An optimized configuration of the thermodynamic system (one sensor on the inner wall of the container at the bottom and another in the middle of the container closer to the top of the dough) in combination with an experimental electronic nose was used for the aforementioned measurement. In some cases, up to 87% correlation between the signal from the TDS and the signals from a professional rheofermentometer Rheo F-4 (Chopin) was demonstrated. The differences between the results can be explained by the use of different techniques. Using a combination of sensor systems in one place, one time and one sample can lead to more comprehensive and robust results. Furthermore, it was shown that the fermentation activity increased in corn dough with the addition of insects compared to dough without the addition. In rice flour dough with the addition of edible insects, fermentation activity was similar to that of the flour without the addition. [ABSTRACT FROM AUTHOR]

The influence of the addition of partially defatted milk thistle seed flour was studied by analyzing the rheological properties of dough in order to further exploit the functionality of partially defatted milk thistle flour in bakery products. The rheological properties of dough were monitored using Mixolab 2 (Chopin Technologies, France). A rheofermentometer F4 (Chopin Technologies, France) was used to check the dough fermentation, and for the baking trials wheat flour, rye flour, and milk thistle flour were kept in the portion: 50:50:0 (control flour); 50:45:5; 50:40:10 and 50:35:15. The addition of different milk thistle flour in the mixtures resulted in a difference in the viscoelastic properties of the dough. The results showed a weakening of the gluten network in all trial mixtures evaluated. The dough development time values of the control flour were 1.20 min, while an addition of milk thistle flour in portions of 5, 10, and 15% increased these values to 1.30 min, 1.90 min, and 2,80 min, respectively. In addition to higher dough development time values, all trial mixtures exhibited also higher stability (5.07 min; 6.25 min and 8.03 min), when compared to the control flour (4.63 min). The trial mixture with 15% milk thistle flour had different characteristics of gelatinization and retrogradation. The rheofermentometer measured the dough characteristics during proofing, and the trial mixtures with the addition of MTF had a retention volume at approximately the same level as the control flour (WRF). The Volscan profiler was used to determine the bread volume and other parameters. All breads had high volume and specific volume values and can be rated as good, with good porosity and ratio. Mixtures containing 5%, 10% and 15% milk thistle flour added to wheat flour + rye flour maintained rheological parameters within the recommended limits for good technological behavior and, consequently, good quality of bakery products. From all of the above data, it can be stated that, with regard to their baking characteristics, these flour mixtures fall into the category of flours suitable for bakery products.

The influence of the addition of partially defatted milk thistle seed flour was studied by analyzing the rheological properties of dough in order to further exploit the functionality of partially defatted milk thistle flour in bakery products. The rheological properties of dough were monitored using Mixolab 2 (Chopin Technologies, France). A rheofermentometer F4 (Chopin Technologies, France) was used to check the dough fermentation, and for the baking trials wheat flour, rye flour, and milk thistle flour were kept in the portion: 50:50:0 (control flour); 50:45:5; 50:40:10 and 50:35:15. The addition of different milk thistle flour in the mixtures resulted in a difference in the viscoelastic properties of the dough. The results showed a weakening of the gluten network in all trial mixtures evaluated. The dough development time values of the control flour were 1.20 min, while an addition of milk thistle flour in portions of 5, 10, and 15% increased these values to 1.30 min, 1.90 min, and 2,80 min, respectively. In addition to higher dough development time values, all trial mixtures exhibited also higher stability (5.07 min; 6.25 min and 8.03 min), when compared to the control flour (4.63 min). The trial mixture with 15% milk thistle flour had different characteristics of gelatinization and retrogradation. The rheofermentometer measured the dough characteristics during proofing, and the trial mixtures with the addition of MTF had a retention volume at approximately the same level as the control flour (WRF). The Volscan profiler was used to determine the bread volume and other parameters. All breads had high volume and specific volume values and can be rated as good, with good porosity and ratio. Mixtures containing 5%, 10% and 15% milk thistle flour added to wheat flour + rye flour maintained rheological parameters within the recommended limits for good technological behavior and, consequently, good quality of bakery products. From all of the above data, it can be stated that, with regard to their baking characteristics, these flour mixtures fall into the category of flours suitable for bakery products. [ABSTRACT FROM AUTHOR]

Highlights • The effect of salt reduction (from 20 to 5 g kg−1) was studied in durum wheat bread. • 80% of consumers would purchase durum wheat bread prepared with 10 g kg−1 salt. • Reduced-salt bread had a less colored crust, with weaker aroma, than control bread. • Reduced-salt bread showed lower amounts of volatile products of Maillard reaction. • Reducing salt in durum wheat bread allowed obtaining less compact loaves. Abstract In the Mediterranean area, being pedoclimatic conditions more favorable to durum than common wheat cultivation, a bread-making tradition from durum wheat has been established. Durum wheat bread has a compact texture, with lower specific volume than common wheat bread. Due to health implications, several studies were carried out to reduce the content of NaCl in common wheat bread, however without considering durum wheat bread. The aim of this work was to assess the effect of salt reduction on quality and acceptability of durum wheat bread, with regard to specific volume, sensory features and aroma profile. Breads prepared with 5, 10, 15, 20 g/kg NaCl were submitted to consumer test. Control bread (20 g/kg salt) was the most appreciated, followed (greater than80% consumers) by bread with 10 g/kg salt, which showed a significantly (p < 0.05) higher specific volume, but lighter crust and weaker aroma (lower amounts of Maillard reaction products and fusel alcohols). [ABSTRACT FROM AUTHOR]

It is a novel idea to make steamed bread by adding potato flour into wheat flour considering the production and nutritional factors of potato. In this study, the influence of potato flour (0–35%) on dough rheology and quality of steamed bread were investigated. Potato flour addition significantly influenced the dough rheological properties and steamed bread quality, such as increased water absorption, the maximum gaseous release height, total volume of CO2 and hardness, while decreased dough stability and specific volume of steamed bread. Moreover, correlation analysis suggested that dough height at the maximum development time, dough stability, water absorption and the phase tangent can be used for predicting the technological quality of steamed bread. Potato-wheat steamed bread had higher dietary fibre, ash content and antioxidant activity than those of wheat steamed bread. The estimated glycemic index decreased from 73.63 (0%) to 60.01 (35%). Considering the sensory evaluation, the steamed bread with 20% potato flour is acceptable. In conclusion, adding appropriate quantity of potato flour to wheat flour for steamed bread production will not only maintain the technological quality, but also can improve the nutritional value of the steamed bread.

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 cm3) 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.

The in situ study of the linear viscoelastic behaviour of complex biological materials with changing volume, such as fermenting dough, poses great challenges to the rheologist. The aim of this study is to develop a new methodology involving a parallel-plate setup with an adjustable gap, to enable time-tracking of the dynamic moduli and density of fermenting dough. Frequency sweep snapshots at specific points in time were obtained in multiwave mode to reduce measurement times, and overfilling effects were taken into account by establishing a calibration curve with unfermented dough. The new test protocol allowed to distinguish the rheological impact of the CO2 gas from that of the other metabolites produced during fermentation. A further validation of the test protocol was achieved by studying the impact of sugar and salt on the fermentation kinetics, for which the results of the oscillatory tests were combined with gas production data obtained with a rheofermentometer. [ABSTRACT FROM AUTHOR]

The inhibition of the residual fermentation in bread doughs, in order to avoid its evolution, could be crucial to achieve reliable qualitative aroma analyses. Several options have emerged up until now, but they present some drawbacks. In this study, a mixture of methyl octanoate and methyl decanoate (Fames) has been suggested as a non-toxic alternative to the traditional use of mercuric chloride (HgCl2). Rheofermentometric analyses revealed that although HgCl2 is quicker, Fames solution is highly effective in less than 20 min. Moreover, when HgCl2 was added to 90 min fermented dough, it exhibited an unexpected behavior with a high release of CO2 without the generation of ethyl alcohol, which could affect the dough structure. SHS-GC/MS analyses of ethyl alcohol and 2/3-methyl-1-butanol corroborated the rheofermentometer's results, with a visible reduction in the peak areas and significant differences in the One-way Anova between Fames doughs and blank doughs. The application of the Fames solution to SPME-GC/MS-QTof analyses involved a reduction in the areas regarding the blank without interferences, showing a logical progression of the volatile compounds over the fermentation time, increasing their concentration from 0 to 90 min. This progression was normally lost when the inhibitors were not added, since the yeast acted in an uncontrolled manner due to the changes of temperature during freezing, thawing or chromatographic analyses, leading to wrong aroma results. [ABSTRACT FROM AUTHOR]

The swelling properties and thus baking performance of starch strongly depend on mechanical starch modification (MSM), which can be influenced by grinding. To analyze the effect of starch influencing factors on dough fermentation properties and specific bread volume, different MSM levels were obtained using a ball mill. This treatment led to an increase in the water-holding capacity and a decrease in the β-amylase activity of the flour. Baking tests were conducted with varied starch modification levels and water additions to analyze the effect of mechanical flour modification and the resulting changes in hydration and gas formation properties of the dough on bread quality. The specific bread volume was lower with high-MSM flour than with low-MSM flour, regardless of the adapted water addition. Therefore, the effect of MSM on dough fermentation properties was examined with respect to different water additions. Despite increasing the water addition, the time of porosity (Tx) of high-MSM dough was significantly lower than that of low-MSM dough. However, the amount of gas leakage after 60 min was quite low for high-MSM dough (gas retention coefficient ~99.5 %) and thus not considered significant. By adding 58 and 83 g water 100 g flour, the gas retention coefficient after 60 min was 100 %. The results also show that lower enzymatic activity with high MSM has no significant effect on the produced gas volume during fermentation. However, increasing MSM leads to a reduced dough height (Hm). [ABSTRACT FROM AUTHOR]

A Principal Component Analysis method based on multivariate analysis was used to evaluate the correlation between the fermentable sugar content of dough and its behaviour during fermentation at different fermentation times of 60, 120, and 180 minutes. The concentration of fermentable sugars during dough fermentation (sucrose, glucose, maltose, and fructose) was determined using a High Performance Liquid Chromatography device. Also, the Chopin Rheofermentometer device was used for the analysis of gas production and dough development at the fermentation times mentioned above. From the aspect of the correlations established between the parameters obtained by the two devices, very good correlations were obtained. For example, the gas production showed a positive correlation with glucose content after 60 min of fermentation (r = 0.846) and a negative correlation with fructose content after 120 min of fermentation time (r = -0.993).

The milling by-products have high nutritional value and can be incorporated into white flour. This study was aimed at comparatively examining the rheological behaviour of the doughs made from wheat white flour with different levels (3-30%) of bran streams incorporated and from wholewheat. The results indicated significant correlations between the ash content of the wheat bran streams incorporated into flour and Alveograph, Rheofermentograph and Mixolab parameters. The white flour sample with 25% wheat bran streams had the ash content similar to wholewheat, but the dough rheology was improved. The quality of the white flour bread with 25% wheat bran streams was improved compared to the wholemeal bread.

One characteristic of the Romanian wheat flour in the recent years consists of high values of the falling number. The aim of the present study was to explore the Mixolab device to characterize the thermo-mechanical behaviour of flour supplemented with different additives that contain α-amylase. Mixolab parameters C4 and C5 were found to be lower in samples with high doses of additives containing α-amylases. The increase of the α-amylase dose reduces the dough stability. The samples that contain higher doses of additives presented low values of the β slope, which gives indications about starch gelatinization. The samples with reduced α-amylases activity showed high values of the γ slope.

The Mixolab device in view of the characterisation of the thermo-mechanical behaviour of ten different flours, and establishing the correlations between the rheological parameters of wheat flour supplemented with different additives such as fungal α-amylase, fungal hemicellulase, and fungal xylanase weres exploted. The rheological measurements were performed using the Mixolab, Alveograph, and Rheofermentometer. Our results indicated significant positive and negative correlations between the parameters investigated. The changes of the Mixolab curve trend depended on the amylase doses. Significant correlations were established also between the Mixolab parameters and the results of the baking tests; the β slope, C2, C3, and C4 were positively correlated with the specific volume of the bread. Taking into account the results obtained, we may conclude that Mixolab is a complex device that renders the evolution of the bread during the entire technological process, from the dough making to the starch retrogradation.

Investigations include the analysis of the impact of commercial products: complex additive (0.1, 0.3, and 0.5%), L-ascorbic acid (0.002, 0.004 and 0.012%), diacetyl ester of tartaric acid with monoglycerides (DATEM E472e, 0.1, 0.3, and 0.5%), α-amylase (0.002, 0.006 and 0.012%), xylanase (0.004, 0.012 and 0.024%), alcohol extract of rosemary, thyme or sage (0.5, 1.0 and 2.0%), as well as the combination of complex additive and rosemary, thyme and sage extract on rheological characteristics of dough. The study includes amylograph, farinograph and extensograph analysis of dough with and without additives (control sample). The volume of lost CO2 gas (mL) is the lowest in dough samples with an added combination of complex additive and thyme extract (0.05 and 0.5%) and rosemary extract (2.0%). In the samples with thyme extract (1.0%) added, the volume of lost gas is at a level of samples with added complex additive, DATEM, and L-ascorbic acid.

Minor variations in the metabolic profile of yeast strongly affect wheat dough structure, the resulting bread volume and its crumb texture. However, it is complex to analyze the impact of single yeast metabolites on the development of dough during processing. In this study, a chemical-leavening system based on glucono-delta-lactone and NaHCO 3 was applied to analyze aeration and gas retention in presence of glutathione independent from the yeast metabolism. The addition of glutathione-amplified gas release during kneading and reduced the time to reach the maximum gas formation rate. The results indicated that the inflation of dough is not limited by the amount of CO 2 nor its release kinetics; however, during baking further aeration is restricted. The oven rise was impaired by high initial CO 2 volumes, which is enhanced by the presence of glutathione. Industrial relevance This investigation addressed the effect of yeast equivalent glutathione on the properties of aerated dough and the resulting bread properties. Through the application of a chemical-leavening system the yeast metabolism can be avoided. GSH from lysed yeast cells had a weakening effect, which confirms observations of structure-loss after freeze–thaw processes of dough. Moreover, the use of chemical-leavening agents reduces bread production costs, since the fermentation process can be neglected. [ABSTRACT FROM AUTHOR]

Distiller's grains, by-product from ethanol production, can be a new source for nutritionally enriched bakery products, particularly because of its high amount of dietary fibre and protein. Ingredients rich in fibre provoke challenges to the dough and bread system; therefore, mechanisms behind dried distiller's grains (DDGs) impact on wheat bread must be evaluated. So, dough and bread characteristics were analysed in bread containing 0-20 % DDG, and effects of pH, particle size and furfural as DDG metabolite were studied. As a result, wheat bread incorporating DDG provides smaller volume from 20 to 45 %, firmer crumb up to a factor of 6 and reduced springiness up to 10 %. However, pH adjustment balanced the negative influence, and the low pH of DDG was revealed as the most influential parameter. The variation of particle sizes could not influence dough or bread characteristics significantly. While the low pH of DDG and the high amount of dietary fibre do not completely explain the negative impacts, inhibiting effects on the activity of Saccharomyces cerevisiae were evaluated. DDGs contain 2.7 ppm furfural as a consequence of the drying process, so its role as inhibiting compound was investigated in a model suspension and dough. It was confirmed that furfural is contributing to structure weakening effects in dough. [ABSTRACT FROM AUTHOR]

The baking performance and gas retention capacity of wheat dough depends on production rate and total volume of CO 2 during fermentation. This study aims to examine the effect of the CO 2 formation kinetics and the gas volume fraction on the structural integrity of wheat dough and the resulting bread quality. The gas release characteristics were evaluated using a rheofermentometer with varied concentrations of compressed yeast and instant dry yeast (CY and IDY respectively). For this purpose, the maximum CO 2 formation rate was calculated through the derivation of hydrostatic pressure curves measured in the rheofermentometer. For CY, the time when gas escapes the dough matrix (Tx, time of porosity) as well as the corresponding gas volume depended on the gas formation rate, whereas the gas retention capacity of wheat dough leavened with IDY was not affected by the CO 2 formation rate. Although the dough leavened with IDY showed improved extensibility during fermentation, the specific bread volume was 21% below that of the samples leavened with CY. These results indicate that an increase in the maximum gas formation rate considerably affects the structural integrity of the dough matrix. Because of the reduction of the loaf volume, the effect is reinforced by the application of IDY. [ABSTRACT FROM AUTHOR]

Gluten-free ( GF) sourdough was prepared from wheat sourdough and analysed both in fresh ( GFS) and dried forms ( DGFS). The gluten content in each GF sourdough sample was <20 mg kg−1. The dough leavening capacity and the properties of the bread samples were investigated and compared to those of bread prepared using bakery yeast ( Saccharomyces cerevisiae). Two commercial rice-based mixtures (different for the presence/absence of buckwheat flour) were used to prepare bread samples. In GFS, lactic acid bacteria ( LAB) and yeasts were found in amounts corresponding to 108 and 107 CFU g−1, respectively, whereas both LAB and yeasts were detected in lower amounts (about 106 CFU g−1) in DGFS. When used in bread-making, both GFS types produced significant dough acidification and exhibited good dough development during proofing, resulting in loaves with specific volume values between 3.00 and 4.12 mL g−1, values similar to those obtained for reference bread (3.05÷4.15 mL g−1). The use of GFS was effective in lowering the bread staling rate during storage for up to 7 days. [ABSTRACT FROM AUTHOR]

Any factor which impairs the development of the gluten network affects the gas retention capacity and the overall baking performance. This study aimed to examine why rising yeast concentrations ( Saccharomyces cerevisiae ) decrease the dough elasticity in an asymptotic manner. Since in 27 commercial fresh and dry yeasts up to 81 mg glutathione (GSH) per 1 g dry sample were found. Through the addition of reduced GSH in dough without yeast, the extent of dough weakening was analysed. Indeed rheological measurements confirmed that yeast-equivalent levels of GSH had a softening effect and during 3 h fermentation the weakening coefficient increased from 0.3% to 20.4% in a Rheofermentometer. The present results indicate that free –SH compounds, as represented by GSH, considerably contribute to the softening of dough through dead yeast cells. [ABSTRACT FROM AUTHOR]

Genetic gains in quality traits were assessed in grain samples from 4 field experiments involving 16 bread wheat varieties representative of those most widely cultivated in Spain during the 20th century. The allelic composition at three glutenin loci ( Glu-A1 , Glu-B1 , and Glu-D1 ) was obtained by PCR-based DNA markers and published references. From 1930 to 2000 grain protein content decreased by −0.030% y −1 , or in relative terms by −0.21% y −1 , but the protein produced per hectare increased by 0.39% y −1 . Alveographic tests revealed significant changes in dough rheological properties. Dough strength ( W ) and tenacity ( P ) increased at relative rates of 1.38% y −1 and 0.99% y −1 , respectively, while dough extensibility ( L ) decreased by −0.46% y −1 , resulting in an increase of 1.45% y −1 in dough equilibrium ( P / L ). The rise in protein quality could be related to the replacement of the null allele by subunits 1 or 2* at Glu-A1 and the prevalence of subunits 7 + 8 and 5 + 10 at Glu-B1 and Glu-D1 loci, respectively, in the most recent varieties. Dough extensibility was affected by water input during the crop cycle, this relationship being partially explained by the presence of the 5 + 10 HMW glutenin subunit. Fermentation tolerance was improved in the most modern varieties. Collapse during fermentation was avoided only in doughs with a W ≥ 159 J × 10 −4 and a P / L ≥ 0.56 mm H 2 O mm −1 , levels achieved by most of the modern varieties. The over-strong and unbalanced rheological properties of some modern varieties resulted in highly porous doughs, and no clear advances in dough maximum height during fermentation were attained. [ABSTRACT FROM AUTHOR]

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 cm3 ) 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. [ABSTRACT FROM AUTHOR]

Abstract: As shown in previous studies the application of yeast presents a challenge for rheological measurements. The continuously produced metabolites of this living organism strongly influence the resulting data. In the study on hand, the method for fundamental oscillatory tests was modified to fit the needs of the flow behavior of yeasted dough. The analysis of the pH-value offered a method to indirectly determine the carbon dioxide production, as was proven by a linear correlation with the density (R 2 = 0.88, p < 0.001). As evidenced by Rheofermentometer measurements, the gas holding capacity of wheat dough was not affected by the kinetics of CO2-production, whereas the total amount of gas was decisive. Moreover, the method associated density correlated significantly (p < 0.001) with the resistance to extension, the extensibility and the complex shear modulus. Finally, different yeast concentrations provoked up to 57% higher loss factors immediately after kneading. In summary, it was proven that yeasted wheat dough was significantly more plastic and susceptible to pressure than the non-leavened models. In turn, this provides a practical and realistic insight into the structural changes of wheat dough as affected by the metabolism of Saccharomyces cerevisiae. [Copyright &y& Elsevier]

Highlights: [•] Merge and adjustments to the one component diffusion model of previous publications. [•] Mathematical modeling of relative dough volume measurements at different conditions [•] Proposal of a monitoring system for computer assisted leavening supervision. [Copyright &y& Elsevier]

Abstract: Fermentation of sugars into CO2, ethanol and secondary metabolites by baker's yeast (Saccharomyces cerevisiae) during bread making leads to leavening of dough and changes in dough rheology. The aim of this study was to increase our understanding of the impact of yeast on dough related aspects by investigating the effect of harvesting yeast at seven different points of the growth profile on its fermentation performance, metabolite production, and the effect on critical dough fermentation parameters, such as gas retention potential. The yeast cells harvested during the diauxic shift and post-diauxic growth phase showed a higher fermentation rate and, consequently, higher maximum dough height than yeast cells harvested in the exponential or stationary growth phase. The results further demonstrate that the onset of CO2 loss from fermenting dough is correlated with the fermentation rate of yeast, but not with the amount of CO2 that accumulated up to the onset point. Analysis of the yeast metabolites produced in dough yielded a possible explanation for this observation, as they are produced in different levels depending on physiological phase and in concentrations that can influence dough matrix properties. Together, our results demonstrate a strong effect of yeast physiology at the time of harvest on subsequent dough fermentation performance, and hint at an important role of yeast metabolites on the subsequent gas holding capacity. [Copyright &y& Elsevier]

Maize gluten feed (MGF) is a secondary product of maize processing with rich dietary fiber content, which remains underexploited as an ingredient by the food industry. In this study, the impact of MGF and fermented MGF (FMGF) incorporation on dough properties and bread quality was investigated. The results indicated that both MGF and FMGF demonstrated beneficial effects on the water absorption, dough development time, setback value while exerting a negative impact on the dough stability time. A significant decrease in L value (extensibility) and W value (deformation energy), and a significant increase in P value (elasticity) were observed with MGF or FMGF incorporation in the dough. For fermentation properties, the maximum height of dough and the volume of the gas retained in dough during fermentation decreased with the substitution level increased. The bread incorporated MGF or FMGF decreased the specific volume, deepened the color, led to lower porosity, increased the crumb hardness and chewiness. MGF and FMGF bread showed a slight depreciation in quality with the substitution level below 10 g/100 g. Compared with MGF, FMGF displayed advantages in bread properties at below 10 g/100 g substitution level, indicating that fermentation is a promising technology for improving the processing properties of MGF. • Raw or fermented maize gluten feed affect dough properties and bread quality. • Raw and fermented maize gluten feed have beneficial on water absorption of dough. • Raw and fermented maize gluten feed are material for fiber-rich bread. • Fermentation display advantages in bread quality at 10 g/100 g substitution level. [ABSTRACT FROM AUTHOR]

Green tea extract (GTE) was fortified into steamed bread as a functional ingredient to enhance its nutritional values. However, GTE might inhibit α-amylase activity and interact with gluten proteins, causing adverse effects on dough development and final loaf volume. This research investigated the effects of GTE and fungal alpha-amylase (FAA) on rheofermentometer characteristics, dough inflation parameters, and the specific volume of both dough and steamed bread. Rheofermentograph showed that the fortification of GTE did not affect the gassing power of yeast while it slightly inhibited the activity of FAA. Fortification of GTE at the level of 1.0 % decreased the dough inflation parameters and the specific volume of steamed bread. On the other hand, fortification of 60 ppm FAA enhanced the dough inflation parameters and increased the specific volume of steamed bread. Addition of 60 ppm FAA was able to fully compensate for the reduction of specific volume caused by the addition of 1.0 % GTE. Fortification of 0.50 % GTE produced steamed bread whose specific volume was not significantly different from that without GTE. [ABSTRACT FROM AUTHOR]

This study assessed the levels of microbial contaminants in liquid, compressed and dry commercial baker's yeasts used as starters in breadmaking. Eumycetes, Enterobacteriaceae, total and fecal coliforms, Bacillus spp., and lactic acid bacteria (LAB), in particular enterococci, were quantified. Results obtained in this study highlighted that baker's yeast could represent a potential vehicle of spoilage and undesirable microorganisms into the baking environment, even if these do not influence the leavening activity in the dough, as ascertained by rheofermentometer analysis. Different microbial groups, such as spore-forming bacteria and moulds, were found in baker's yeast starters. Moreover, different species of LAB, which are considered the main contaminants in large-scale yeast fermentations, were isolated and identified by Denaturing Gradient Gel Electrophoresis (DGGE) and 16S rDNA sequencing. The most recurrent species were Lactobacillus plantarum, Enterococcus faecalis, and Enterococcus durans, isolated from both compressed and dry starters, whereas strains belonging to Leuconostoc and Pediococcus genera were found only in dry ones. Nested-Polymerase Chain Reaction (Nested-PCR) and Randomly Amplified Polymorphic DNA-PCR (RAPD-PCR) were also used to highlight the biodiversity of the different commercial yeast strains, and to ascertain the culture purity. [ABSTRACT FROM AUTHOR]

A Principal Component Analysis method based on multivariate analysis was used to evaluate the correlation between the fermentable sugar content of dough and its behaviour during fermentation at different fermentation times of 60, 120, and 180 minutes. The concentration of fermentable sugars during dough fermentation (sucrose, glucose, maltose, and fructose) was determined using a High Performance Liquid Chromatography device. Also, the Chopin Rheofermentometer device was used for the analysis of gas production and dough development at the fermentation times mentioned above. From the aspect of the correlations established between the parameters obtained by the two devices, very good correlations were obtained. For example, the gas production showed a positive correlation with glucose content after 60 min of fermentation (r = 0.846) and a negative correlation with fructose content after 120 min of fermentation time (r = -0.993). [ABSTRACT FROM AUTHOR]

BACKGROUND: Maize, one of the suitable grains for coeliac consumption, is, together with rice, the most cultivated cereal in the world. However, the inclusion of maize flour in gluten-free bread is a minority and studies are scarce. This paper analyses the influence of different maize flour types and their particle sizes on the quality of two types of bread without gluten (80% and 110% water in the formulation) obtained from them. We also analysed the microstructure of the dough and its behaviour during the fermentation. RESULTS: Finer flours had a lower dough development during fermentation in all cases. Among the different types of flour, those whose microstructure revealed compact particles were those which had higher specific bread volume, especially when the particle size was greater. Among the formulations, the dough with more water gave breads with higher specific volume, an effect that was more important in more compact flours. The higher volume breads had lower values of hardness and resilience. CONCLUSION: The type of corn flour and mainly its particle size influence significantly the dough development of gluten-free bread during fermentation and therefore the final volume and texture of the breads obtained. The flours having coarser particle size are the most suitable for making gluten-free maize bread. © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: Fermenting yeast does not merely cause dough leavening, but also contributes to the bread aroma and might alter dough rheology. Here, the yeast carbon metabolism was mapped during bread straight-dough fermentation. The concentration of most metabolites changed quasi linearly as a function of fermentation time. Ethanol and carbon dioxide concentrations reached up to 60mmol/100g flour. Interestingly, high levels of glycerol (up to 10mmol/100g flour) and succinic acid (up to 1.6mmol/100g flour) were produced during dough fermentation. Further tests showed that, contrary to current belief, the pH decrease in fermenting dough is primarily caused by the production of succinic acid by the yeast instead of carbon dioxide dissolution or bacterial organic acids. Together, our results provide a comprehensive overview of metabolite production during dough fermentation and yield insight into the importance of some of these metabolites for dough properties. [Copyright &y& Elsevier]

One characteristic of the Romanian wheat flour in the recent years consists of high values of the falling number. The aim of the present study was to explore the Mixolab device to characterize the thermo-mechanical behaviour of flour supplemented with different additives that contain α-amylase. Mixolab parameters C4 and C5 were found to be lower in samples with high doses of additives containing α-amylases. The increase of the α-amylase dose reduces the dough stability. The samples that contain higher doses of additives presented low values of the β slope, which gives indications about starch gelatinization. The samples with reduced a-amylases activity showed high values of the γ slope. [ABSTRACT FROM AUTHOR]

Rheofermentometer assays were used to characterize the leavening of sour-doughs produced using species of lactic acid bacteria (LAB) and yeasts, alone or in combination. Saccharomyces cerevisiae 141 produced the most CO and ethanol whereas S. exiguus M14 and Lactobacillus brevis subsp. lindneri CB1 contributed poorly to leavening and gave sour-doughs without porosity. In comparison with that seen in sour-dough produced with yeast alone, yeast fermentation with heterofermentative LAB present was faster whereas that with homofermentative LAB ( L. plantarum DC400, L. farciminis CF3) present was slower and produced more CO. Combining L. brevis subsp. lindneri CB1 with S. cerevisiae 141 decreased bacterial cell numbers and souring activity. However, addition of fructose to the sour-dough overcame these problems as well as activating S. cerevisiae 141. [ABSTRACT FROM AUTHOR]

The influence of the addition of four legume flours, chickpea, broad bean, common bean and red lentil (in amounts of 5%, 10% and 15% to a wheat-rye composite flour (50:50:0-control flour), in ratios of 50:45:5; 50:40:10; 50:35:15) was studied by analyzing the rheological properties of dough in order to further exploit the functionality of legume flours in bakery products. The rheological properties of dough were monitored using a Mixolab 2. A Rheofermentometer F4 was used to check the dough fermentation, and a Volscan was used for evaluating the baking trials. The addition of different legume flours in the mixtures resulted in different viscoelastic properties of the dough. The results showed a weakening of the protein network depending on the amount of legume flour added and on the specific legume flour. On the contrary, all samples with a higher proportion of legume flour showed an increased resistance to starch retrogradation. All flours had the ability to produce a sufficient volume of fermenting gases, with the exception of flours with a higher addition of broad bean flour, and the baking test confirmed a lower bread volume for bread with this addition. The results of the sensory evaluation indicated that legume flour additions resulted in breads with an acceptable sensory quality, in the case of additions of 5% at the same level as the bread controls, or even better. The aromas and flavors of the added non-cereal ingredients improved the sensory profile of wheat-rye bread. Breads with additions of chickpea, common bean and broad bean had a considerable proportion of darker colors in comparison to the control bread and bread with red lentil. [ABSTRACT FROM AUTHOR]

This study aimed at understanding how the presence or absence of NaCl influences dough rheological performance of soft wheat cvs. currently used in the Italian bread manufacturing industry as a scientific support to national health strategies to reduce the use of NaCl in bread. For this reason 176 flour samples belonging to 41 soft wheat cvs. currently cultivated in Italy, were analyzed for their protein content, Zeleny sedimentation value, and by means of the Chopin Alveograph and Brabender Farinograph, with no salt and with 1.5% salt addition (average salt content in Italian bread). Three selected cvs. (Aubusson, Bolero, and Blasco) were additionally studied by means of the Rapid Visco Analyzer (RVA) at three levels of salt addition (0%, 1.5% and 3.0%). The fermentation behaviour of the cvs. Aubusson and Blasco was also studied by means of a Rheofermentometer under the same conditions. The results of our study confirmed the role of salt in strengthening the wheat gluten network (up to 86%), and thus the gas retention of dough and in affecting yeast activity. However, it also definitely proved that careful cultivar selection can help in overcoming technical challenges in reduced-salt bread manufacturing and eventually, it opens the path to wheat breeding for reduced-salt bread baking. [ABSTRACT FROM AUTHOR]