Dough Mixing Research Articles

Comprehensive Analyses of Carbohydrates, 1,2-Dicarbonyl Compounds, and Advanced Glycation End Products in Industrial Bread Making.

The technology of bread making is characterized by three major steps: dough mixing, proofing, and baking. To follow the course of Maillard processes in an authentic food matrix, the complete manufacturing process of wheat bread rolls was assessed along all production steps with the quantitation of sugars, furfurals, 1,2-dicarbonyl compounds, and advanced glycation end products (AGEs). As a result, the AGE profile was significantly enlarged to more than 12 structures, and comprehensive mechanistic insights were provided. The analyses of five major German bread types including wheat, brown, rye bread, pumpernickel, and crispbreads led to AGE contents of 69-149 mg/kg bread or 984-1857 mg/kg protein. Major lysine protein modifications were carboxymethyl, carboxyethyl, and formyl lysine and pyrraline. Arginine was mainly modified by methylglyoxal (MGO) to give imidazolinones. A major part of MGO was confirmed to stem from microbial metabolism.

Molecular interactions between gluten network and phenolic acids studied during overmixing process with application of FT-IR spectroscopy

FT-IR spectroscopy was used to study structural changes in the gluten network caused by supplementation of the model dough with selected phenolic acids. Additionally, effect of the overmixing (extension of the mixing time to 60 and 75 min) on the gluten structure was determined. Eight phenolic acids (cinnamic and gallic acid derivatives) differing in functional groups present at aromatic ring and molecular size were added to model dough in the amount of 0.05%, 0.1%, and 0.2%. Structural changes as a result of the supplementation were studied in the samples collected before dough breakdown and at the end of dough mixing. Analysis of changes in the secondary structure and water populations showed that overmixing process combined with supplementation led to a gradual mechanical destruction that concerns mainly glutenins. It was observed as aggregates formation, breakage of intramolecular hydrogen bonds within gluten network and breakage of strong H bonds between gluten proteins and water molecules. Additionally, the results of ‘before dough breakdown’ samples indicated that cinnamic acid derivatives can incorporate into gluten network, whereas gallic acid derivatives can be enclosed in the hydrophobic pockets and compete for water with gluten proteins.

Processing a 100% legume pasta in a classical extruder without agglomeration during mixing.

Pasta made exclusively from legume has high nutritional potential (rich in protein and gluten free). However, it is difficult to produce 100% legume dough suitable for the extrusion step in pasta production that comprises hydration, mixing, and extrusion. This paper addresses the biochemical phenomena at the origin of the agglomeration of dough particles frequently reported in the literature, which results in very sticky dough that cannot be extruded. We tested changes in mixing conditions including mixing temperature, addition of antioxidants, and flour pretreatment. Our results suggest that enzymatic reactions, notably lipoxygenase related redox activity, are responsible for this impairment of dough mixing and extrusion. Some of the process conditions studied can be applied at industrial scale and will help produce a legume food with nutritional and culinary qualities, beneficial for people with celiac disease, or gluten intolerance, as well as the general population.Practical ApplicationIn the context of a sustainable and healthy food transition, the food industry is developing legume‐based food of high nutritional quality that is widely consumed, like pasta. However, using legumes often leads to technological problems during the mixing and extrusion of pasta. This article demonstrates they are linked to enzymatic oxidative phenomena and provides an easy solution to reduce the problems without drastically changing pasta processing. Applied at industrial scale, it will allow the production of naturally gluten‐free pasta rich in protein (two to three times the protein content of wheat pasta), of good nutritional quality.

The bean flour effect on the rheological properties of the dough from a wheat flour based composite mixture

Department of Food Technology, at Saratov State Vavilov Agrarian University, studied and compared the main parameters of the rheological state of the dough from whole grain wheat flour and straight white wheat flour, dough from white beans and red beans. Dough parameters from flour composite mixtures based on beans were also studied and compared with each other. It was found that the water absorption ability of flour highly correlates with dough stability time, with a force moment characterizing the minimum consistency of the dough during the starch retrograde phase and with a force moment characterizing the maximum consistency of the dough during the end of the starch retrograde phase, as well as with the total energy consumed during dough mixing. To a lesser extent, the water absorption ability of flour correlates with the time of dough development, the force moment during the liquefaction phase, and the force moment characterizing the stability of the dough during the gelatinization phase. When comparing the main rheological parameters of the dough from the studied types of flour, it was found that both the degree of grinding and the morphological characteristics of the beans used as a donor or basis for composite mixtures influence the correlation between rheological parameters. The water absorption ability correlates to a greater extent with the main rheological indices of the dough of composite mixtures based on straight white wheat flour rather than composite mixtures based on whole grain flour.

Rheological and microstructural characterization of wheat dough formulated with konjac glucomannan.

This work aimed to investigate the effects of different levels of konjac glucomannan (KGM) on the thermomechanical and pasting properties, water distribution, gelatinization, texture, and microstructural characteristics of wheat flour and dough. The thermomechanical properties assessed with a Mixolab showed that KGM could increase the water absorption and degree of softening and decrease the stability time of wheat dough. In addition, wheat flour starch with KGM underwent significant (P < 0.05) gelatinization changes according to the rapid viscosity analyzer and differential scanning calorimetry results. These results demonstrated that KGM enhanced the thermal stability and anti-aging capacity of wheat flour. All doughs with KGM exhibited viscoelastic behavior but lower hardness and gumminess. Low-field nuclear magnetic resonance showed that water, with a tight binding force, migrated to the weaker binding forces in the dough. A noticeable disruption of the gluten network was observed at the highest level of KGM. However, an intermediate level of KGM addition (10 or 15 g kg-1 flour) still rendered dough with satisfactory properties. A certain amount of KGM could enhance the thermal stability and anti-aging ability of wheat flour, improve the viscoelastic behavior, and decrease the hardness and gumminess of dough. In general, the mixing of flour and dough with KGM addition of 10 or 15 g kg-1 flour was of good quality. © 2021 Society of Chemical Industry.

Dynamic Changes in Glutenin Macropolymer during Different Dough Mixing and Resting Processes.

The glutenin macropolymer (GMP), which is an important component of the glutenin protein in wheat flour, plays a prominent role in governing dough properties and breadmaking quality. This study investigated the changes in GMP properties during the mixing and resting stages of dough processing. The results show that the GMP content decreases by about 20.20% when the mixing time increases from 3 to 5 min, while increasing the resting time can lead to restoration of some GMP contents. Resting promotes greater formation of large-sized GMP particles, which is likely related to the increased disulfide bond content in the GMP during this process. In contrast, the mechanical force of mixing causes GMP depolymerization and formation of smaller particles. Furthermore, after mixing, the protein secondary structure tends to be disordered, the protein morphology becomes irregular, and the protein subunit ratio changes. Thus, mixing has many of the opposite effects to resting, although resting can (to some extent) restore the properties of the GMP after mixing. However, excessive resting time can lead to negative results, reflected in lower disulfide bond (SS) and GMP contents, and more irregular particle sizes. The presented results suggest that dough mixing induces rearrangement of the dough’s protein structure, and resting somewhat restores the chemical bonds and internal protein structure.

Characterisation and improvement of the quality of mixing of recycled thermoplastic composites

A low-shear mixer was used to blend thermoplastic composite scrap material into a molten mixed dough, which was then compression moulded. This process is a key step in a novel recycling solution for thermoplastic composites. A study was carried out to characterise the quality of mixing (QoM) of the blended doughs to understand how to improve the QoM of mixed doughs towards further improvement and implementation of the recycling solution. In order to achieve this, the effect of mixing parameters and fibre length on the QoM were studied. This study used shredded C/PPS flakes, originating from consolidated laminate scrap. These flakes are about 20 mm in size, and contain woven fabric reinforcement, making them far different from regular pellets, and therefore more difficult to mix. The QoM was characterised by means of image analysis of a large set of cross-sectional microscopy images, based on which the scale and intensity of segregation of the fibre clusters were evaluated. Bundle size distribution was determined by applying Delaunay triangulations to cluster the fibre centres. These methods were found to be suitable for characterising the QoM of such doughs. Increasing the mixing time and mixing speed were identified as key ways to improve the mixing process. With the current mixing machine, it is also suggested not to use fibres longer than 15 mm on average in order to limit intra-dough variability. For doughs made of fibres longer than 15 mm, improvements on the mixing device could sufficiently increase the QoM.

Effects of Physical and Chemical Factors on the Structure of Gluten, Gliadins and Glutenins as Studied with Spectroscopic Methods.

This review presents applications of spectroscopic methods, infrared and Raman spectroscopies in the studies of the structure of gluten network and gluten proteins (gliadins and glutenins). Both methods provide complimentary information on the secondary and tertiary structure of the proteins including analysis of amide I and III bands, conformation of disulphide bridges, behaviour of tyrosine and tryptophan residues, and water populations. Changes in the gluten structure can be studied as an effect of dough mixing in different conditions (e.g., hydration level, temperature), dough freezing and frozen storage as well as addition of different compounds to the dough (e.g., dough improvers, dietary fibre preparations, polysaccharides and polyphenols). Additionally, effect of above mentioned factors can be determined in a common wheat dough, model dough (prepared from reconstituted flour containing only wheat starch and wheat gluten), gluten dough (lack of starch), and in gliadins and glutenins. The samples were studied in the hydrated state, in the form of powder, film or in solution. Analysis of the studies presented in this review indicates that an adequate amount of water is a critical factor affecting gluten structure.

Process- and material-induced heterogeneities in recycled thermoplastic composites

A novel recycling solution for thermoplastic composites (TPCs) was recently implemented. The processing steps comprise shredding of TPC offcuts to flakes of a few centimetres, melting and blending of the flakes in a low-shear mixer, extrusion of a molten mixed dough and subsequent compression moulding in a press. This material and process are similar to the compression moulding of long-fibre thermoplastics (LFTs) that have been in the market for decades, such as glass mat thermoplastics (GMT) or direct-LFT. However, the input material in this recycling route consists of multi-layered woven flakes, which is very different from the pellets or chopped rovings of other LFTs. Process- and material-induced heterogeneities such as fibre orientation, percolation, variation of fibre fraction, or fibre attrition may be different for this new material. The development of this recycling technology and future industrial applications require more confidence in the material and process. The objective of this study is to characterise these heterogeneities for this recycling solution, and compare them to those generated in regular LFTs. It was found that the process- and material-induced heterogeneities of the recycled TPCs are similar to other LFTs, for the aspects listed here: fibre orientation, percolation, variation of fibre fraction and fibre attrition. In comparison to GMT, the effect of the mixing step is particularly noticeable on the local variation of fibre fraction within the panels. Industrial applications of this recycling route will benefit from this similarity, as it improves the confidence in the material and process combination.

Dynamics of Volatile Compounds in Triticale Bread with Sourdough: From Flour to Bread.

Triticale has been suggested for human consumption due to its valuable nutritional composition. The aim of this study was to evaluate volatile compound dynamics in the technological processes of triticale bread and triticale bread with sourdough prepared using Lactobacillus sanfranciscensis based cultures. Two types of sourdough ready-to-use sourdough and two-stage sourdough were used for bread making. Triticale bread without sourdough was used as a control. Volatile compounds from a headspace of flour blend, sourdough, as well as mixed dough, fermented dough, bread crumb and crust were extracted using solid-phase microextraction (SPME) in combination with gas chromatography/mass spectrometry. Alcohols, mainly 1-hexanol, were the main volatiles in the triticale flour blend, whereas in the headspace of sourdough samples ethyl-acetate, ethanol and acetic acid dominated. Two-stage sourdough after 30 min fermentation showed the highest sum of peak areas formed by 14 volatile compounds, resulting in substrates for further aroma development in bread. A total of 29 compounds were identified in the bread: in the crumb the dominant volatile compounds were alcohols, ketones, acids, but in the crust—alcohols, aldehydes, furans dominated. The use of two-stage sourdough provided a more diverse spectrum of volatile compounds. Such volatile compounds as ethanol, 3-methyl-1-butanol, 2-methyl-1-propanol, 2-hydroxy-2-butanone, 2-methylpropanoic acid, and acetic acid were identified in all the analysed samples in all stages of bread making.

Effect of sourdough starter and fungal proteases on gluten content and sensory properties of tarhana

SummaryIn this study, gluten degradation during prolonged tarhana fermentation was monitored in a traditional dough as well as in dough containing sourdough starter, peptidase additives and combination of both. Gluten content, determined using the sandwich ELISA assay method, was reduced significantly in the first 5 days of fermentation for all formulations. After 30 days into fermentation, approximately 15% and 20% reduction of gluten was observed in the traditional dough and sourdough starter added dough, respectively. In enzyme supplemented formulations, the mean gluten levels were below 20 ppm by 20 days of fermentation. Results showed that proteolytic enzyme addition to the dough mix can potentially render long fermented tarhana a food which conforms to regulations set forth for gluten‐free foods, even though wheat flour is one of the main production ingredients. Sensory evaluation of the 30 day fermented tarhana samples revealed differences in sourness and odour properties of the products.

Changes in Protein Non-Covalent Bonds and Aggregate Size during Dough Formation.

This research investigated changes in the amounts and sizes of monomeric proteins and protein aggregates during dough mixing, with a focus on the contribution of non-covalent bonds in the aggregation of gluten proteins. High protein flour (HF) and low protein flour (LF) were used in this study. As dough mixing progressed from flour to overmixed dough, the total amount of protein aggregates increased while the amount of monomeric protein decreased. Omega-gliadin was the major monomeric protein that decreased in quantity. Interestingly, the amount of larger-sized protein aggregates decreased and that of smaller-sized protein aggregates increased. The amount of gluten protein macro-polymer aggregated through strong non-covalent bonds decreased whereas aggregates formed with weaker non-covalent bonds increased. LF dough behaved similar to HF dough. Large-sized gluten protein aggregates disaggregated due to the weakening of non-covalent bonds and became smaller. Omega-gliadin was incorporated into gluten protein aggregates during dough mixing.

Effect of disulphide bonds and sulphhydryl concentrations on properties of wheat flour

Disulphide bonds and sulphhydryl concentrations were evaluated to determine the effects on rheological, thermodynamic, pasting, and dynamic rheological characteristics of mixed flours. Gluten samples, first treated with sodium sulphite of different concentrations, were added into flour at a 4% level, which had a significant impact on free sulphhydryl, disulphide bonds, and the ratio of the two indices. There was no relevance between the ratio and other parameters except for free sulphhydryl. The mixed flour doughs had reduced water absorption, dough development time, dough stability time as well as degree of weakening (P &amp;lt; 0.05). Disulphide bonds were associated negatively with the rate of starch gelatinisation (C3–C2), peak, and setback and these characteristics were correlated strongly with dough development time, dough stability time, and progressive protein weakening (C2–C1). The stability of starch gelatinisation and cooking stability of mixed flours did not remain significantly different. The larger the concentration of sodium sulphite, the higher the peak, breakdown, final viscosity, and setback values, but there were no significant differences between samples. For all samples, storage modulus and loss modulus increased with increasing scanning frequency. For mixed doughs, the trend lines of moduli decreased with increasing levels of reduction in added gluten. There was no substantial effect on thermal properties of flours.

The Effect of Sea Salt, Dry Sourdough and Fermented Sugar as Sodium Chloride Replacers on Rheological Behavior of Wheat Flour Dough.

The aim of this study was to investigate the effects of formulation factors, sea salt (SS), dry sourdough (SD) and fermented sugar (FS) as sodium chloride replacers in wheat flour on dough mixing, extension, pasting and fermentation rheological properties, evaluated by Farinograph, Extensograph, Amylograph and Rheofermentometer devices. With regard to mixing and extension properties, SS and FS presented a strengthening effect, whereas SD presented a weakening one. SS and FS presented a positive effect on dough stability, energy and resistance, whereas SD presented a negative one. On the Amylograph, peak viscosity increased by SS and FS addition and decreased when SD was incorporated in the dough recipe. During fermentation, dough development and gas production in the dough system increased after SS and SD addition, whereas they decreased after FS addition. Response surface methodology (RSM) was used to investigate the effect of independent variables on the rheological properties of the dough. Mathematical models between the independent variables, SS, SD and FS, and the dependent variables, represented by the rheological values of the dough, were obtained. The best formulation obtained was of 0.30 g/100 g SS, 0.50 g/100 g SD and 1.02 mL/100 g FS addition with a 0.618 desirability value, following Derringer’s desirability function approach. For this formulation, bread quality characteristics were better appreciated than for those obtained for the control sample, in which 1.5% NaCl was incorporated in wheat flour.

Development and Performance Evaluation of a Dough Mixing Machine

In view of the numerous problems encountered with the manual method of mixing, an electric motor gear driven dough mixing machine was designed and fabricated from available local materials using standard engineering principles. A step turned shaft of diameters 16 mm and 32.5 mm was attached to speed reducer gearbox which engaged 1hp, single-phase electric motor to transmit torque required to effectively turn and mix the dough in the bowl. The performance evaluation was carried out, the average mixing time for dough of 3.964 kg was 7.67minutes and average mixing efficiency was 94.6% with a mixing capacity of 31 kg/hour operating at 280 rpm of the agitator shaft blade/ arm. The dough produced using the mixing machine was baked into bread and sensory evaluation was conducted and compared favourably with bread baked through hand mixing of dough at 0.05 level of significance. The results further showed that sample B was most accepted followed by sample A (control). Sample C received the least mean score. However, no significant mean difference among the bread attributes at the 0.05 level except for bread texture where samples A and D differ significantly. The cost of fabrication was ₦67,550.00(147dollars) and result of operating cost analysis on per day basis indicated that the owner of the machine can pay back the capital investment in a period of 359 days (1 year) of continuous production.

PROSPECTS OF USING SPINACH IN PRODUCTION TECHNOLOGY OF CHAPATTI OF WHOLEGRAIN FLOUR

It is urgent to enrich floury products with vegetable magnesium sources. One of such plants is garden spinach – one-year plant, a representative of Spinacia genus. For this aim, there were studied functional-technological properties of wholegrain flour for substantiating preparation in the chapatti technology. Research results demonstrated that barley flour had the most water-absorbing capacity – 400 %, this parameter was almost twice less in rice and wheat flour. The most fat-retaining capacity was inherent to barley flour – 87 %, whereas in the control (highest sort wheat flour) this index was 25 %. Technological parameters of spinach preparation in the chapatti composition have been determined: particles size – 250 up to mcm; optimal amount of introduction of wholegrain flour to the mass – 3 %; swelling process duration after dough mixing – 15–20 min for creating a total spatial structure. The energetic value calculation testifies that the caloric number of chapatti is unessential, comparing with main dishes and is in average 220.0 kcal/100 g. Thus, the use of spinach together with wholegrain flour in chapatti gives a possibility to increase a provision degree of the daily need in main nutritive substances for the human organism. The aim of the work is to develop technologies of new types of culinary products and their introduction at public food enterprises

A rheological approach to 3D printing of plasma protein based doughs

3D-printing, also known as additive manufacturing, is a polymeric processing technique whose use has been increasing strongly in recent decades. Because of its customizing potential, it is being widely applied in a great variety of fields, such as medicine, engineering, microelectronic, or food. The present work was focused on the determination of the rheological properties required for certain protein-based doughs (from blood plasma, pea and soy) to flow adequately during the 3D-printing process. Eventually, the formulations that resulted in conveniently shaped items, i.e., that reproduced the desired pattern, were selected. Using glycerol (Gly) as a plasticizer, the printability of doughs with different porcine plasma protein (PPP) contents was initially tested by rheology methods. Only doughs with a PPP content comprised between 42.5 and 47.5 wt % resulted in a successful printing. Then, part of PPP was replaced by a pea protein concentrate (PPC) or a soy protein isolate (SPI), keeping an overall biopolymer content of 45 wt % within the dough. Mixed doughs were properly printed, up to a PPC or SPI content of 10 or 15 wt % within the biopolymer fraction, respectively, displaying all printable doughs similar textural profiles (low firmness, high adhesivity). The building of printability maps for the protein-based doughs studied emphasizes the importance of controlling the rheological properties of protein-based doughs.

Processing conditions and transglutaminase sources to “drive” the wheat gluten dough quality

Gluten proteins are highly impacting the quality of various gluten-based products, and transglutaminases (TGs) are used to influence the protein cross-linking. In this study we monitored the interplay of “harsh” and “mild” gluten processing for dough mixing and pasta-like sheet production and TGs from a commercial and newly sourced bacteria (SB6). Despite the harshly separated gluten presenting strongly cross-linked proteins in the beginning of the mixing, similar levels of polymerization were achieved at the optimum mixing time but with differences in the secondary protein structure. TG addition increased polymerization in wheat doughs, possibly as a result of increased glutenin polymerization, while gliadins become more soluble with SB6. This enzyme also dramatically increased polymerization in mild gluten. These results show that an adequate investigation when using TGs and gluten from various origins is necessary to adequately predict the quality in various gluten-based products, thus, of great relevance to the food industry. Industrial relevanceCurrently, there is a mounting trend towards the modification of gluten proteins to improve technological features and functionality. In breadmaking, when weak flour (low protein content) is used or general stabilization is desired for technological purposes, additives can be used to stabilize the gluten protein matrix. The use of transglutaminase (TG) has grown in popularity as they promote specific cross-linking between residues of glutamine and lysine in proteins. Another way of improving dough functionality is by increasing the oxidation of disulfide groups by adding gluten which is a co-product of the starch industry. Industrial production of gluten includes the use of heating and shear forces, which may impact gluten dough-forming ability. Thus, increased understanding of the interplay of gluten processing and the impact of choice of the TG origin in gluten dough quality is highly applicable in food industry.

믹싱 속도 변화에 따른 식빵의 품질 특성

믹싱 속도 변화에 따른 식빵의 품질 특성

Metabolite analysis of wheat dough fermentation incorporated with buckwheat.

Dough fermentation represents an important developmental stage in the manufacturing process. In this study, volatile and nonvolatile metabolite analysis were carried out to investigate time‐dependent metabolic changes in the course of wheat dough fermentation incorporated with buckwheat based on gas chromatography–mass spectrometry (GC/MS). A total of 70 nonvolatile metabolites were identified, covering a broad spectrum of polar (e.g., amino acids, sugars, sugar alcohols, and acids) and nonpolar (e.g., fatty acid methyl esters, free fatty acids, and sterols) low molecular weight dough constituents. Meanwhile, sixty‐four volatile metabolites comprising aldehydes, ketones, alcohols, organic acids, aromatic compounds, and furans were identified using solid‐phase micro‐extraction combined with GC–MS. Some differences may exist in the volatile composition between fermented and unfermented dough. Statistical assessment of the nonvolatile data via principal component analysis demonstrated that the metabolic changes during the mixed dough fermentation are reflected by time‐dependent shifts of polar nonvolatile metabolites. And some potential nutritional markers, such as amino acids and sugars, could be developed to optimize and control the industrial dough fermentation incorporated with buckwheat.