Flour Particle Size Research Articles

The effects of wheat cultivar, flour particle size and bran content on the rheology and microstructure of dough and the texture of whole wheat breads and noodles

The rheological properties and microstructure of doughs, and the texture properties of whole wheat breads and noodles were investigated. The gluten strength of doughs were discriminated due to wheat cultivar. Reduced flour particle size led to the doughs with a stronger gluten strength (i.e., smaller C2), lower degree of starch retrogradation (i.e., smaller C5), and longer relaxation time (i.e., larger n values). Firmer crumb of breads were prepared by flours with smaller particle size. With increased bran content, the gluten strength of dough weakened (i.e., increased C2), the development and relaxation time of dough and the degree of starch retrogradation decreased (i.e., decreased C1 time, n values and C5), the dough structure became more porous, and the product texture appeared to be firmer. As such, outcomes from this research will provide a practical guidance for the bakery industry to improve the consumer acceptability of whole wheat products.

The Possibility of Replacing Wet-Milling with Dry-Milling in the Production of Waxy Rice Flour for the Application in Waxy Rice Ball.

Due to the large consumption and discharge of water in wet milling, dry-milling is an alternative to produce waxy rice flour. The physical properties and sensory characteristics for preparing waxy rice balls in dry-milled waxy rice flour were compared in this study. The results showed that the damaged starch content increased significantly with the particle size of dry-milled flour, which decreased from 160 to 30 μm. The reduction in particle size increased the pasting viscosity of waxy rice flour, which further improved the stretch ability of dough and increased the viscoelasticity of the rice ball. The increase in damaged starch content directly led to a significant increase in the solubility of dry-milled flour, thereby increasing the freeze cracking rate of the rice ball and reducing its transparency, resulting in a decline in quality. In comparison with wet-milled waxy rice balls, dry-milled waxy rice balls made from rice flour in the range of 40 μm to 60 μm particle size had a similar texture and taste to that of wet-milled ones, moderate freeze cracking rate and better storage stability, as well as a stronger aroma of waxy rice that the consumer favored. GC-MS analysis showed that the content of key aroma compounds, such as grassy and fruity, noted nonanal in dry-milled flour, was 15-30% higher than that in the wet-milled depending on the difference of waxy rice variety. In conclusion, dry-milled waxy rice flour with a particle size in the range of 40 μm to 60 μm could be a candidate to replace wet-milled flour in the preparation of a waxy rice ball.

Various admixtures to mitigate the long-term strength retrogression of Portland cement cured under high pressure and high temperature conditions

In order to investigate the problem of long-term strength retrogression in oil well cement systems exposed to high pressure and high temperature (HPHT) curing conditions, various influencing factors, including cement sources, particle sizes of silica flour, and additions of silica fume, alumina, colloidal iron oxide and nano-graphene, were investigated. To simulate the environment of cementing geothermal wells and deep wells, cement slurries were directly cured at 50 MPa and 200 °C. Mineral compositions (as determined by X-ray diffraction Rietveld refinement), water permeability, compressive strength and Young's modulus were used to evaluate the qualities of the set cement. Short-term curing (2–30 d) test results indicated that the adoption of 6 μm ultrafine crystalline silica played the most important role in stabilizing the mechanical properties of oil well cement systems, while the addition of silica fume had a detrimental effect on strength stability. Long-term curing (2–180 d) test results indicated that nano-graphene could stabilize the Young’s modulus of oil well cement systems. However, none of the admixtures studied here can completely prevent the strength retrogression phenomenon due to their inability to stop the conversion of amorphous to crystalline phases.

Study on Water Resistance of Polypropylene Based Wood-Plastic Composites Used in Building

This research was aimed at studying the preparation of polypropylene based wood plastic composite material by twin-screw extrusion. The effects of the addition of the maleic anhydride (MAH) and wood flour on WPC properties were evaluated. WPC with 4, 5, 6, 7, 8, 9, 10 wt% of MAH contents were prepared. The mechanical properties and water resistance of WPC were studied. The result showed that with the increasing of MAH, the tensile strength of WPC increases at first and then decrease, and water absorption reduced by 39%. After immersing in water for 24 h, the tensile strength of WPC decreases but the impact strength increases, and with the increasing of MAH, the reducing extent of tensile strength increases, but the improvement extent of impact strength gradually decreases. When the MAH content exceeds 8 wt%, the impact strength of dried WPC samples (dried for 24 h) can be recovered basically. WPC with 10, 20, 30, 40 wt% of wood flour contents were prepared. The result showed that with the increasing of wood flour, the tensile strength of WPC increases at first and then decreases, the impact strength decreases, and water absorption increased by 62%. When the wood flour content exceeds 10 wt%, the impact strength of dried WPC samples can only recover partially. WPC containing different wood meal sizes was prepared. The result showed that with the decreasing of wood flour particle size, the water absorption of WPC increases obviously. The impact strength of dried WPC samples is higher than that of unsoaked WPC, when the particle size of wood flour is 60 meshes. It can be seen from the SEM photos that the distance between the wood powder fibers becomes larger after 24 h of WPC soaking in water. The finer the wood flour, the easier it is to aggregate in WPC.

Addition of Amaranth Flour of Different Particle Sizes at Established Doses in Wheat Flour to Achieve a Nutritional Improved Wheat Bread.

Amaranth is an underutilized pseudocereal that can be used to supplement wheat flour (WF) in order to improve the nutritional quality of bread. Bread digestibility is impacted by particle size which produces different nutritional properties. This research aims to evaluate the baking characteristics of optimal wheat−amaranth composite flour for each studied amaranth flour (AF) particle size at doses previously established based on an optimization process and to characterize from a physical, textural, nutritional, and sensorial point of view the obtained bread. The results revealed that the optimal wheat−amaranth composite flour with medium and small particle size, respectively showed a slightly lower α-amylase activity, while dough development time was significantly higher compared to the WF. A significant (p < 0.05) decrease was observed in the elasticity, deformation energy, and dynamic rheological parameters of the optimal composite dough for all the particle sizes, whereas fermentation parameters showed higher values compared to the control, indicating the ability of the gluten structure in large, medium, and small particle sizes of AF to hold the gas and to expand without collapsing. The physical, textural, and especially nutritional characteristics of the optimal WF-AF bread were enhanced. The sensory evaluation results revealed high scores (8.70) for the acceptability of optimal bread with a medium particle size as compared to wheat bread (8.25). The protein and ash content of the optimal breads with large, medium, and small AF particle sizes, respectively, increased significantly, from 8.92 to 10.58%, and 0.82 to 0.99%, respectively, relative to the wheat flour bread (8.35% and 0.72%, respectively). The mineral content was up to two times higher in the optimal breads compared to wheat flour bread. The findings generated from this study are helpful in bakery industry for designing products with enhanced nutritional properties and for introducing new products to the market.

Development of a gluten free bread enriched with faba bean husk as a fibre supplement

Faba bean husks (FBH) are a high-fibre waste product of faba beans and are primarily used as animal feed with the potential of becoming a fibre supplement. In this study, different levels and particle sizes of FBH flour were used to enhance the fibre content of gluten free bread. Bread properties were evaluated by measuring specific volume, colour (crust and crumb), and crumb texture. The sensory characteristics of breads were assessed by a group of untrained panellists (n = 66) on appearance, aroma, flavour, texture, aftertaste, willingness to buy, and overall acceptability using a nine-point hedonic scale. Volume of bread was affected by the level and particle size of FBH added. Texture analysis showed the importance of level of FBH, and of its particle size in establishing hardness, gumminess, and chewiness (p < 0.05). The added FBH influenced the colour of the crust and crumb. Two formulations of FBH-enriched gluten free bread (particle sizes of 212–300 μm at 5% wheat flour weight substitution, and particle sizes of smaller than 212 μm at 15% wheat four weight substitution) increased the fibre content of the bread, while had no negative impact on sensory evaluation in comparison to control treatment (p < 0.05).

The influence of dough kneading time and flour particle size distribution on white bread structure, glycemic response and aspects of appetite.

White bread is widely consumed in many countries despite being a high-glycemic index (GI) food. It has been shown that the "food matrix effect" may help with diabetes and obesity management through lowering GI and appetite. This study aimed at investigating the effects of dough kneading time and flour particle size on white bread structure, glycemic response, and aspects of appetite. A two-phase randomized cross-over design was used in 10 healthy subjects over the course of 2h. In phase 1, Texture Profile Analysis (TPA) attributes, Scanning Electron Microscope (SEM) image, glycemic response, and appetite aspects of white bread made with a 15-mindough kneading time (K15) were compared with white bread made with a 10-mindough kneading time (K10). In phase 2, TPA, SEM image, glycemic response, and satiety score of white bread made with coarse flour (CF) were compared to white bread made with fine flour (FF). With increasing hardness (force required to compress a food between the molars to a given deformation), total blood glucose IAUC in K15 (IAUC=119±12; GI=66) was significantly (p<0.05) lower than in K10 (IAUC=154±10; GI=81). No marked difference was observed between K15 and K10 on aspects of appetite except for hunger. There was no significant (p>0.05) difference in glycemic response between CF (IAUC=126±18; GI=64) and FF (IAUC=147±12; GI=81). Similarly, no discernible difference in satiety between CF and FF. Changes in processing conditions can improve blood glucose response relalated to white bread consumption.

The role of hydrothermal treatment (steaming and tempering) parameters on oat groat, flake and flour properties

The role of hydrothermal treatment (steaming and tempering) parameters on oat groat, flake, and flour properties was studied by using experimental design and response surface modelling approach. The modelled properties were oat groat hardness, oat flake hardness, and oat flour particle size milled from oat groats and oat flakes. In the design of experiments, the studied factors were moisture content, temperature, and duration of the hydrothermal treatment using the central composite face-centred design (CCF). Three untreated oat groat cultivar samples with varying native groat hardness were studied. Among the studied factors, tempering temperature influenced both groat hardness and flour particle size in all samples. High temperature led to fragile groats and fine flours, while low temperature resulted in hard groats and coarse flours. The treatment parameters affected groat and flour properties in a generally similar way, but sample-specific differences remained in groat hardness and flour particle size after identical treatments. In the sample with the softest native groats, also the moisture content influenced groat hardness and flour particle size. Our results suggest that with a proper selection of the native groats and by adjusting the hydrothermal treatment parameters, the milling properties of oat could be optimised for specific uses.

Improvement of the barrier and mechanical properties of environmentally friendly mango kernel flour/glycerol films by varying the particle size of mango kernel flour

The development of environmentally friendly films based on glycerol and different sizes of mango kernel flour particles (MKF), ranging from 100 to 600 µm, is reported. The casting solution method was used to produce the films, using distilled water as the solvent. The mechanical, morphological, barrier, surface, optical, wettability and biodegradability properties of the films were assessed. The mechanical analysis revealed that smaller particles lead to superior mechanical performance in terms of tensile strength, elastic modulus and elongation at break, achieving an elongation at break of 18.1 % for the films with the smallest particle size (100 µm). These results were confirmed by field emission scanning electron microscopy (FESEM) images of the films, where the gap between the mango kernel particles and the glycerol matrix is practically non-existent in films with the smallest particle size (100 µm). On the other hand, it was observed that as the particle size decreased, the barrier properties improved, showing a decrease in water vapor permeability rate (WVPR). With respect to antioxidant properties, it was observed that the films showed strong antioxidant activity, as assessed by 2,2–diphenyl–1–picrylhydrazyl (DPPH) inhibition above 90 % for all films after 1 week. Finally, MKF films proved to be completely biodegradable, with a 100 % of disintegration after 4 weeks of incubation time in compost soil, with the smallest MKF particle size films exhibiting the highest disintegration rate. • Smaller MKF particle size in the films leads to superior mechanical, barrier, antioxidant and biodegradability properties. • MKF/glycerol films possess strong antioxidant capabilities based on DPPH inhibition tests. • MKF/glycerol films present complete disintegration at 21 days of incubation in compost soil.

Particle size distribution control during wheat milling: nutritional quality and functional basis of flour products—a comprehensive review

SummaryWheat (Triticum aestivum L.) is one of the most important food grains worldwide, mainly consumed in the form of wheat flour or flour‐based foods. Milling reduces the particle size of wheat grains or wheat endosperm, which strongly affected the physical and chemical properties of wheat flour and subsequent product characteristics. In this paper, the differences in physical and chemical properties of wheat flour due to its particle size distribution, the sources of the differences and the applicability of flour products were reviewed. Furthermore, the modern wheat milling process, the mathematical modelling, and mechanical modification of wheat milling process in recent years were introduced. The research prospect of the influence of milling process on the formation of particle size and quality of wheat flour was put forward.

Understanding the Mechanism of How Pulsed Electric Fields Treatment Affects the Digestibility and Characteristics of Starch in Oat Flour

The objective of this study was to evaluate the effect of pulsed electric fields (PEF) on the in vitro starch digestibility properties of oat flour. A wide range of PEF process intensity was investigated (electric field strength between 2.1 and 4.5 kV/cm and specific energy inputs between 52 and 438 kJ/kg using 20 μs square wave bipolar pulse at 100 Hz). The results revealed that PEF applied at a high electric field strength and energy &lt;216 kJ/kg was favourable in slowing down the rate of starch digestibility (by 48%) during in vitro gastrointestinal digestion. This is accompanied by a significant decrease (from 15% to 7–10%) in the proportion of rapidly digestible starch (RDS) and a significant increase (from 77% to 84–85%) in resistant starch (RS) fraction. The application of PEF at energy level &gt;421 kJ/kg at any field strength intensities raised the RDS (from 15% to 19–20%), but the rate of starch digestion was not affected (maintained at 3.3–3.7 × 10−2 min−1 vs. untreated at 3.8 × 10−2 min−1). Further analysis of the structure, particle size, and thermal stability of PEF-treated oat flour through fractionation into three distinct flour segments revealed that PEF could cause major modifications in the particle size, damage and aggregation of starch granules, and destruction of the long- and short-range ordered structures of starch. Data gathered in this study indicate that PEF treatment can be a reliable strategy to modulate the in vitro starch digestibility of oat flour, either by reasonably slowing down the digestion rate or enabling a slightly higher amount of starch to be readily accessible by digestive enzymes without affecting the digestion rate.

INFLUENCE OF DRY HEAT TREATMENT ON ANTIOXIDANT ACTIVITY AND TOTAL POLYPHENOL CONTENT OF DIFFERENT SORGHUM PARTICLE SIZES

Sorghum is the fifth most used cereal and contains many bioactive compounds which enhance the antioxidant capacity. The aim of this study was to investigate the antioxidant capacity and the total phenolic content by applying different organic solvents and extraction times on sorghum grain at different particle sizes which were subjected dry heat treatment. The antioxidant capacity values varied between 53.5% to 100%, and the total phenols content ranged from 6.58 mg GAE/g to 54.90 mg GAE/g for the sorghum flour particles sizes, indicating a significant increase when the dry heat treatment was applied. From the solvent used point of view, it can be seen a rise in antioxidant capacity and concentration of total phenols extracted in the following order: methanol &gt; water &gt; ethanol. Also, when the particle size of sorghum flour decreased and extraction time increased, the values of antioxidant capacity and total polyphenols components increased. This study revealed the potential of different sorghum particles size from the total polyphenols and antioxidant capacity point of view and to use them as ingredients to raise the shelf life of food products.

Black rice flour‐induced changes in gluten conformation in fresh, pre‐fermented and frozen dough

SummaryBlack rice flour greatly enriches the nutrition of flour products, and also alleviates the quality deterioration of frozen dough to a certain extent, but the gluten‐influenced mechanism remains unclear. The effects of black rice flour with different particle sizes on protein molecular weight distribution, secondary structure, fluorescence characteristics, thermogravimetric properties, and chemical interaction of the fresh dough (FD), pre‐fermented dough (PD), and thawed dough (TD) were investigated. The addition of black rice flour resulted in the breaking of disulfide bonds in the FD and an increase in the content of total SDS‐extractable protein. However, the depolymerization of large glutenin polymers in the PD and TD of the composite flour system was lower than wheat flour system, especially in the dough with small particle size black rice flour. As the particle size of black rice flour decreased, the intermolecular force of the composite flour dough system is more prominent, of which the hydrophobic interaction force contributes the most considerable value. In addition, TD in the composite flour system has less weight loss than that of wheat flour system. Therefore, adding black rice flour reduced the deterioration of gluten protein, and the small particle size of black rice flour showed advantages.

Effect of rice flour ultrafine particle size on β-glucanase inactivation by microwave treatments and pasting properties in treated flours

The main problem in developing gluten-free products enriched with β-glucans (BG) is the hydrolysis they suffer due to the endogenous β-glucanase content of raw materials. The depolymerization causes a decrease in the molecular weight and viscosity, which is the most important parameter related to the health claims of BG. Hence, it is necessary to inactivate the β-glucanase. Therefore, this study aimed to inactivate the β-glucanase activity present in rice flour (Indica variety) with fine particle size using the microwave (MW) hydrothermal treatment method. The rice flour was conditioned at three different humidities 13, 16, 19 and 25%. Samples of 50 g were subjected to different microwave treatments 1, 2, 4 and 8 min, at 900 W power at 20 seconds intervals of treatment and 1-minute rest. The effect of particle size on inactivating the β-glucanase activity and the effect of MW treatment on the flour pasting property were also studied. The inactivation process followed a first-order kinetic response, and the apparent rate constant of thermal inactivation increased exponentially with the moisture content (M) of the flour, according to the equation -0.02t·exp (0.19·M) (R2 = 0.987). Among the treatments employed 4 min treatment at 25% initial M was found effective for complete β-glucanase inactivation. The effect of flour particle size did not show a significant (p&gt; 0.05) difference on the efficiency of β-glucanase inactivation. Keywords: particle size, β-glucans, rice flour, microwave treatment, β-glucanase activity.

Effects of Jet Milling on the Physicochemical Properties of Buckwheat Flour and the Quality Characteristics of Extruded Whole Buckwheat Noodles.

The effects of jet milling on the physicochemical properties of buckwheat flour and the quality characteristics of extruded whole buckwheat noodles (WBN) were investigated in this study. The results reveal that the application of jet milling significantly reduced the particle size of buckwheat flour. As a result, the damaged starch content, water solubility index, water absorption index and swelling power of buckwheat flour all increased. It was worth noting that moderately ground buckwheat flour powder (D50 = 65.86 μm) had the highest pasting viscosity and gel hardness. The breaking rate and cooking loss of extruded whole buckwheat noodles made from the above powder were reduced by 33% and 16%, respectively. Meanwhile, they possessed the highest lightness and firmest network structure. Jet milling increased the soluble dietary fiber (SDF) content from 3.45% to 4.39%, and SDF further increased to 5.28% after noodle extrusion. This study was expected to provide a reference for exploiting high-quality gluten-free noodles from the perspective of milling.

Effect of particle size of ragi flour on physico-chemical and sensory profile of ragi mudde

Ragi mudde is a traditional food made with ragi (finger millet) flour. It is a major source of carbohydrate, calcium, iron, protein and well balanced amino acids and is a staple diet in rural parts of South India. The consistency of Ragi mudde depends on the particle size of its flour and water uptake during cooking. Ragi flour (RF) particle size was determined by particle size analyzer. The physical properties of Ragi mudde such as bulk density (RF), water uptake during cooking ( Ragi mudde ) were also measured. Traditionally cooked Ragi mudde was characterized for color and texture by sensory and instrumental analysis. The coarseness or fineness of the RF was found to have tremendous effect on the physical and sensory profile of Ragi mudde , such as hardness, stickiness, cooking quality, color and texture. Ragi flour with different particle size, viz., 150 (S1), 300 (S2), 450 (S3), 600 (S4) and 750 (S5) µm were used in the preparation of Ragi mudde . Color values, expressed as L*, a* and b*, showed significant difference among the samples. Texture profile analysis (TPA) of the samples showed positive correlation to hardness and stickiness. The results of quantitative descriptive analysis (QDA) revealed that the samples S4 and S5 scored high for the overall quality. Considering the above parameters, RF with particle size 600-750 µm, suits best and ideal for the preparation of Ragi mudde .

Study on sugar-free cupcake

Cupcakes are small loaves baked in thin paper or plastic bowls. As with the best loaves, icing and decorating are optional. A typical gorgeous woman employs basic elements such as fat, carbohydrate and flour (Sorghum crushing and Wheat crush into fine grains). The recipe works well for layer loaf that may be used to make cupcakes. Typically, muffin tins with a non-stick surface composed of metal, silicon rubber, stoneware or another material are used to bake cupcakes. Muffin tins typically contain six cups. A typical cup has a diameter of 3 inches (76 mm) and can carry 4 ounces. Cupcake batter can be flavour-infused or have other ingredients like raisins, cherries and nuts included in. Wheat flour can be partially replaced by sorghum flour. Sorghum flour's particle size and shape frequently make baked goods like cakes and bread seem grittier. However, several non-gluten-free baked goods, such as flatbreads, cakes, muffins, cookies and biscuits have been produced using sorghum and wheat flour mixes. Gluten, non-starch polysaccharides and lipids are among the many different compounds found in wheat flour and they all have a significant influence on both the raw material's processability and the quality of the finished goods [15]. Large amounts of carbohydrate and other ingredients including proteins and lipids are present in wheat flour, which impacts the characteristics. Only (1% to 3%) of the wheat flour's overall composition is made up of lipids. Free and bound lipids are the two categories into which they may be divided [44].

Utilization of Wood Flour from White Oak Branches as Reinforcement in a Polypropylene Matrix: Physical and Mechanical Characterization

Compared to other fibrous materials, plant fibers can act as a reinforcement in plastics due to their relatively high strength and rigidity, low cost, low density, biodegradability, and renewability. In this context, this study examines the effect of the particle size and content of white oak wood flour (Quercus laeta Liemb), obtained from its branches, on the properties of commercial polypropylene. In Mexico, wood from the branches of Quercus laeta Liemb is barely utilized despite its abundance and viability. The main objective of this study is to demonstrate that this waste material can be exploited to prepare useful materials, in this case composites with competitive properties. Tensile and flexural tests, as well as impact strength and melt flow index were evaluated. In addition, density and water absorption capacity were also tested. Results showed that the water absorption increased with the incorporation of wood particles. Mechanical properties were strongly influenced by particle content. A reduction in elongation and strength was observed, while Young’s modulus and flexural modulus increased with the incorporation of wood particles. Impact strength increased with particle size and particle content.

Effect of black soybean flour particle size on the nutritional, texture and physicochemical characteristics of cookies

In order to enrich the cookies' nutrition, black soybean was used to develop cookies, and the effect of its particle size on the characteristics of cookies was analysed. The results showed that the chemical score of black soybean cookies (12.02–13.24) was significantly greater than that of wheat flour cookies (9.14), which was significant for improving cookies’ nutrition. The cookies thickness decreased when the particle size of black soybean flour decreased, but the spread ratio increased. The addition of black soybean flour greatly decreased the lightness of the cookie from 74.79 to 51.32. The decrease in particle size affected texture of cookies, especially for hardness and fracturability, they increased from 12.22 to 13.86 N, and decreased from 1.26 to 1.02 g, respectively. The addition of black soybean remarkably increased the slowly digestible and resistant starch, especially for cookies made from coarse black soybean flour, up to 50.22% and 26.10%, respectively. The black soybean flour enhanced the binding force of free water in cookies system, giving cookies a higher crispness. Based on physicochemical properties and nutrition analysis, using black soybean flour to develop cookies is feasible in industrial practice. And from sensory analysis, superfine black soybean flour was preferred for cookies production.

Comparisons between flour qualities produced by three different mills: buhler, quadrumat, and industry mills

Three types of mills (Buhler, Quadrumat, and industry mill) have been used to determine the effect of mill type on the quality of the produced flour. Quadrumat and Buhler mills are usually used to produce flour at a laboratory level. Flour quality has been determined physically, chemically, and rheologically. Results showed that the particle size of flour produced by Buhler mill (FPB) was finer (mostly less than 132 μm) than other produced flour, while flour produced by Quadrumat mill (FPQ) had 8% particle size bigger than 50gg, which is more than Iraqi accepted limit (5%). The moisture content of FPQ exceeded the moisture content limit (14%). While, all flour produced by industry mills (FPI) was within the Iraqi standard in term of particle sizes and moisture content. Gluten content of FPB was higher than other produced flours; however, most increments were not significantly different. The results also showed that using different mills has no clear effect on the gluten index and alpha-amylase activity. Farinogram and extensogram results showed that FPQ was stronger than other produced flour followed by FPI. In conclusion, the quality of FPQ was closer to the quality of FPI, however, Quadrumat mill needs to be adjusted to produce flour with finer particle sizes and lower moisture content. The Buhler mill, on the other hand, needs to be adjusted to produce flour with bigger particle size. Both laboratory mills (Quadrumat and Buhler) need to be adjusted to produce flour that expresses FPI correctly.