Particle Size Of Wheat Flour Research Articles

Effects of molecular characteristics and microstructure of amaranth particle sizes on dough rheology and wheat bread characteristics

The aim of this research is to investigate the molecular features and microstructure of amaranth flour (AF) fractions and their partial replacement effect of wheat flour (WF) on the chemical composition, dough dynamic rheology, technological and sensory characteristics of bread. The microstructure and molecular characteristics of AF were depending on their particle size (PS). When WF replacement increased and PS decreased the composite flour was richest in protein, lipids, and ash, while the moisture and carbohydrates of these flours decreased. Dynamic rheological behavior revealed significant variations depending on PS and replacement level. Bread volume and firmness increased when more than 15% AF from large PS replaced WF, while medium and small PS at 5–15% replacements was increased the loaf porosity. Chroma values decreased and samples became darker when the replacement level increased. Moreover, replacement of WF with various AF fractions impacted bread sensory characteristics, obtaining better acceptance for large and medium PS up to 10%.

Effects of wheat flour particle size on flour physicochemical properties and steamed bread quality.

In this study, differently sized particles of wheat flour (from 52.36 μm to 108.89 μm) were obtained by adjusting the distance between the rolls (0.02, 0.04, 0.06, 0.08, and 0.1 mm) of a heart mill. Results showed that reducing the particle size significantly increased the damaged starch (DS) content. Uniaxial tensile measurement of dough showed that reducing the particle size of wheat flour can effectively increase the maximum tensile resistance, but the extensibility reaches the maximum in samples at medium particle diameter (78 and 66 μm). Additionally, the ratio of dynamic moduli (G″/G′) decreased with a reducing particle size. The results of disulfide bond content, gluten microstructure, showed that finer flour granulation can strengthen the gluten network. The steamed bread (SB) making test showed that SB made from wheat flour of a smaller particle size had a significantly smaller specific volume than that made from a larger particle size. The texture profile analysis showed that with a decrease of wheat flour particle size, the hardness, chewiness of SB increased, the resilience decreased, and there was no significant difference in adhesiveness. Overall, the quality of SB made flour of medium particles (78 μm) is better.

Jet milling conditions impact on wheat flour particle size

Jet milling is an emerging, size reduction technique for producing superfine powders in one-step process. The aim of the present article was the research about the efficiency of jet milling process on the wheat flour micronization. A mathematical power model is proposed to describe the effect of feed rate and air pressure on the final flour particle size and energy consumption. A sample of soft wheat flour was grοund using a jet mill at different feed rate (FR) and air pressure (AP) (2–18 kg/h at 4 and 8 bar, respectively). Τhe decrease in FR and further increase in AP resulted in finer flour reaching the lowest value of 10.62 μm. The energy-size reduction equations revealed that the particle size, as well as the energy consumption, were mainly influenced by FR and to a lower extent by AP. FR of 70% was the limit for energy efficient grinding. Α short grinding at high FR and AP is also preferable as damaged starch content was lower.

Effects of wheat flour particle size on physicochemical properties and quality of noodles.

The effect of particle size on the physicochemical and noodle quality of wheat flours was investigated. Granular wheat flour was ground by adjusting the distance between the rolls (0.02, 0.04, 0.06, 0.08, and 0.1mm) of the flour mill to obtain wheat flour in five different particle sizes. The results showed that milling intensity significantly reduced the particle size and increased the damaged starch content and sedimentation value, but there were no significant differences in protein or ash contents. The reduction of wheat flour particle size significantly decreased the peak viscosity, trough viscosity, final viscosity, breakdown, and setback of the blends, while there were no significant differences in pasting temperature. Stress relaxation characteristics indicated that as the particle size of wheat flour decreased, dough hardness increased. The noodles made from wheat flour with a smaller particle size had a higher water absorption rate and cooking loss rate. Textural profile analysis parameters showed that as the particle size of wheat flour decreased, the hardness, chewiness, recovery, and adhesiveness of noodles showed increasing trends, and there was no significant difference in elasticity. In summary, it is found that the quality of the noodles made by sample C (D50 : 78.47µm) is better.

Visible/shortwave near infrared spectroscopy and hyperspectral scattering for determining bulk density and particle size of wheat flour

Particle size and bulk density are two important fundamental properties of food powder that directly affect processing and final product quality. The objective of this study was to evaluate and compare two optical sensing methods, i.e. visible/shortwave near infrared spectroscopy and hyperspectral scattering, for bulk density determination and particle size classification of wheat flour. Hyperspectral scattering images over the spectral region of 500–1000 nm and visible/shortwave near infrared reflectance spectra covering the spectral region of 400–1000 nm were acquired for 474 wheat flour samples. Partial least squares regression and discriminant analysis models for visible/shortwave near infrared spectra and mean spectra extracted from the hyperspectral scattering profiles were developed for determining the bulk density and classifying the particle size, of wheat flour samples. Hyperspectral scattering gave much better prediction results for bulk density, with the r2 (the coefficient of determination for prediction) value of 0.87 and the root mean squares error of prediction value of 30.20 mg ml−1, compared with the r2 of 0.55 and root mean squares error of prediction of 57.13 mg ml−1 obtained by visible/shortwave near infrared spectroscopy. Moreover, hyperspectral scattering resulted in 98.2% classification accuracy for particle size, versus 96.8% by visible/shortwave near infrared spectroscopy. This research suggested that hyperspectral scattering is more suitable than visible/shortwave near infrared spectroscopy for bulk density determination and particle size classification of food powder.

Sieving fractionation and jet mill micronization affect the functional properties of wheat flour

The particle size of wheat flour has a significant effect on its functional properties. Three fractions of roller milled wheat flour were obtained using sieving: a coarse fraction (CF) with d50>200μm, a middle fraction (MF) with 100μm<d50<200μm and a fine fraction (FF) with d50<100μm. An extra fine fraction was received by pulverizing CF in a jet mill (JCF). Particle size volume distributions were determined and further samples characterisation included: chemical composition, water holding capacity (WHC), starch damage, swelling capacity, and slurries viscoelasticity. CF presented bimodal granules’ volume distribution containing many agglomerates of irregular shape. The fine fractions differed significantly. JCF contained spherical granules, whereas FF irregular granules’ fragments with a few free starch granules. JCF presented the highest WHC and granules swelled fast (up to 75°C) with a great soluble solids leakage. FF presented a delayed gelatinisation and low elasticity, indicating a weak structure.

Influence of Allelic Variations of Glutenin and Puroindloine on Flour Composition, Dough Rheology and Quality of White Salted Noodles from Korean Wheat Cultivars

Allelic variations in glutenin and puroindolines of 26 Korean wheat cultivars were evaluated to determine their effects on the physicochemical properties of flour and quality of white salted noodles. Cultivars carrying Pina-D1b and Pinb-D1b exhibited a coarser particle size of wheat flour and a higher ash and damaged starch content than those with Pina-D1a and Pinb-D1a. Glu-B1b, Glu-D1f, Glu-B3d and Pina-D1a alleles exhibited lower protein content than other alleles. Glu-A1c, Glu-B1b, Glu-D1f Glu-B3d, Glu-B3i and Pinb-D1b alleles appeared to be related to a lower SDS-sedimentation volume than other alleles. In dough rheological properties, Glu-A1a and Glu-D1d alleles showed a longer mixing time on the mixograph and maximum dough height but Glu-A3e and Glu-B3i alleles had a lower mixing time on the mixograph and a lower maximum dough height than other alleles at Glu-1 and Glu-3 loci. Regarding the quality of white salt noodles, about 10% of the variations in the hardness of cooked noodles were explained by Glu-A1 and Glu-B3 loci. Hardness rankings of cooked noodles were Glu-A1a > Glu-A1c > Glu-A1c at the Glu-A1 locus. Glu-B3h showed higher cooked noodle hardness (5.10 N) than other alleles at the Glu-B3 locus (< 4.66 N).

Soft wheat instead of hard wheat in pelleted diets results in high starch digestibility in broiler chickens

1. The aim of the experiment was to re-examine variations in digestibilities of food components in 3-week-old broiler chickens fed on pelleted diets based on wheats differing in lipase activity and hardness. Fourteen wheat (Triticum aestivum) samples, each from a different cultivar, were included at 550 g /kg in 14 different diets given to male Ross broiler chicks from 7 d of age. The other main ingredients consisted of soyabean meal (353 g /kg) and rapeseed oil (55 g /kg). A 15th diet containing durum wheat (Triticum durum) was also tested. 2. Hardness of wheats (Triticum aestivum) varied between 14 (very soft) and 88 (very hard), and lipase activity of wheats varied from 1 to 13·1 (relative scale). No significant correlation was found between in vitro viscosities and other parameters such as hardness, particle size of wheat flours and lipase. Hardness was correlated with the mean particle size of wheat flours and durability of pellets. 3. Individual lipid digestibilities were negatively correlated with in vitro viscosities of wheats. 4. Individual starch digestibilities were negatively correlated with wheat hardness, particle size of wheat flour before pelleting, and pellet durability. The ratio of measured AMEN to predicted AMEN was also negatively correlated with wheat hardness. Simple regression calculation showed that a 100-point increase in wheat hardness resulted in a 3% decrease in the AMEN value of diets. Multiple regression calculation showed the food/gain ratio (d 10 to d 21) to be positively related to wheat hardness and negatively related to pellet durability. 5. Wheat lipase activity was positively correlated with individual starch digestibility, which was the reverse of a result obtained in a previous experiment. Thus, wheat lipase activity did not seem consistent for predicting starch digestibility and AMEN values. 6. Among all wheat samples, durum wheat showed the highest protein content and the lowest content of water-insoluble cell-wall. Starch digestibility of durum wheat tended to be lower than that of other wheats (0·916 vs 0·936). However, no significant difference in AMEN was observed between the durum wheat sample and other wheats. 7. Gut morphometric data measured at d 24 did not show significant differences between dietary treatments.