Flour Particle Research Articles

Physicochemical properties of jet milled wheat flours and doughs

The aim of this study was to evaluate the physicochemical properties of white wheat flour pulverized by jet mill and the rheological behavior of the resultant doughs. A commercial coarse (control) wheat flour with d50 < 75 μm (CON) was micronized by jet-mill under two different feed rates, resulting in fine and ultrafine flour preparations with d50 < 21 μm (JM1) and d50 < 12 μm (JM2), respectively; d50 value was reduced with decreasing feed rate. The levels of damaged starch (5.3–11.5% as is) and water soluble arabinoxylans (0.4–0.5% d.b.) increased (p < 0.05) with reduction of flour particle size, while no changes in apparent peak molecular weight, determined by HPSEC–RI, and primary structure of the AXs (e.g. degree of branching) estimated by 1H NMR, were noted upon flour jet-milling. Starch gelatinization properties and dough rheological behavior of CON, JM1, JM2 flours and a mixture (CON:JM1 1:1), covering a particle size range applicable to actual breadmaking processes, were studied. Calorimetry of aqueous flour dispersions (flour:water 30:70 w/w) showed a decrease in starch gelatinization enthalpy of the flours containing jet mill fractions compared to control flour. For the jet mill flours, the creep-recovery test of doughs (flour:water 56:44) revealed an increase (p < 0.05) in resistance to deformation, elasticity and zero shear rate viscosity. Additionally, Texture Profile Analysis (TPA) and compression - stress relaxation testing after lubricated squeezing flow (LSF) revealed that with decreasing flour particle size, the doughs become harder with higher consistency, more sticky and gummy and exhibit longer half relaxation time, lower relaxation rate and higher elongational viscosity.

Comparison of pregelatinization methods on physicochemical, functional and structural properties of tartary buckwheat flour and noodle quality

The microstructural, physicochemical, nutritional, functional and protein structural properties of buckwheat flour as affected by different pregelatinization treatment including roasting, steaming, extrusion, boiling and microwave before milling were investigated. Scanning electron microscopy studies showed that flours treated by boiling and extrusion displayed more swollen and more compacted flour particles than raw, roasted and microwave treated flours. Native buckwheat flours displayed lower values of gelatinization degree, swelling power and hydration capacity than pretreated flours, while pretreated flours were darker and more reddish than native flour. Regarding the functional ingredients, native flours have more total flavonoid, rutin and content than quercetin treated flours with the exception of steaming and extrusion. The different pregelatinization treated buckwheat flours showed a remarkably decrease in their viscosities as revealed by rapid visco analyzer (RVA). Furthermore, the primary structure of buckwheat protein did no change with different pretreatments, whereas the extrusion treatment seemed to induce a conjugation between protein molecules. The pregelatinized buckwheat flours were also observed to have potential for producing high quality and functional noodles.

Textural, Color, Hygroscopic, Lipid Oxidation, and Sensory Properties of Cookies Containing Free and Microencapsulated Chia Oil

Encapsulation of chia oil might protect omega-3 and omega-6 from lipid oxidation when producing baked foods. However, the actual gain in stability given by chia oil must be determined. In this work, chia oil or chia oil-loaded microparticles were added to a cookie formulation in order to evaluate the ability of the microcapsules in protecting chia oil from deterioration. Texture, color, water sorption isotherms, and sensorial properties were also evaluated. A hot homogenization technique was used with carnauba wax as an encapsulant, and the freeze-dried microparticles were incorporated into the cookie dough. Principal component analyses were carried out to evaluate lipid oxidation using the medium infrared spectra of the lipid fraction extracted from the baked cookies. It was found that the microencapsulated chia oil was better protected from oxidative deterioration during baking compared to the sample containing non-encapsulated chia oil. Textural analysis showed that chia oil (free and microencapsulated) acted as a coating on the wheat flour particles. Control cookies (no chia oil loaded) presented a more hydrophilic character. In the case of oil-loaded samples (free and microencapsulated), the isosteric heat of sorption behavior indicated an initial swelling step of the food polymers, resulting in the exposure of sorption sites of higher binding energies not previously available, and that this is because of the wheat particles being covered by the chia oil and the solid lipid microparticles. Furthermore, food acceptability did not change when the oil-loaded microparticles were added to the cookie formulation.

Characterizing whole‐wheat flours produced using a commercial stone mill, laboratory mills, and household single‐stream flour mills

Background and objectivesOne hard wheat and one semi‐hard wheat were milled on commercial, laboratory, and household‐scale flour mills with rotating elements ranging from 0.1 to 1.0 m in diameter and speeds ranging from 65 to 40,000 rpm. The aim of the study was to assess and compare the quality of the flour from each of mills.FindingsPasting viscosities, Farinograph development time and stability, and loaf volumes (LVOL) were all markedly influenced by whole‐wheat flour particle size, which differed markedly between mills. LVOLs were acceptable using the flours produced by all the mills. Best flour quality came from the three mills that produced the finest whole‐wheat flour. Of these, the superior flour came from the 1.0‐m‐diameter Osttiroler stone mill. This mill produced whole‐wheat flours with more optimal levels of starch damage and higher water absorption than did the smaller mills. There was no evidence of degradation of gluten functionality even at a flour temperature of 51°C.ConclusionsThe mill used affected almost all flour quality traits. However, the characteristics of the wheat applied to the mill were the dominant influence on flour functionality. Starch damage may better indicate milling severity than the heat generated during the milling process.Significance and noveltyThis is the only study, that we know of, on the comparative performance of household‐scale flour mills. The study also presents an alternative way of visualizing particle size distributions of flours.

A study of factors influencing the water absorption capacity of Canadian hard red winter wheat flour

The nature of variation in water absorption capacity in Canadian hard red winter (HRW) wheat genotypes was studied. Wheat and flour were evaluated for a range of physical and chemical properties including hardness indices, protein content, total and water-extractable arabinoxylan (WEAX) contents and flour particle size by laser diffraction. Absorption, as measured by farinograph (FA) ranged from 54 to 66%. The most highly correlated conventional parameters to FA were protein and WEAX contents, particle size index and starch damage, with correlations ranging from r = 0.37 to 0.56 in absolute values. The volume fractions of large and small flour particles had the highest correlations to FA (r∼0.67). Multivariate regression analysis produced 3 or 4 variable models of FA prediction with R2 ranging from 0.64 to 0.95, depending on the sample population. Results indicated that FA is a complex quality parameter with low values attributable to one or more of low levels of wheat hardness, protein content or AX content, depending on genotype. Improving FA in HRW wheat consistent with hard spring wheat appears to be feasible by increasing concentration of deficient parameters by breeding, especially WEAX which has high heritability and ample variation in the HRW wheat germplasm that was studied.

Microwave absorption capacity of rice flour. Impact of the radiation on rice flour microstructure, thermal and viscometric properties

The microwave radiation thermal treatment of rice flour was studied and its impact on physical and structural characteristic in relation to the initial moisture content (IMC) (20% and 30%) was evaluated. To explain the fundamentals of observed changes the microwave radiation absorption capacity of flour as well as temperature and moisture change during the treatment were evaluated. The flour particle morphological structure as well as crystallinity/amorphous region ratio changed after the treatment. The flour thermal properties also altered revealing IMC significant impact on the gelatinization temperature, that raised up to 3 °C, and the amylopectin retrogradation extent that increased up to a 7% in the most intense microwave-treated flours with respect to the native flour. Lower peak, setback and breakdown viscosities - that decreased with respect to the native flour up to 42%, 34% and 86% respectively-and higher pasting temperatures -that increased up to 10 ºC- were also observed. An exceptional microwave irradiation efficiency resulting in rice flour physical changes in significantly shorter times, 4–8 min, than conventional heat-moisture treatment processes was concluded.

СВЯЗЬ МЕЖДУ АКТИВНОСТЬЮ ЛИПОКСИГЕНАЗЫ И ТЕКСТУРОЙ ЭНДОСПЕРМА ГЕКСАПЛОИДНОЙ ПШЕНИЦЫ

The aim of the work was to study a correlation relationship between Lipoxygenase activity in the seeds of Triticum aestivum l. wheat and their endosperm texture parameters, i.e. the specific surface area of the flour, flour particle size and wheat vitreousness. A comparison between several wheat breeds and two populations of wheat alien substitution lines has shown that Lipoxygenase activity is positively correlated with the specific surface value of flour particles and is negatively correlated with wheat particle size (P ≤ 0,01). Under unfavourable environment conditions, a change in the endosperm texture parameters, namely the resistance indices of the Diamant 2 (Novosibirskay 67) wheat breed, are found to be correlated with the resistance indices of Lipoxygenase activity (P ≤ 0,05; 0,01). The endosperm texture is known to be an important technological characteristic of hexaploid wheat, which determines its milling characteristics and end use. Hard wheat varieties are used for bread-making, while soft ones are suitable for confectionery production. For the first time, a negative correlation between Lipoxygenase activity and grain hardness has been found. Lipoxygenase present in wheat seeds is likely to be involved in the formation of the endosperm texture, promoting its softness.

Two-phase flow in channels with non-circular cross-section of pneumatic transport of powder material

The paper presents a numerical simulation of two-phase turbulent flow in straight horizontal channels of pneumatic transport with non-circular cross-section. For the granular flow simulation, we have chosen the flow of solid particles of quartz, flour, and ash in the flow of air, which is transporting fluid. During the modeling of the flow, the transported solid particles are reduced to spherical shapes. A correction of the stress model of turbulence is performed by taking into account the influences of the induction of secondary flows of the second order in the gas phase. The full Reynolds stress model was used for modeling the turbulence, and the complete model is used for the turbulent stresses and turbulent temperature fluxes. All numerical experiments were conducted for the same initial flow conditions and a single uniform grid was adopted for all numerical experiments. The flow is observed in a straight channel of a square cross-section and dimensions of sides of 200 mm and the length of 80 Dh. During the simulation, the fineness of the numerical grid was also tested, and the paper shows results of the numerical grid of the highest resolution beyond which the fineness does not influence the obtained results. The paper offers graphics of velocities of the solid particles transported by the transporting fluid (air) along the channel.

Antioxidant activity and storage regime of defatted grape seeds flour

In the present paper, we examined the antioxidant activity of a defatted grape seeds flour of different grape varieties locally grown in Bulgaria. The seeds are retrieved after alcoholic fermentation and the antioxidant activity of the flour was assessed by using four different methods, namely DPPH, ABTS, FRAP and CUPRAC. The results are presented in mM TE/g extract. The values are 586,08 (±41,55); 945,41 (±90,97); 553,39 (±45,57) and 667,73 (±64,30), respectively. The results are also showed in mM TE/g flour. The values are 58,67 (±4,16); 94,64 (±9,11); 55,40 (±4,56) and 66,85 (±6,44), respectively. During three-month storage of the flour in plastic bags (temperature 25 ºC and relative humidity 75%), no living cells of pathogenic organisms (Escherichia coli, Staphylococcus aureus and Salmonella spp.) or apparent molding were detected. The flour particle size has not changed either.

Antioxidant activity and storage regime of defatted grape seeds flour

In the present paper, we examined the antioxidant activity of a defatted grape seeds flour of different grape varieties locally grown in Bulgaria. The seeds are retrieved after alcoholic fermentation and the antioxidant activity of the flour was assessed by using four different methods, namely DPPH, ABTS, FRAP and CUPRAC. The results are presented in mM TE/g extract. The values are 586,08 (±41,55); 945,41 (±90,97); 553,39 (±45,57) and 667,73 (±64,30), respectively. The results are also showed in mM TE/g flour. The values are 58,67 (±4,16); 94,64 (±9,11); 55,40 (±4,56) and 66,85 (±6,44), respectively. During three-month storage of the flour in plastic bags (temperature 25 ºC and relative humidity 75%), no living cells of pathogenic organisms (Escherichia coli, Staphylococcus aureus and Salmonella spp.) or apparent molding were detected. The flour particle size has not changed either.

Properties of an industrial extruded HDPE-WPC: The effect of the size distribution of wood flour particles

This work aims understanding the influence of the size distribution of wood flour particles on the physical and mechanical properties of an extruded wood plastic composite (WPC). A industrial-scaled process has been tested for both the wood flour production and the composite forming. Three size distributions of wood flour have been produced from the same batch of wood chips. The analyses of the particle size and form for the three wood flours were carried out by sieve column and by image analysis, revealing the limits of sieving in the case of particles with a high aspect ratio. The present study investigates the influence of the wood flour size distribution on the tensile and flexural behavior of WPC. The Charpy impact behavior of HDPE-WPC is also studied. In addition to the industrial process, the originality of this work lies in relating the microstructure to the mechanical performances of the extruded WPC; especially the orientation of the wood particles that differs according to the size distribution of the wood flour used. In general, mechanical performances of composites are improved by adding large particles. However, in the transverse direction to the extrusion, fine wood flour allows better performances.

Comparison of quality attributes of refined and whole wheat extruded pasta

This work aimed at developing pasta with different types of flour to evaluate how different raw materials and particle size affect pasta quality. Triticum aestivum flour was obtained from two cultivars: Klein Guerrero and Baguette Premium 11. Grains were milled into white flour, whole-grain flour A (obtained by a cyclonic mill) and whole-grain flour B (obtained by a blade mill) to make white flour (FP), whole-grain A (WFAP) and whole-grain B (WFBP) extruded pasta. Particle size distribution and flour composition were determined in all flour samples, as were pasta cooking and nutritional properties. All types of flour showed different particle size distribution depending on composition and milling method. Both whole-grain flour pasta showed shorter optimal cooking time than FP samples due to disruptions in the gluten matrix by bran-germ particles. Cooked WFAP and WFBP samples were harder than FP samples. The highest antioxidant properties were obtained for whole-grain pasta although flour particle size did not influence protein and antioxidant contents. Even though whole-grain pasta did not show the same technological quality as that in FP, they offered a better nutritional profile due to higher protein and antioxidant levels and other healthy compounds, like fiber, found in the whole grain.

Red–Green–Blue (RGB) colour system approach to study the segregation and percolation in a mixture of white wheat flour and bleached wheat bran

SummaryIn this work, we applied a nonintrusive measurement method based on the Red–Green–Blue (RGB) image analysis system to study the segregation and percolation in a mixture of white wheat flour and bleached wheat bran. This method intended to quantify the presence of one or several colours in the surface of mixed ingredients. The mixing of flour particles with bleached and unbleached wheat bran was studied using a 90 mm closed rotating cube. This system forced the particles to roll relative to each other so as to favourite the segregation by percolation in order to hide one colour by another. The obtained results showed a possibility of obtaining homogeneous colour when the wheat flour was mixed with the bleached wheat bran at a volume ratio of 20/5%–10%. By increasing to ratio up to 20/15% (flour/bran), the RGB system showed a presence of two colours in the surface of the mixture. Moreover, the RGB method confirmed the presence of two heterogeneous colours when the wheat flour was mixed with the unbleached wheat bran whatever the ratio (20/5%, 10% and 15%).

Physical and organoleptic characteristics of non-sour ‘kokoro’ (a Nigerian maize-based snack) as influenced by flour particle size differential

The influence of particle size grading of maize (Zea mays L.) flour on the quality attributes of non-sour kokoro (a Nigerian maize-based snack) was investigated. White maize grains (DMR-ESR-W) was used for the study and the flour obtained from them was subsequently categorized into 297–420, 420–500, 500–595 and < 595 μm (whole flour mixture) respectively. Non-sour kokoro was produced from each flour category followed by subsequent analyses. The results showed that the parameters which increased in values with decrease in flour particle size (500–595 to 297–420 μm) were peak viscosity (89–128 RVU), breakdown viscosity (30–47 RVU), final viscosity (138–164 RVU), setback viscosity (84–99 RVU), lightness index (43–55), browning index (62.8–78) and force-at-peak (42–57 N). Those that decreased in values with decrease in flour particle size were peak time (7.2–5.3 min) and oiliness index (86-39 cm2). The non-sour kokoro from 500 to 595 μm flour category was rated the highest in terms of colour, aroma, taste, texture and overall acceptability. The use of 500–595 μm flour category for the production of non-sour kokoro is therefore recommended.

The Effect of Navy Bean Flour Particle Size on Carbohydrate Digestion Rate Measured in Vitro

The consumption of navy beans (Phaseolus vulgaris L.) is associated with reduced cardiometabolic risk factors such as improved blood glucose control. Navy bean flours retain the nutritional benefits of navy beans, which are high in protein and fiber and low in fat and sugar. However, the particle size of navy bean flours can vary depending on the milling technology used. The purpose of this study was to investigate the carbohydrate digestion rate of navy bean flours with various particle sizes. Five samples each of raw and baked flours with the following volume-weighted mean particle sizes were studied by in vitro digestion using the Englyst method: coarse (1,101.6 μm), regular (630.7 μm), fine (301.7 μm), very fine (144 μm), and superfine (26.8 μm). An increase in the particle size of dry-milled navy bean flours was associated with a reduced in vitro carbohydrate digestion rate that was partially retained after baking and could be explained by the higher resistant starch and insoluble nonstarch polysacch...

Creation and Characterization of a Double Null Puroindoline Genotype in Spring Wheat

Wheat (Triticum aestivum L.) grain hardness is controlled by the Ha locus, which is composed of two closely linked genes, Puroindoline a (Pina) and Puroindoline b (Pinb). Hard grain results from mutations in either of the Pin genes. Previous results have shown that the Pina‐D1b (Pina null) allele has harder grain than other naturally occurring Pin alleles. Our goal was to create, identify, and characterize a double null Pin genotype by identifying a Pinb null mutation in a variety carrying the Pina‐D1l null allele. Seeds of Fortuna, which has a premature stop codon in Pina, were treated with ethyl methanesulfonate. Two premature stop codon mutations were identified in Pinb using direct sequencing. The double null Pin haplotype was characterized after backcrossing to the parent variety Fortuna to create Pina null populations segregating for the presence of Pinb. The double null group was 6 units harder than the single null with no difference in other kernel characteristics. The milling characteristics differed between the two classes; the double null class had less break flour with a greater fraction of large and a smaller fraction of small flour particles compared with the single null class. Neither water absorption nor loaf volume was impacted by the change in grain hardness; however, Na2CO3 tests indicated greater starch damage in the double nulls. The double null Pin genotype may find a niche in hard wheat products for which flours with larger particle size are desired.

Physiochemical Properties and Probiotic Survivability of Symbiotic Corn-Based Yogurt-Like Product.

Corn is a major grain produced in northern China. Corn-based functional food products are very limited. In this study, a symbiotic corn-based yogurt-like product was developed. Corn milk was prepared through grinding, extrusion and milling, and hydration processes. Corn extrudate was prepared under the optimized conditions of corn flour particle size <180 μm, moisture content of 15% and extrusion temperature at 130 °C. The corn milk was prepared from 8% corn extrudate suspension and then milled twice with 0.1% glyceryl monostearate and 0.1% sucrose ester as emulsifiers. The corn milk was mixed with sugar (5%), glucose (2%), soy protein isolate (0.75%), inulin (1%), polymerized whey protein (0.3%) and xanthan gum (0.09%) as thickening agents. The mixture was fermented at 35 °C for 6 h using a probiotic starter culture containing L. plantarum. Chemical composition (%) of the symbiotic corn-based yogurt-like product was: total solids (17.13 ± 0.31), protein (1.12 ± 0.03), fat (0.30 ± 0.05), carbohydrates (15.14 ± 0.19), and ash (0.16 ± 0.02), respectively. pH value of this symbiotic product decreased from 4.50 ± 0.03 to 3.88 ± 0.13 and the population of L. plantarum declined from 7.8 ± 0.09 to 7.1 ± 0.14 log CFU/mL during storage at 4 °C. SDS-PAGE analysis showed that there were no changes in protein profile during storage. Texture and consistency were also stable during the period of this study. It can be concluded that a set-type corn-based symbiotic yogurt-like product with good texture and stability was successfully developed that would be a good alternative to the dairy yogurt.

MALDI-TOF Mass Spectrometric Analysis of Zeins Extracted from Maize Seeds

Abstract We report the mass spectrometric analysis of zeins extracted from degreased maize flour with either an aqueous 70% ethanol solution or 60% acetonitrile containing 10 mM dithiothreitol. The analysis was performed on a MALDI-TOF mass spectrometer using α-cyano-4-hydroxycinnamic acid as matrix. The method allowed the detection of α-, β- and γ-zeins, but not δ-zeins and was used for the analysis of zein content in the maize inbred KWS 3381 and in commercial flour at different flour particles sizes: between 710 μm and 1.0 mm, between 250 μm and 355 μm and smaller than 100 μm.

The Effects of Micro- and Nano-Fillers’ Additions on the Dynamic Impact Response of Hybrid Composite Armors Made of HDPE Reinforced with Kevlar Short Fibers

ABSTRACTHybrid composite armors consisting of Kevlar short fibers reinforced high-density polyethylene were prepared and the effects of the addition of micro and nano-fillers on the dynamic impact response and the energy absorption under ballistic impact were investigated. Five groups of specimens were manufactured using compression molding of pellets containing mixtures of high-density polyethylene and the reinforcing materials. The first group consist of high-density polyethylene reinforced with 10 wt% Kevlar pulp (KN-1). The rest are hybrid composites created by the addition of 20 wt% of micro and nano-fillers. The natural micro-fillers used are particles of chonta palm wood (KN-2) and potato flour (KN-3). The synthetic nanofillers are colloidal silica (KN-4) and gamma alumina (KN-5). Microstructure (scanning electronic microscope) and compositional (energy-dispersive spectroscopy) analysis of the hybrid composites were carried out to evaluate matrix-reinforcements-interface. The fabricated composites plates were subjected to high velocity impact using split Hopkinson pressure bar system and ballistic impact, according to NIJ standard–0101.06 for ballistic resistance. Significant stiffness improvements of up to 43.5% were achieved as a result of the addition of synthetic nano-particles to Kevlar fiber reinforced high-density polyethylene. X-ray diffractometer analysis revealed that the crystalline structure of the Kevlar reinforced high-density polyethylene is unaffected by addition of the nano-particles as fillers. However the intensity of the crystalline peaks decreased depending on the type of the added fillers. The results of dynamic impact test using split Hopkinson pressure bar revealed improved impact resistance by addition of synthetic nanofillers (silica and alumina). The results of the ballistic impact test showed the gamma alumina nano-particles (KN-5) exhibited the highest energy absorption capability. The results of these investigations indicate that hybridization Kevlar short fibers reinforced high-density polyethylene by micro and nano-fillers addition enhances the stiffness, impact resistance and ballistic energy absorption capability of the composites.

Cashew tree wood flour activated with cashew nut shell liquid for the production of functionalized composites

This work is aimed at the one-step chemical modification of the surface of cashew wood flour particles using the technical grade cashew nut shell liquid (CNSL). The goal is to develop an alternative way to introduce chemically active sites on the surface of the particles, which allows the addition of new functionalities to such particles. The influence of time and temperature and catalyst on the substitution of lignocellulosic hydroxyls with cardanol/cardol urethane derivatives was evaluated by thermogravimetric analysis, scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), and contact angle measurements. The mechanical behavior of the modified particles in polypropylene composites was also evaluated by mechanical testing and dynamic mechanical thermal analysis. The FTIR, thermogravimetry, and contact angle results indicated changes on the particle surface, and the mechanical and thermomechanical behavior of the mercerized and modified particles in the composites was found to be similar. These results point that the CNSL approach is a viable way to chemically modify cashew wood flour particle surfaces, while maintaining their properties.