Dry Fraction Research Articles

Two steps of dry fractionation: Comparison and combination of air classification and electrostatic separation for protein enrichment from defatted rapeseed press cake

Two steps of dry fractionation: Comparison and combination of air classification and electrostatic separation for protein enrichment from defatted rapeseed press cake

Dry fractionation for endosperm recovery from a barley malt waste stream

Cereal processing industry removes the fibrous tissues from kernels via abrasive milling, but this tends to remove part of the valuable endosperm components as well. Therefore, endosperm recovery from such abraded barley malt material (53% endosperm and 47% husk) was evaluated for three dry separation technologies. Electrostatic separation recovered 25% of the endosperm at 85% purity and this recovery increased to 39% in a second run, which indicated potential to further improve the setup. Increasingly finer sieves removed up to 40% of the husk with little endosperm loss, but further husk removal up to 95% by the finest sieve reduced the endosperm yield to 54% due to decreasing differences in smallest diameter between the endosperm and husk particles. Air classification outperformed sieving by yielding 71% of the endosperm while removing 95% of the husk, and further, less selective air classification steps could yield up to 94% of the endosperm while still removing 59% of the husk. Moreover, such additional air classification steps currently recovered residual endosperm particles more selectively than electrostatic separation after an initial air classification. Overall, air classification after abrasive milling increased the removal of insoluble matter from malted barley kernels. The loss of soluble endosperm components remained similar to the loss as observed in a single abrasive milling step.

Influence of extraction method on inherent properties and techno‐functional behavior of quinoa protein ingredients

AbstractThis study investigated the structural modification and functional properties of quinoa protein ingredients using dry and wet fractionation techniques. Alkali extraction at pH 9.0 produced a quinoa protein isolate (QPI) with 76.2% wt/wt protein (dry basis) and a concentrate (QPC) with 55.9% protein. However, the protein separation efficiencies (PSE) were 32.1% and 58.5%, respectively. In contrast, dry fractionation produced a quinoa protein rich fraction (QPRF) containing 24.7% wt/wt protein, but higher PSE at 69.9%. Despite varying final protein concentrations, SDS‐PAGE showed similar relative abundance of 11S, 7S, and 2S proteins among the ingredients and quinoa whole meal. Mass spectrometry revealed different levels of oxidative modifications to proteins, with QPI showing more pronounced oxidation. In starch pasting experiments, QPRF exhibited significantly higher viscosity than QPI and QPC, attributed to low starch content and the formation of protein–starch and protein–lipid complexes in QPI and QPC. Solubility over pH 2.0–9.0 followed a U‐shaped trend for all ingredients, with QPC showing lower solubility at pH >7.0. Furthermore, foaming capacity and stability of foams converged at high ingredients concentration (3% wt/vol), while increasing protein refinement gave high foam stability at lower concentration (0.5–1% wt/vol). Similarly, emulsion activity index was favored at high purity (QPI), while emulsion stability was promoted at low protein purity (QPRF). This study demonstrated that dry fractionation enabled the retention of techno‐functional properties of the protein while enhancing quinoa bioresource recovery.

A new paradigm for the role of disturbance waves on film dryout and wall heat transfer in annular two-phase flow

The entire liquid-film dryout process in vertical annular two-phase boiling flow is characterized experimentally, from inception to completion, in a newly defined flow regime between annular two-phase flow and mist flow, called ‘intermittent dryout’. Experiments are conducted using saturated R245fa flowing vertically through a heated transparent channel. Liquid-film thickness measurements are taken during dryout events. The state (wet or dry) of the heated surface is determined using a laser reflectance measurement, and the signal is used to calculate the time-averaged dry fraction, fdry. The local heat transfer coefficient (HTC) is characterized as a function of fdry. For all the investigated mass fluxes, optimum boiling conditions (OBC), corresponding to the heat flux that results in maximum HTC, consistently occur when the time-averaged dry fraction is fdry≈0.05. Subsequently, the critical boiling transition (CBT), corresponding to the heat flux that results in a significantly lower HTC, can occur for dry fractions of fdry>0.1. Further insight into the liquid film behavior within the intermittent dryout regime is obtained by combining analyses of high-speed videos, time-resolved liquid-film thickness signals, and statistics about the duration of and time between dryout events. In general, the dryout mechanism is dominated by disturbance waves.Mechanistic model frameworks are presented for the prediction of two-phase HTC and heat flux associated with dryout. The model inputs are local flow quantities (pressure, mass flux, vapor quality, and liquid-film thickness) and output a prediction for local heat transfer coefficient. The model framework accurately predicts the local two-phase HTC for a range of mass flux and vapor quality in the annular flow regime. The model framework captures the observed initial increase in the local HTC and subsequent decrease that is associated with liquid-film dryout. The mechanistic approach provides predictions for time-averaged HTC and OBC heat flux that both agree well with experimentally measured values.

Dry-fractionated protein concentrate as egg replacer in sponge cake: how the rheological properties of the batters affect the physical and structural quality of the products.

Egg replacement is a notable food trend for academics and industry. Dry-fractionated protein concentrates (DFp) are minimally processed and sustainable ingredients. DFp from chickpea, red lentil and mung bean, prepared as aqueous dispersions at 20-40% (w/w), were used to replace egg in sponge cakes. To understand the effect of DFp on the physicochemical features of sponge cakes, the batter rheological properties (i.e., flow behavior, frequency-dependent and temperature-dependent behaviors) were investigated. Frequency sweep revealed a higher storage modulus (G') than loss modulus (G″), indicating predominantly elastic-like behavior, dependent on the frequency. Increasing DFp content, especially at 40%, resulted in firmer batters, indicated by elevated apparent viscosity. During temperature sweep, G' increased starting from 80 °C in all DFp-based batters, indicating protein and starch conformational changes. Higher DFp content better simulated the egg behavior, affecting specific volume and thickness variation after baking but resulting in harder cakes. Crumb structure was similar to the control, highlighting that DFp can emulate the egg behavior in cake preparation. Protein content in cakes containing 30% DFp was similar to the control. However, the addition of DFp caused an increase in phytic acid. Sensory analysis of sponge cakes revealed differences in crust color, sweetness and legume flavor, with minimal effect on astringency. Chickpea and lentil DFp are suggested as preferred alternatives because of their to milder sensory impact. Overall, eggs in cake formulation can be substituted by plant-based protein produced by dry fractionation. However, further research is essential to evaluate the nutritional characteristics. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Dry fractionation process operations in the production of protein concentrates: A review.

The market for plant proteins is expanding rapidly as the negative impacts of animal agriculture on the environment and resources become more evident. Plant proteins offer competitive advantages in production costs, energy requirements, and sustainability. Conventional plant-protein extraction is water and chemical-intensive, posing environmental concerns. Dry fractionation is an energy-efficient and environmentally friendly process for protein separation, preserving protein's native functionality. Cereals and pulses are excellent sources of plant proteins as they are widely grown worldwide. This paper provides a comprehensive review of the dry fractionation process utilized for different seeds to obtain protein-rich fractions with high purity and functionality. Pretreatments, such as dehulling and defatting, are known to enhance the protein separation efficiency. Factors, such as milling speed, mill classifier speed, feed rate, seed type, and hardness, were crucial for obtaining parent flour of desired particle size distribution during milling. The air classification or electrostatic separation settings are crucial in determining the quality of the separated protein. The cut point in air classification is targeted based on the starch granule size of the seed material. Optimization of these operations, applied to different pulses and seeds, led to higher yields of proteins with higher purity. Dual techniques, such as air classification and electrostatic separation, enhance protein purity. The yield of the protein concentrates can be increased by recycling the coarse fractions. Further research is necessary to improve the quality, purity, and yield of protein concentrates to enable more efficient use of plant proteins to meet global protein demands.

Development of dual stage solvent fractionation as an approach to concentrate carotenoids from crude palm oil with high recovery: The potential use of molecular simulation as a pre‐screening tool

AbstractCrude palm oil (CPO) is highly abundant in carotenoids. Previous findings found that dry fractionation can concentrate carotenoids from CPO but resulted in a significant loss of carotenoids. Therefore, the present study aimed to utilize solvent fractionation, which offers a better separation efficiency, to concentrate carotenoids from CPO with improved recovery. Computational study revealed a high binding affinity of phytonutrient towards unsaturated triacylglycerols (TAGs) species in olein fraction due to similar polarity. This prediction was further verified with evidence showing strong, positive correlation between the iodine value and carotenoids concentrations of fractionated oil. The difference in binding affinity of saturated and unsaturated TAG towards different solvents can be used as a guide for screening and selection of solvent suitable for recovery of phytonutrient during solvent fractionation. Subsequently, a lab‐scale single‐ stage fractionation study disclosed that crystallization temperature of 15°C, oil to acetone ratio of 1:5 (w/v) for 4 h under agitation at 100 rpm produced olein with the highest carotenoid concentration (637 ppm) and recovery (94%). Subsequent double‐stage fractionation successfully concentrated the carotenoids up to 125% with a recovery of >93%. Conclusively, solvent fractionation provides an effective way to concentrate valuable carotenoids from CPO while minimizing the lost.

Dry Fractionation and Gluten-Free Sourdough Bread Baking from Quinoa and Sorghum.

The roller milling of sorghum and quinoa seeds into flour fractions (coarse, middle, and fine) was investigated, chemically analysed, and applied in the baking of gluten-free sourdough bread. The gap settings were adjusted to 0, 5, 8, and 10 for quinoa, and 3, 5, and 7 for sorghum. The fine fractions reached values of up to about 41% (gap 8) for quinoa and around 20% for sorghum (gap 5). SEM pictographs illustrated the clear separation of each fraction with the chemical analysis showing high contents of protein, TDF (total dietary fibre), and IDF (insoluble dietary fibre) in the coarse fraction. Up to 77% starch content was obtained in the fine fraction with significant amounts of SDF (soluble dietary fibre), which has good health benefits. Increasing the dough moisture up to 90% helped in decreasing the bread crumb firmness, while low Avrami parameters and RVA pasting behaviour indicated a slow bread-staling rate for both sourdough breads.

Decoding the role of triacylglycerol composition in the milk fat crystallisation behaviour: A study using buffalo milk fat fractions

The role of triacylglycerols (TAGs) composition in milk fat crystallisation is evaluated from a new perspective by correlating the crystal structures and their predicted TAG contributors. Four different TAG groups, defined by their fatty acid (FA) chain length and saturation are proposed to explain the crystallisation behaviour of different milk fat samples, namely TAGs containing (i) fully saturated long chain FAs, (ii) single unsaturated long-chain FA and (iii) multi unsaturated long-chain FAs, as well as (iv) short-chain FAs. Samples containing different TAGs proportions were obtained from two-step dry fractionation of buffalo milk fat. Liquid chromatography and mass spectrometry (LCMS) was employed to determine the TAGs composition. The crystallisation characteristics were evaluated using small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC) and polarised light microscopy. The results confirm that fully saturated long chain TAGs are responsible for the formation of high melting point 2L-crystals (d-spacing: 44.1–49.7 Å), whilst the low melting point 3L-crystals (64.4–72.8 Å) are mainly contributed by long chain TAGs containing unsaturated fatty acids. Further, the crystallisation inhibiting effect of asymmetrical TAGs, containing short chain fatty acid (C4-6) is evident. As a final point, effects of the four TAG groups, each given with a specific composition, were examined closely also with respect to their influence on the nucleation and polymorphic transformation kinetics of milk fat crystals.

How fractionation procedure of mung bean protein affects transglutaminase crosslinking

Transglutaminase is often used to improve functional properties of plant proteins. Here, we report on the effects of the fractionation procedure on transglutaminase susceptibility of mung bean proteins at three length scales: molecular, colloidal and bulk. Dispersions of 4 wt% mung bean protein fractions were treated with transglutaminase. The four fractions were obtained through (1) dry fractionation (fine fraction); (2) dry fractionation with additional heating; (3) lab-scale wet fractionation; and (4) a commercial protein isolate. Analysis of rheological properties (at 9.5 wt% dry matter) revealed that transglutaminase crosslinking formed tougher materials when using the fine fraction, the heated fine fraction, and the wet fractionated isolate, while the rheological properties of the protein isolate were hardly changed. Proteins in all fractions were crosslinked by transglutaminase at molecular scale, as confirmed by an increase in large molecular weight bands in gel electrophoresis, but the extent of crosslinking depended on the fraction used. The molecular changes also resulted in altered physical chemical properties for some fractions, as revealed by protein dispersibility, confocal laser scanning microscopy, and particle size distribution. At the colloidal scale, transglutaminase crosslinking led to an increased particle size in the fine fraction and heated fine fraction, while particle sizes of the wet fractionated isolate and commercial protein isolate were mostly unaffected. The differences between the fractions were explained by three mechanistic crosslinking routes. To conclude, protein fractionation procedure greatly affected susceptibility to transglutaminase.

Pharmacokinetic assessment and phytochemical triterpene control from Cecropia angustifolia using plant biotechnology.

Cecropia angustifolia Trécul. is a native Andean plant containing high levels of pentacyclic triterpenes (PTs), including several isobaric molecules that serve as chemical markers. Preclinical studies suggest that PTs positively modulate metabolic and vascular diseases. However, their low oral absorption reduces their bioactive effects. The objective of this study was (1) to improve the absorption of PTs from C. angustifolia and (2) to establish a platform to produce biomass or botanical reference material using a strategy for their accumulation. MALDI-TOF and UPLC-MS were used to characterize and quantify PTs in different matrices. An in vitro platform for PT production was established. Chemical profiles of triterpenes were also evaluated from wild and in vitro herbal material using TLC coupled with mass spectrometry. To overcome the low absorption of PTs, a premier raw material was used, which increased their bioavailability to 9.2%. Active ingredients in herbal material can vary, and there is an urgent need for standardized extracts using pharmacokinetics as an effective tool to reveal the dynamics of active ingredients in vivo. A temporary immersion system was produced as a promising platform with a total PT accumulation exceeding 50% of the content in the dry fraction, indicating it is a feasible mechanism to produce biomass or botanical reference material. Plant tissue culture is a promising eco-friendly technology for phytochemical production and a modern strategy to protect biodiversity in natural assets. Alternative and modern, yet environmentally friendly production methods are needed to meet the large demand for herbal products.

Physical, interfacial and foaming properties of different mung bean protein fractions

Mung bean is an upcoming source of plant proteins with good foaming properties. The relation between its foaming properties and interfacial properties has not received much attention and was addressed in this work. To this end, five different mung bean protein fractions were produced. First, a protein-rich flour was obtained using dry fractionation, which was further processed into a protein mixture using mild wet fractionation to remove starch granules and other insoluble components. The protein mixture was further treated by isoelectric point precipitation to obtain a globulin- and albumin-rich fraction. Finally, we used the protein nativity of the dry fractionated flour to create protein coacervate droplets via liquid-liquid phase separation of the proteins at slightly acidic pH. The protein-rich coacervate droplets were heated and cross-linked into gelled particles, or “protein colloids”. The interfacial and foam-stabilising properties of the flour and protein mixture were dominated by the globulins, producing a foam with a poor stability. Also, non-proteinaceous components, such as starch granules, phenols and phospholipids, seemed to reduce foam stability. Albumins formed substantially stiffer interfaces, leading to foams with a high stability. The highest foam stability was observed for the protein colloids, which we attribute to the formation of stiff interfacial layers and probably also pinning of the lamellae in the foams by the protein colloids. In summary, mung bean albumins were found to possess substantially better foaming properties than the globulins, but especially mung bean protein colloids are a promising candidate for a plant-based foam ingredient.

Fatty acid, triglyceride, and kinetic properties of milk fat fractions made by the combination of dry fractionation and short-path molecular distillation

In this study, we aimed to detect the physicochemical properties of distilled products (residue and distillate) obtained from anhydrous milk fat (AMF) and its dry fractionation products (liquid and solid fractions at 25°C (25 L and 25 S)). The results showed that the saturated fatty acids and low- and medium-molecular-weight triglycerides were easily accumulated in the distillate, and the percentage of unsaturated fatty acid and high-molecular-weight triglycerides in the residue were higher, and these components in 25 S and 25 L were influenced more significantly than those in the AMF. In addition, the distillate had larger melting ranges in comparison with the distilled substrate, while the melting ranges of residue was smaller. The triglycerides were presented as the mixture crystal forms (α, β', and β crystal) in 25 S, AMF, and their distilling products, and it was transformed gradually to a single form as the increasing of distilling temperature. Moreover, the accumulated pattern of triglycerides was double chain length in 25 S, AMF, and their distilling products. These results provide a new approach to obtain the MF fractions with different properties, and the findings of this study enrich the theoretical basis of MF separation in practical production.

Towards dry fractionation of soybean meal into protein and dietary fiber concentrates

Tribo-electrostatic separation of hexane-defatted soybean flour was studied to produce protein- and fiber-rich fractions. The separation was carried out under laminar and turbulent airflow rates and plate voltages ranging from ±1 to ±6.5 kV. The combination of laminar airflow rate and high plate voltage resulted in the highest yield of protein and fiber particles with modest enrichment levels. Accordingly, the soybean flour was enriched in protein from 55.3 to 58.4% and fiber from 15.4 to 19.6%, accounting for 44.4 and 16.8% protein and fiber separation efficiencies, respectively. The distribution of protein and fiber along the negatively charged electrode showed no significant difference in terms of enrichment level. Still, more protein and fiber particles accumulated at the bottom of the electrode, according to the yield results. At 7 LPM and ±6.5 kV, a direct relationship was found between protein content and the average particle size of the fractions. In contrast, a reverse relationship was found for the fiber content. • Soybean meal flour was fractionated via dry tribo-electrostatic separation. • The impact of voltage and flow rate on protein and fiber enrichment was investigated. • Laminar airflow and high voltage resulted in modest protein and fiber enrichments. • Protein and particle size of the fractions were directly correlated at laminar flow. • The protein and fiber were uniformly enriched along the negative electrode.

Mild Fractionation for More Sustainable Food Ingredients.

With the rising problems of food shortages, energy costs, and raw materials, the food industry must reduce its environmental impact. We present an overview of more resource-efficient processes to produce food ingredients, describing their environmental impact and the functional properties obtained. Extensive wet processing yields high purities but also has the highest environmental impact, mainly due to heating for protein precipitation and dehydration. Milder wet alternatives exclude, for example, low pH-driven separation and are based on salt precipitation or water only. Drying steps are omitted during dry fractionation using air classification or electrostatic separation. Benefits of milder methods are enhanced functional properties. Therefore, fractionation and formulation should be focused on the desired functionality instead of purity. Environmental impact is also strongly reduced by milder refining. Antinutritional factors and off-flavors remain challenges in more mildly produced ingredients. The benefits of less refining motivate the increasing trend toward mildly refined ingredients.

Lentil and Mungbean protein isolates: Processing, functional properties, and potential food applications

Among the wide range of plant-based protein sources, pulse proteins stand out for their nutritional values and functional properties, together with sustainability. The global attention on soy and pea proteins, however, has overlooked other pulses. This review has explored underutilized and under-researched pulses, lentils and mungbean, by considering their comparable protein contents but different protein composition to that of soy and pea proteins. The traditional subsistence farming of lentils and mungbean has evolved with their emergence in the global agriculture sector. Research on lentil and mungbean protein extraction, however, has not been as extensive as for soy and pea. The novel dry fractionation methods benefiting protein native structure are in the early stage of optimizing protein yield. The milder wet extraction techniques-ultrafiltration or salt extraction-dilutive precipitations-have been investigated to a lesser extent. The harsh conventional wet extraction, i.e. alkaline extraction-isoelectric precipitation, is widely employed for lentils and mungbean. Apart from extraction method, drying process, pH condition, and genetic makeup of the plants directly influence protein functional properties. Protein functional properties, including gelation, emulsification, water holding (WHC) and oil absorption capacities (OAC), and foaming of lentils and mungbean, are discussed to understand their potentiality in the development of meat analogs. Lentil protein exhibited comparable gelling, emulsifying, and superior foaming properties to pea and soy protein. Meanwhile, the gelling, WHC and OAC of mungbean proteins are comparable to soy. This review highlights the promising application of lentil and mungbean proteins as sustainable plant-based protein sources for human food applications.

Antioxidant property of palm oil blended ghee and its fractions

Ghee is a high-priced product that costs three to six times than the edible vegetable oil. Dry fractionation is one of the cost-effective methods of modifying the physical properties of milk fat. Natural antioxidant present in palm oil is believed to enhance the oxidative stability of ghee. Therefore, in the current study, ghee was intentionally blended with palm oil at levels of 0,5, 10, and 20%. Then the ghee was fractionated to separate liquid and solid portions by dry fractionation technique. The antioxidant activity accessed by the 2, 2-diphenyl-1-picrylhydrazyl (DPPH)method shows that as the palm oil (especially tocotrienols and tocopherols) level increased the antioxidant activity in the prepared samples. This could be due to carotenoids and vitamins E which act synergistically as powerful natural antioxidants which also contribute better towards stability against auto oxidation(peroxide value). The liquid fraction (L20 with palm oil 20%) has a high level of antioxidant activity. Fractionated ghee, especially the liquid fraction showed higher antioxidant activity as compared to ghee could be due to its higher vitamin E activity. The peroxide value and free fatty acid content of ghee were determined during storage at 30°C and 60°C for 90 days. Liquid fractions showed more peroxide value and FFA as the storage day increased than solid fractions, which contained more peroxide value and FFA than control samples.

Optimization of Grinding Process of Sunflower Meal for Obtaining Protein-Enriched Fractions

In this study, dry fractionation process was proposed in order to obtain protein-enriched sunflower meal fractions. The process includes two-stage grinding using a hammer mill and a roll mill, and fractionation of sunflower meal by sieving. Central composite design (CCD) with four variables on three levels within response surface methodology was applied in order to estimate the influence of grinding parameters (sieve openings diameter of the hammer mill: 2, 4, and 6 mm, roll gap: 0.15, 0.2, and 0.25 mm, feed rate: 0.1, 0.175, and 0.25 kg/cm min, and roll speed: 400, 500, and 600 rpm) on responses (protein content, fraction yield and grinding energy consumption). Sieve openings diameter expressed the highest impact on fraction yield while roll gap expressed the most dominant influence on protein content in the fraction and grinding energy consumption. The highest protein content obtained was 48.06%(dm) with fraction yield of 77.22%. A multi-response optimization procedure was performed and optimal values were: sieve openings diameter of 2 mm, roll gap of 0.25 mm, feed rate of 0.2 kg/cm min, and roll speed of 400 rpm, while predicted values for a desired range of responses were: protein content 45.5%(dm), fraction yield 77.89%, and grinding energy consumption 8.31 Wh/kg.

Biocrust-linked changes in soil aggregate stability along a climatic gradient in the Chilean Coastal Range

Abstract. Biological soil crusts (biocrusts) composed of cyanobacteria, bacteria, algae, fungi, lichens, and bryophytes stabilize the soil surface. This effect has mainly been studied in arid climates, where biocrusts constitute the main biological agent to stabilize and connect soil aggregates. Besides, biocrusts are an integral part of the soil surface under Mediterranean and humid climate conditions, mainly covering open spaces in forests and on denuded lands. They often develop after vegetation disturbances, when their ability to compete with vascular plants increases, acting as pioneer communities and affecting the stability of soil aggregates. To better understand how biocrusts mediate changes in soil aggregate stability under different climate conditions, we analyzed soil aggregate samples collected under biocrust communities from four national parks in Chile along a large climatic gradient ranging from (north to south) arid (Pan de Azúcar, PA), semi-arid (Santa Gracia, SG), Mediterranean (La Campana, LC) to humid (Nahuelbuta, NA). Biocrust communities showed a stabilizing effect on the soil aggregates in dry fractions for the three northern sites and the wet aggregates for the southernmost site. Here, permanent vascular plants and higher contents of organic carbon and nitrogen in the soil control aggregate stability more than biocrusts, which are in intense competition with higher plant communities. Moreover, we found an increase in stability for aggregate size classes < 2.0 and 9.5–30.0 mm. The geometric mean diameter of the soil aggregates showed a clear effect due to the climatic gradient, indicating that the aggregate stability presents a log-normal instead of a normal distribution, with a trend of low change between aggregate size fractions. Based on our results, we assume that biocrusts affect the soil structure in all climates. Their role in aggregate stability is masked under humid conditions by higher vegetation and organic matter contents in the topsoil.

Effect of oil content on pin-milling of soybean

Milling is a critical step to prepare plant-based food ingredients by dry fractionation. It should provide a dispersible flour of finely milled particles composed of different cellular substructures. Especially, for raw materials with higher oil content such as soybean, this is challenging. We present an investigation on the effect of oil content on milling yield, particle size, energy use and flour dispersibility upon pin-milling of soybean. Soybean (20 g oil/100 g dry solids) and mechanically de-oiled soybeans (9–17 g oil/100 g dry solids) were subjected to pin-milling experiments. Increasing soybean oil content limited milling to smaller particles and lowered the overall milling yield. Particle size reduction can be described with an adapted Bond's model with oil content as an input parameter. The produced soy flours were well dispersible. • Particle size reduction was described with an oil-independent Bond's constant. • All pin-milled soy flours had a low degree of de-agglomeration. • Dispersion of fine particles showed an optimum for soy with high oil content. • All milled soy flours were dispersible and may be used for dry fractionation.