Bran Particles Research Articles

Bran-Enriched Milled Durum Wheat Fractions Obtained Using Innovative Micronization and Air-Classification Pilot Plants

Dietary guidelines recommend the consumption of unprocessed, or minimally processed, wheat foods because they are richer in health-promoting components (i.e., minerals, vitamins, lignans, phytoestrogens, and phenolic compounds) compared to traditionally refined products. The design and implementation of technological solutions applied to the milling process are becoming a key requirement to obtain less refined mill products characterized by healthier nutritional profiles. This study presents the development of an upgraded micronization plant and of a modified air-classification plant to produce several novel types of durum wheat milling fractions, each enriched in bran particles of different sizes (from 425 µm > Ø to Ø < 180 µm) and percentage ratios. A preliminary quality assessment of the milling fractions was carried out by measuring yield percentages and ash content, the latter being related to detect the presence of bran particles. A wide array of milling fractions with different original particle size compositions was provided through the study of the process. Results indicate the ability of the novel pilot plants to produce several types of less refined milling fractions of potential interest for manufacturing durum wheat end-products beneficial for human health.

High-intensity ultrasound treatment for prolongation of wheat bran oxidative stability

Wheat bran has a short shelf life, which could be prolonged by reducing the activity of enzymes in lipid degradation. In this study, high-intensity ultrasound treatment (400 W, 80% amplitude, 15 min), with or without cooling, was investigated for reducing the activity of lipase and peroxidase of wheat bran. Lipid stability parameters (free fatty acid content, peroxide value, anisidine value) of bran with coarse and reduced particle size (median 50th percentile diameter 503 and 177 μm, respectively) were followed under ambient or refrigerated storage conditions. Ultrasonic treatment without accompanying cooling inactivated 63% of lipase and 90% of peroxidase, but also decreased the antioxidant activity of bran by 13%. Compared with the untreated bran, the ultrasound-treated bran was darker, redder, and yellower. When ambiently stored, the critical anisidine value (10) of the unprocessed bran was exceeded after only 2 months, whereas the ultrasound-treated bran had an acceptable anisidine value for almost 12 months. Cooling during ultrasonication limits the ability to inactivate enzymes, and the reduction in bran particle size promotes its oxidative deterioration. The application of high-intensity ultrasound without cooling is beneficial for prolonging the oxidative stability of wheat bran compared to refrigerated storage.

Preliminary Investigations on the Use of a New Milling Technology for Obtaining Wholemeal Flours

Wholemeal flours from various cereals and pseudocereals are a valuable source of nutritionally important fiber components, especially beta-glucans and arabinoxylans, as well as bioactive substances accompanying dietary fiber. Most types of whole-wheat flours have unfavorable baking and sensory properties. The finest granulation of bran particles in the flour has a significant effect on reducing or eliminating these deficiencies. Special disintegration equipment is required to achieve fine granulation of the bran particles. In this study, we have tested a special type of impact mill (originally intended for grinding of plastics) to produce special finely ground wholemeal flours with lower starch damage and higher farinographic absorption. Moisture content in the studied flours was significantly lower (7.4–9.8%) than is common in standard flour (13–14%). According to the results of flour analyses obtained from several cereal sources, it seems that especially in rye and wheat, this technology is suitable for both achieving fine granulation of bran particles and in terms of not very substantial damage of starch granules.

Deformation index (GDI) in grain as a criterion for wheat gluten quality

The nutritional benefits of wheat bread largely depend on quality and content of the most valuable part of the grain, its protein complex, namely elastic, and quite extensible gluten. In recent years, there has been a tendency for deterioration of grain quality indicators, namely the indicator ‘gluten quality’ regulated by GOST. There are often the circumstances, when gluten acquires properties of increased viscosity and bran particles are firmly held by gluten proteins. In this case, it is practically impossible to extract it and it is characterized by the term ‘non-extractable’. At the same time, gluten extracted from flour (in the absence of bran) of the same grain sample corresponds to the 1-st and 2-nd classes of quality. Thus, in the first variant, the producers face losses as the grain of the 5th class is non-food, and in the other, we get good grain when gluten is extracted out of flour. The breeders of the research institutions face the similar dilemma when selecting breeding material according to gluten quality. Both different ways of extracting gluten often give opposite effect for the same genotype. The purpose of the current study was to assess the conformity degree of GDI, identified according to GOST according to such indicators as GDI in flour, sedimentation, rheological properties on a mixograph. In order to estimate if wheat is strong, valuable and weak, there is not enough only elastic ity, which is identified using the GDI device (gluten deformation index). The deformation index after extracting gluten is not always an objective result of its quality, therefore, there is a need in additional study, e.g. determination of the gluten deformation index (GDI) in flour, SDS sedimentation, rheological properties of the dough on a mixograph, which characterize gluten ‘strength’ (elasticity, strength, etc.). These methods will allow researchers to estimate the quality of breeding material more efficiently, and agricultural producers will have a comprehensive description of gluten quality of grown grain.

Preparation and characterization of a novel packing material for the gas-phase fluidized-bed bioreactor

Gas-phase fluidized-beds reactor (FBR) can overcome the shortages of bed clogging and performance decline in packed-bed reactors on VOCs treatment. Ideal FBR packing materials with minimum fluidized velocity and surface characteristics are required. In this study, an expanded polystyrene (EPS) with particle size 1.0–2.0 mm was selected as the skeleton among six types of EPS and two types of expanded polypropylene (EPP). They were then physically coated with a combination of potato dextrose medium, fine wheat bran particles, and inorganic glue. Different glue concentrations and amounts of medium were tested and the optimal values of 2 % and 0.22 g∙cm−2 were achieved. The wheat-coated EPS obtained hydrophilic functional groups on the surface, and its contact angle decreased from 93° to 37° after coating. By scanning electronic microscopy, more microorganisms were observed on the surface of the coated EPS than that of the uncoated EPS. A lab-scale fluidized bioreactor was built to treat gaseous ethanol. The minimum fluidized velocity of coated packing materials was 0.2 m∙s−1 under a relative humidity of 50 ± 10 %, reaching an average elimination capacity of 681 g m-3 h−1 during the 28-days operation, while the bioreactor packed with uncoated EPS reached only 18 g m−3 h−1.

Influence of Durum Wheat Bran Particle Size on Phytochemical Content and on Leavened Bread Baking Quality.

Wheat bran is a conventional by-product of the wheat milling industry mainly used for animal feed. It is a rich and inexpensive source of phytonutrients, so is in demand for fibre-rich food products but creates quality issues when incorporated into bread. The purpose of this study was to characterize the physicochemical properties and phytochemical composition of different size durum bran fractions and show how they impact bread quality. Durum wheat (Triticum durum Desf.) was milled to create a coarse bran fraction (CB), which was further ground into a finer fraction (FB) which was sieved using four screens with apertures 425, 315, 250, 180, and <180 µm to create a particle size range of 1497 to 115 µm. All fractions contained phytosterol with highest in the 180 and FB, while total phenolic acids and antioxidant capacity was highest in CB and 425. Use of the fractions in a leavened common wheat (T. aestivum L.) bread formula at 10% incorporation negatively impacted bread loaf volume, colour, and texture compared to standard loaves, with CB having the least impact. Results suggest that to combine the highest phytochemical content with minimal impact on bread quality, bran particle size should be considered, with CB being the best choice.

Influence of particle size reduction and high‐intensity ultrasound on polyphenol oxidase, phenolics, and technological properties of wheat bran

Wheat bran is a by-product rich in bioactive compounds, but possess a strong polyphenol oxidase (PPO) activity, which can act undesirably on product quality. This study aimed to optimize the particle size (500, 255, and 10 µm) of wheat bran and time and amplitude of high-intensity ultrasound (HIU) treatment on the PPO activity, total phenolics, antioxidant activity, and water swelling using response surface methodology. The PPO activity decreased depending on the particle size and HIU treatment time. Phenolic content, antioxidant activity, and swelling were dependent on bran particle size. Temperature rise, depending on the HIU time and amplitude, affected PPO, phenolics, and antioxidants. In optimized conditions (particle size 10 µm, HIU 15 min), 93% of bran PPO was inactivated while phenolic content increased for 11%. Wheat flour combined with micronized and ultrasonically treated bran (at 20% wt/wt) had improved gluten formation and pasting properties compared with flour containing native bran. Practical applications Consumers show a growing awareness of health benefits of whole wheat and high-fiber foods. Bran is a by-product of milling industry with a great potential as a functional food ingredient. However, the enzymatic browning of bran containing products that occur during processing worsens their sensory properties, nutritional value, and consumers’ acceptance. Currently, new technologies such as micronization and ultrasound treatment are getting more attention in cereal processing. This study showed that the combined micronization and high-intensity ultrasound treatment can successfully inactivate the polyphenol oxidase (up to 93%) from wheat bran, and thus, prevent the enzymatic browning. Also, treated bran can be successfully incorporated up to 20% to wheat flour with lesser disruption of the gluten formation and pasting properties when compared with the native bran. The findings of this study contribute to better future usages of wheat bran in food applications adding the sustainability of cereal chain.

On the Use of Biobased Waxes to Tune Thermal and Mechanical Properties of Polyhydroxyalkanoates-Bran Biocomposites.

In this work, processability and mechanical performances of bio-composites based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) containing 5, 10, and 15 wt % of bran fibers, untreated and treated with natural carnauba and bee waxes were evaluated. Wheat bran, the main byproduct of flour milling, was used as filler to reduce the final cost of the PHBV-based composites and, in the same time, to find a potential valorization to this agro-food by-product, widely available at low cost. The results showed that the wheat bran powder did not act as reinforcement, but as filler for PHBV, due to an unfavorable aspect ratio of the particles and poor adhesion with the polymeric matrix, with consequent moderate loss in mechanical properties (tensile strength and elongation at break). The surface treatment of the wheat bran particles with waxes, and in particular with beeswax, was found to improve the mechanical performance in terms of tensile properties and impact resistance of the composites, enhancing the adhesion between the PHBV-based polymeric matrix and the bran fibers, as confirmed by predictive analytic models and dynamic mechanical analysis results.

THE EFFECT OF DIFFERENT SIZED QUINOA BRAN FLOUR USAGE ON THE PHYSICAL, SENSORY AND TEXTURAL PROPERTIES OF BISCUITS

Kinoa, mükemmel besin değeri nedeniyle insan diyeti için oldukça önemlidir. Ancak, kinoanın teknolojik uygulamaları, glutensiz yapısı nedeniyle daha az ilgi görmüştür. Ayrıca kinoa yan ürünü olan kinoa kepeği esas olarak hayvan yemi olarak kullanılsa da insan sağlığı üzerinde olumlu etkisi olan potansiyel bir diyet lifi kaynağıdır. Bu çalışmada farklı boyutlarda kinoa kepek unu kullanımının bisküvilerin fiziksel, tekstürel ve duyusal özellikleri üzerine etkilerinin incelenmesi amaçlanmıştır. Bu amaçla, kinoa kepekleri değirmende 5 farklı boyutta öğütülmüş ve buğday unundan yapılmış bisküvilere %25 oranında eklenmiştir. Elde edilen sonuçlara göre kinoa kepek ununun boyutları küçüldükçe örneklerin kuru madde oranı artış göstermiştir. Yine kepek unu boyutlarının küçülmesi ile bisküvilerin dış parlaklık değerlerinde artış gözlenmiştir. Bisküvilerin tekstür ve duyusal özelliklerinde kinoa eklenmesi sonucunda azalış belirlenmiştir. Bu çalışma farklı boyutlardaki kinoa kepek unu ile zenginleştirilen bisküvilerin özelliklerinde meydana gelen değişimleri ortaya koymuştur.

Investigations of Micro-Milling Parameters in Woven Banana Fibre Reinforced Polymer Composite Filled with Rice Bran Particles

In modern day of manufacturing, micromachining plays a key function in machining of new developed harder materials, which is an alternate machining procedure for many processes in industrial scenario. The core objective of this current effort is to progress a micromachining setup and to examine effects of micromachining parameters, for which an open source small Arduino CNC machine was developed for performing the micro-milling operation on a natural fibre (banana) and rice bran particles reinforced polymer matrix composite material with fiber resin combination of 1:3. By using Taguchi method experiments combinations were formulated considering speed, feed and depth of cut and the outputs of MRR and surface roughness were investigated using TOPSIS methodology for identifying the optimal parametric conditions. Analysis of variance is employed for identifying the most significant parameter and a validation experiment was performed with the identified optimum conditions.

Impact of wheat bran particle size on the technological and phytochemical properties of durum wheat pasta

In this study 7 bran fractions were produced by grinding coarse durum wheat bran followed by sieving to achieve median particle size ranges between 115 and 1497 μm. These bran fractions were incorporated into pasta at 1, 5, 10 and 20% and the phytochemical and technological properties evaluated. Higher incorporation of bran, especially at 20%, reduced pasta quality, but a reduced impact was seen at the same degree of incorporation using finer bran. Bran increased antioxidants (by up to 65%), ferulic acid (up to 400%) and phytosterols (up to 130%) in pasta, parameters which were insensitive to bran particle size above 10% incorporation except for ferulic acid, which was higher in particles between 248 and 1497 μm. It is recommended to use finer fractions if bran is added to pasta at 20% and higher, since they provide a better quality pasta while still delivering enhancements in phytochemical content above regular semolina pasta.

Cereal bran protects vitamin A from degradation during simmering and storage.

Food supplementation with vitamin A is an efficient strategy to combat vitamin A deficiency. The stability of vitamin A during cooking and storage is, however, low. We here show that cereal bran protects retinyl palmitate (RP) during simmering and storage. Native wheat bran stabilized RP the most during simmering. About 75% RP was recovered after 120min of cooking, while all RP was lost after 80min in the absence of bran. Heat-treated rice bran protected RP the best during forced storage, with a 35% recovery after 8weeks. RP was degraded entirely in the absence of bran in less than one week. Results suggested that the physical entrapment of oil within the large wheat bran particles protects RP from the action of water and pro-oxidants during simmering. During storage, the high amount and diversity of lipid components present in rice bran are presumably responsible for its protective effect.

Maize Bran Particle Size Governs the Community Composition and Metabolic Output of Human Gut Microbiota in in vitro Fermentations.

Differences in the chemical and physical properties of dietary fibers are increasingly known to exert effects on their fermentation by gut microbiota. Here, we demonstrate that maize bran particle size fractions show metabolic output and microbial community differences similar to those we previously observed for wheat brans. As for wheat brans, maize bran particles varied in starch and protein content and in sugar composition with respect to size. We fermented maize bran particles varying in size in vitro with human fecal microbiota as inocula, measuring their metabolic fate [i.e., short-chain fatty acids (SCFAs)] and resulting community structure (via 16S rRNA gene amplicon sequencing). Metabolically, acetate, propionate and butyrate productions were size-dependent. 16S rRNA sequencing revealed that the size-dependent SCFA production was linked to divergent microbial community structures, which exerted effects at fine taxonomic resolution (the genus and species level). These results further suggest that the physical properties of bran particles, such as size, are important variables governing microbial community compositional and metabolic responses.

Triboelectric separation of wheat bran tissues: Influence of tribo‐material, water content, and particle size

AbstractThe separation behaviors of wheat bran tissues with different water content and particle sizes were investigated after tribocharging with three kinds of organic polymers to clarify the effects of tribo‐material and particle property on triboelectric separation (TES). The surface composition of wheat bran tissues was also analyzed in situ by Raman micro‐spectroscopy to confirm their triboelectric series. The results showed the tribo‐materials could reverse the separation behaviors of wheat bran tissues. Due to differences in charge amounts, aleurone and intermediate layer (IL) particles showed the similar separation behaviors contrasting that of the outer pericarp. On the basis of the separation behaviors and the results of surface composition analysis, a triboelectric series of wheat bran tissues could be deduced as follows: (+) starch &gt; polyamide &gt; aleurone &gt; IL &gt; outer pericarp &gt; polyethylene &gt; PTFE (−). Moreover, drying of bran particles could improve the separation selectivity and effectivity of TES, but decreasing the particle size of bran tissues merely increase the yields of the enriched fraction obtained by TES.Practical ApplicationsTriboelectric separation (TES) is a green and sustainable dry fractionation for enriching nutritional cereal products, such as wheat aleurone, protein, and glucans. However, a suitable mechanism to improve its efficiency by choosing the tribo‐material and processing wheat bran particles before TES remains unclear. In this study, the separation behaviors and triboelectric series of wheat bran tissues were obtained to guide the selection of tribo‐materials for cereal products. Also, the separation feasibility of a cereal product by TES can be estimated based on the surface composition analyzed by situ Raman micro‐spectroscopy. The results about the pretreatment of starting material, including optimizing of water content and particle size, can contribute to the application of TES in separating cereal and food products.

Effect of Wholewheat Flour Particle Shape Obtained by Different Milling Processes on Physicochemical Characteristics and Quality of Bread

SUMMARYResearch backgroundWholewheat flour is a very good source of nutritional compounds and functional ingredients for human diet. However, it causes negative effect on bread quality. Different milling techniques can be used to obtain wholewheat flour, minimizing the negative effect of both bran and germ on bread quality. The aim of this work is to study the effect of particle size and shape of wholegrain flour on the interaction among the different components, water distribution, dough rheology and bread volume.Experimental approachWholewheat flour of three varieties (Klein Rayo, Fuste and INTA 815) was obtained in cyclonic, hammer and roller mills. The characteristics of wholewheat flour were explored, and the water distribution and rheological properties of dough were determined by thermogravimetric analysis and Mixolab test, respectively. Finally, microscale bread was prepared.Results and conclusionsThe amount of water-soluble pentosans, damaged starch and wet gluten was affected by the milling procedure. Regarding dough rheological properties, wholewheat flour obtained in hammer mill had the lowest water absorption capacity and the highest developing time. This result could be mainly attributed to particle shape in these samples with large amount of endosperm attached to the bran, hindering protein unfolding. Thermogravimetric analysis showed that both fine and large bran particle size seem to have the same effect on water properties in wholewheat dough during heating. Bread made with Klein Rayo variety had the highest specific volume, indicating that wheat with high protein content and breadmaking quality is needed to make wholewheat bread. The results of this work showed that particle shape, rather than particle size, affected the quality of wholewheat flour for breadmaking.Novelty and scientific contributionThe effect of milling type and particle shape of the wholewheat flour had a greater effect than the wheat variety. Thus, the wholegrain milling process should be carefully selected taking to account the shape of the produced particle. This may open new opportunities for developing wholewheat bread with better acceptance by consumers.

Chemical composition and selected quality characteristics of new types of precooked wheat and spelt pasta products

New types of precooked pasta products have been developed based on refined and wholegrain wheat and spelt flours. The resulting dry pasta was then assessed for chemical composition, including amino acids composition, phenolics content, as well as antioxidant activity. The precooked pasta quality was also evaluated for starch gelatinization degree, physical properties, hardness, color profile of dry and hydrated pasta, and sensory characteristics. We found that the application of the extrusion-cooking technique for wheat and spelt pasta processing allows to achieve instant products with good nutritional characteristics and high degree of gelatinization, as well as attractive quality and sensory profiles. Microstructure showed compact and dense internal structure with visible bran particles if wholegrain flours were used. Wholegrain wheat and wholegrain spelt precooked pasta were characterized by better nutritional composition and greater antioxidant potential, but lower firmness and increased adhesiveness when compared with refined flours.

Storage stability, micronisation, and application of nutrient-dense fraction of proso millet bran in gluten-free bread

This study aimed to valorise the underutilised by-product of proso millet decortication. Millet bran was sieved into three fractions with substantially different nutritional profile. The fraction with diameter <500 μm had the highest nutrient density (14% protein, 26% starch, 36% dietary fibre, 9% fat, and 3 mg GAE/g phenolics (d.w.)) and was analysed for oxidative stability, micronisation effect under cryogenic or ambient conditions (2, 4, 8, 12 min), and baking applicability. The bran was oxidatively stable under refrigerator conditions for 150 days. Micronisation slightly increased the antioxidant activity measured by FRAP and ABTS assays as well as the content of fibre soluble in water and 78% ethanol as the bran particle size decreased from 171 μm to 26–46 μm. Gluten-free bread containing 10% of the nutrient-dense fraction of millet bran had higher dietary fibre (76%) and phenolics content (117%), improved volume and crumb softness, regardless of the bran particle size (diameter of 50th percentile 171 vs. 26 μm).

Effect of micronised oat bran by ultrafine grinding on dietary fibre, texture and rheological characteristic of soft cheese

SummaryThe purpose of this research was to study the effect of micronised oat bran on dietary fibre, textural and rheological of soft cheese. The soft cheese was processed by using the different particle size oat bran as fibre supplement, and its dietary fibre content, rheological and textural properties were determined. The results show that the micronised oat bran with 5–30 μm particle size was prepared by ultrafine grinding and passed through 60–400 mesh sieves. The soluble dietary fibre content in micronised oat bran soft cheeses was higher than that of the control (untreated oat bran soft cheeses; P &lt; 0.05), with a maximum of 2.65 g per 100 g cheeses when oat bran was ultrafine crushed and passed through 300 mesh sieves, while the content of insoluble dietary fibre was lower than that of the control (P &lt; 0.05). The micronised oat bran soft cheese in fermentation is a typical non‐newtonian fluid. G′, G″ and apparent viscosity of soft cheeses were increased with the reduction of oat bran particle size. The chewiness and springiness of micronised soft cheeses were increased with the reduction of oat bran particle size, and were higher than that of the control (P &lt; 0.05). The hardness and cohesiveness of micronised soft cheese were decreased with the reduction of oat bran particle size, the hardness was lower, but the cohesiveness of micronised soft cheese was higher than that of the control (P &lt; 0.05). The 1% micronised oat bran can obtain better processing characteristics and overall acceptability for cheese products.

Impact of particle size on wheat dough and bread characteristics

There was studied dough made from refined white and brown wheat flours of different granulometry by means of mechanical, thermal analysis and rheological testing. Observed results were confronted with textural properties of breads. Obtained data confirmed that fine refined white flour dough had high ability to elongate and accumulate stress, in contrary, brown fine flour dough exhibited weaker ability to accumulate stress. Observed increase of the complex viscosity associated with the gelatinization was the fastest in coarse dough, where it gained also the highest peak viscosity. The highest water content liberated was found from fine brown flour bread. This triggered lower water availability for hydration of starch granules in the bread during baking process, thus promoting higher moisture loss affecting thus the overall expansion and porosity of the bread matrix. The latter effect was ascribed to the presence of bran particles in brown flour.

Development of a low-fat, high-fibre snack: effect of bran particle sizes and processing conditions

The influence of fine and medium wheat bran (WB) particle sizes on process and quality parameters of a cereal fried dough (magwinya) was investigated. Magwinya is a snack that resembles, but different from doughnut and it is commonly consumed in most Sub-Saharan African countries. The effect of WB, fermentation and frying time was investigated on weight, diameter, volume, colour, hardness, fat, ash, and moisture, contents of magwinya. Further investigation on mineral and fibre contents as well as the consumer acceptance of optimised samples was also carried out. Predictive models were generated from responses with all lack of fit values >0.1, R2 values ≤0.99 and desirability function of 0.82 and 0.78 for fine and medium WB, respectively. Close agreement between experimental and predicted values for fat and ash was found. The linear, quadratic and interaction effects of process variables significantly (p < 0.05) increased ash, hardness, lightness and moisture and reduced volume and fat content of magwinya. incorporation of 15 g WB, dough fermentation time of 71.66 min (fine WB) and 76.43 min (medium WB) and 3 min frying time significantly (p < 0.05) reduced fat content of magwinya by 44.96% and 22.92%, respectively, and increased ash by 50.41% and 54.20%, respectively. Fine WB resulted in the least fat content while medium WB increased the ash and minerals.