Flour Streams Research Articles

Analysis of quinoa roller millstreams: Physical, chemical, and functional properties

The objective of present study is to assess the performance of roller milling on quinoa grains, aiming to produce distinct mill stream fractions from perisperm and evaluate its composition and functionalities. During the roller milling process, quinoa yielded three break and three reduction flour streams, as well as coarse bran, fine bran, and germ. Among flour streams, C1 accounted for 49.61% while C2 represented 23.62% of total straight run flour (SRF). Notably, quinoa flour streams exhibited brighter colour and finer granulation similar to wheat flour. Content of ash, protein, and fat increased with successive break flour streams (B1 to B3), displaying a similar trend for reduction flour streams (C1 to C3). Starch damage was higher for last reduction flour streams. Roller milling of quinoa resulted in distinct flour streams from the perisperm, showing physical properties similar to wheat flour. These mill streams varied in yield, nutritional properties, and flour functionalities.

A comprehensive assessment of microscopic characterization techniques to accurately determine the particle size distribution of roller-milled yellow pea flours

The particle size of milled ingredients influences the quality and texture of manufactured foods. However, the limited understanding of how milling influences particle size distribution (PSD) of pulse flours, has hindered the incorporation of pulses in food formulations. This first-ot-its-kind study delves into PSD examination of roller-milled yellow pea flour streams and blends, employing laser diffraction (LD), scanning electron microscopy (SEM), and synchrotron-based X-ray microcomputed tomography (SR-μCT). LD analysis revealed a multimodal distribution pattern across particle sizes ranging from 3 to 1300 μm. SEM confirmed particle size variations among flour streams and blends. Synchrotron X-rays, known for their high intensity, brightness, and tunable energy, provided seminal insights into complex flour structures. Employing SR-μCT, the 3D volumetric particle size distribution yielded more accurate particle size and shape computations than established techniques. This pulse flour characterization will enable food manufacturers to utilize nutrient-dense pulse ingredients to address the growing market demand for health-conscious products.

Physicochemical, rheological, and baking properties of wheat flours from different mill streams

AbstractBackground and ObjectiveWheat is one of the most produced cereal grains in the world, predominantly consumed as bread and other baked products. The roller mill system, which produces different stream flours, is the most commonly used size reduction method for wheat. This study aims to comprehensively examine the physicochemical properties, rheological behavior, and bread‐baking performances of individual mill streams. Flours from 15 different mill streams, along with straight‐grade flour, were collected from a pilot‐scale flour mill and thoroughly analyzed.FindingsThe results showed that the protein and ash content of the flours increased as they passed from the first to last pairs of rolls, while the moisture content decreased. All the flours collected showed poor bulk flowing properties. Rheology analysis revealed that flours from the break system had better mixing properties compared to that from the reduction system, and this trend was also observed in bread‐baking quality. Rheological properties of 4M (4th middling's) and 5M (5th middling's) flours were extremely poor, comparable to gluten‐free flour characteristics. The bread loaves produced by 3BK (3rd break) and 4BK (4th break) showed larger volumes, while 4M and 5M yielded poor‐quality bread. Principal component analysis indicated that lactic acid ‐SDS‐retention capacity can serve as a better predictor of the baking property of wheat flour compared to current methods.ConclusionOur study shows that different flour streams have significantly different dough properties and baking application functionalities. Appropriate flour streams may be pooled for specific end‐uses (e.g., pizza, bread, noodles, pretzels, and cookies).Significance and NoveltyThis study highlights the significance of better understanding wheat flour characteristics for enhancing the overall baking quality, specific end uses, and consumer satisfaction. This study will serve as a blueprint to improve wheat flour testing for baking purposes.

The Wheat Starchy Endosperm Protein Gradient as a Function of Cultivar and N-fertilization Is Reflected in Mill Stream Protein Content and Composition.

Within the wheat starchy endosperm, the protein content increases biexponentially from the inner to outer endosperm. Here, we studied how this protein gradient is reflected in mill fractions using three cultivars (Claire, Apache, and Akteur) grown without and with N-fertilization (300 kg N ha-1). The increasing protein content in successive break fractions was shown to reflect the protein gradient within the starchy endosperm. The increasing protein content in successive reduction fractions was primarily due to more aleurone contamination and protein-rich material being harder to reduce in particle size. The miller's bran fractions had the highest protein content because of their high sub-aleurone and aleurone content. Additionally, the break fractions were used to deepen our understanding of the protein composition gradient. The gradient in relative gluten content, increasing from inner to outer endosperm, was more pronounced without N-fertilization than with and reached levels up to 87.3%. Regarding the gluten composition gradient, no consistent trends were observed over cultivars when N-fertilization was applied. This could, at least partly, explain why there is no consensus on the gluten composition gradient in the literature. This study aids millers in managing fluctuations in the functionality of specific flour streams, producing specialized flours, and coping with lower-quality wheat.

Effect of streaming process on the quality of wheat (Triticum aestivum L.) kernel during extraction

Streaming is a process of routing wheat flour streams to produce flour products and continuing with the milling process using plan-sifters. This machine has six ranges of opening mesh that produce six-grain granulations divided into several flour streams. This study aimed to assess the streaming process effect on the quality changes of wheat kernel extraction. The triplicates observation was conducted on the same 56 flour streams with different multi-wheat blends. The ash, protein, moisture, and gluten quality of blended wheat were analyzed. The streaming process significantly changed grain quality (p<0.001). Increasing the mesh width in the streaming process increased ash content (p<0.05) and protein content (p<0.05). In addition, there was a decrease in water content (p<0.05) and gluten content (p<0.05) at a wider mesh opening. The streaming process produces more than 72% wheat flour. This study showed the vital role of the streaming process in the quality determination of wheat flour produced.

FORMATION OF WATER ABSORPTION CAPACITY OF FLOUR ON MILLS OF DIFFERENT PRODUCTIVITY

This article presents the results of a study of the quality indicators of flour streams, which affect the formation of the water absorption capacity of the final flour. The studies were carried out on five mills with a productivity of 60 to 300 tons per 24 hours. With the help of an original technique for removing the quantitative balance of the milling process, the yield of each individual flour stream and the yield of the final flour were determined, which depended on the productivity of the mill and varied from 75.9-76.1% – for mills with low productivity to 79.0-80.6% – for mills with productivity above 150 tones per 24 hours. Significant changes in the quality indicators of flour streams have been established. During milling at the mill plant with productivity of 150 t / 24 h ash content increased from 0.39% to 2.21%, protein content – from 11.0% to 17.4%, starch damage – from 17.6 UCD to 32.5 UCD. As result the water absorption capacity increases during the milling process from 54.0 to 69.6%. The variation in ash content, protein content, starch damage and other properties of the mill streams are due to the anatomical parts they come from, as result it influence the quality of the final flour. A simple correlation analysis carried out made it possible to evaluate the effect of ash content, protein content, and damaged starch content on the evolution of water absorption capacity. The variations of starch damage and ash content in the flour streams seems to be the principal factor of the increase in water absorption variation, while protein content has the least influence. Despite fluctuations in flour quality indicators on individual systems, it was found that strongly determines the overall quality of the final flour is the mill stream flour yield. That’s why optimization of grinding and sieving modes of systems (B1, B2, C1, C2, B3, Siz1) which have flour streams with the highest yield and the greatest impact on the grinding process is a fundamental step in achieving the set values for the final flour quality indicators. Knowledge and understanding of the patterns of change on individual systems of values of flour yield and their quality indicators that affect water absorption capacity will allow to more effectively manage the water absorption capacity. This will make it possible to optimize the properties of the dough according to the requirements of specific technological lines and to regulate the quality of the finished product at bakery and confectionery enterprises.

PRODUCTION OF SPECIFIC FLOUR FOR FROZEN PRODUCTS BY FLOUR STREAMS BLENDING

The bakery industry requires specific quality flours to manufacture different products. For the production of frozen products, strong flour with specific quality indicators is required, which is caused by the deterioration of the structural and mechanical properties of the dough after defrosting, decrease in the gas–holding capacity and dimensional stability of the dough blanks. Based on the literary review and a priori information the following quality indicators are recommended for flour for frozen products: whiteness >54 units, protein content >12.0%, gluten content >28.0%, GDI in the range of 70–80 units, starch damage in the range of 19–22 UCD, WAC >57%, W >260∙10–4 J and P/L ratio in the range of 0.8–1.2.
 Milling process of the wheat generates different flour streams that differ in composition, particle size, functional and baking properties. Furter all flour mill streams are blended in one straight grade (single grade milling) or multiple flour grades (split milling). Research in the article is to investigate the quality indicators of flour mill streams for further formation of specific flour for frozen products. For the research, samples of flour were taken from each milling system of the flow diagram during milling of the two hard red winter wheat samples (HW1 and HW2 with protein content 13.3 and 12.2% respectively).
 Based on the analysis of the quality indicators of flour milling streams and their comparison with the requirements for flour for frozen products, it was established that none of the flour milling streams meets all the flour quality indicators for frozen products – flour streams from systems B3 and B2 have the closest quality indicators. Selected individual flour milling streams that are of great interest as streams for blending for flour for frozen products.
 As a result of comparing the flour quality indicators obtained at various stages of the technological process with the requirements for flour quality indicators for frozen products flour, the optimal percentage of flour patent yield for frozen products составляет 33.2% for HW1 and 20.5% for HW2.

Characterization of wheat flour millstreams for friabilin prevalence and nutrient composition

ABSTRACT In the current study, wheat varieties Inqulab-91 and AS-2002 were milled from a roller mill and analyzed for chemical characteristics through Near Infra-Red spectroscopy. Friabilin was extracted with Triton X-114 buffer and evaluated on sodium dodecyl sulfate polyacrylamide gel electrophoresis against known molecular weight protein standards. Current results show that the chemical constituents and friabilin revealed significant variation and uneven distribution among flour streams. In both wheat varieties, break streams showed higher protein, moisture, gluten, Zeleny and ash values. Inqualb-91 break streams had a higher lipid content than AS-2002 flour streams, but no clear trend was identified. The 15 kDa band was absent in M3, T2, sizing and low-grade flour of Inqulab-91 while the faint band was present in the remaining streams. Among the remaining AS-2002 mill streams, B2, B4, M3, M5, T1, and sizing showed a prominent 15 kDa band, while the rest showed a faint band. Friabilin depicted a positive correlation with all constituents except fat in AS-2002 while a negative correlation with gluten, Zeleny and fat contents for Inqulab-91.

Quality of Pan Bread as Influenced by Milled Flour Stream Blends of Australian and Russian Wheat

Quality of Pan Bread as Influenced by Milled Flour Stream Blends of Australian and Russian Wheat

Investigating the Contribution of Blending on the Dough Rheology of Roller-Milled Hard Red Wheat.

The flour functionality and particle size distribution of wheat flour obtained on roller milling are dependent on the type of wheat, tempering conditions, and milling conditions. In this study, the impact of the tempering conditions (moisture and time) on the chemical and rheological properties of flour from blends of hard red wheat were analyzed. The wheat blends B1-25:75 (hard red spring (HRS)/hard red winter (HRW)), B2-50:50, and B3-75:25, which were tempered to 14%, 16%, and 18% for 16, 20, and 24 h, respectively, were milled using a laboratory-scale roller mill (Buhler MLU-202). Protein, damaged starch, and particle characteristics were influenced by blending, tempering, and milling streams. For all the blends, the protein content varied significantly among the break flour streams; the damaged starch content varied greatly in the reduction streams. The increased damaged starch content of the reduction streams proportionally increased water absorption (WA). Higher proportions of HRS in the blends significantly decreased the pasting temperature of the dough, as measured using Mixolab. Principal component analysis proved that the protein content was the key determinant in particle characteristics, WA, and pasting properties of the flour, especially in blends with a higher proportion of HRS.

Distribution of Arabinoxylans and Their Relationship with Physiochemical and Rheological Properties in Wheat Flour Mill Streams as an Effective Way to Predict Flour Functionality

The aim of the study was to evaluate wheat flour fractions and the relationships between the rheological properties of wheat flour mill streams with arabinoxylans content to predict flour functionality. The tested wheat variety was IS Laudis and an industrial milling station with several roll sections was employed to reach 30 passages of flour streams. Each mill stream fraction was analyzed separately. Several physiochemical (moisture, ash content, falling number, wet gluten content, gluten index, and damaged starch content) and rheological properties were evaluated by means of utilizing various test apparatus and techniques. The total content of non-starch polysaccharides and arabinoxylans, as well as soluble and insoluble fractions were investigated. Results showed significant differences between the mill streams in terms of the content of physicochemical parameters and rheological properties, as well as in soluble and insoluble fractions of non-starch polysaccharides and arabinoxylans. The relationships between the tested parameters and PCA analysis can be useful for millers who can then select and blend several flour streams to obtain a maximum amount of flour with specified characteristics. A better understanding of the origin and function of different fractions and the role of arabinoxylans and their fractions in the milling process will allow the development of wheat flour blends with the desired functionality. Flours from late reduction and sizing passages (C and R) as well as from sorting filter (V) streams showed high ash content as well as T-NSP and T-AX levels, so the final content of NSP in flour blends may be balanced by the application of the proper amount of C6–C7 and R5 stream flours.

Effects of tempering with phosphoric acid and potassium carbonate solutions on microbial load of wheat flour streams and quality properties of flour

The effects of tempering with phosphoric acid (PA) and potassium carbonate (PC) solutions on the microbial load and the quality of wheat flour and fresh noodles (FNs) were studied. With the increase of PA/PC concentration, total plate count (TPC) and mold and yeast count (MYC) of tempered wheat kernels and flour streams decreased significantly (p < 0.05), and 3B and 3M flour streams had the greatest microbial reduction. PA/PC tempering had little effect on grinding characteristics of wheat kernels. Specifically, the whiteness of the obtained straight-grade flour increased and polyphenol oxidase (PPO) activity decreased significantly (p < 0.05) and the pH and acidity changed slightly. RVA and Mixolab showed that the pasting viscosity decreased slightly after PA tempering, and the protein strength increased slightly after PC tempering. The initial microbial quantity and browning rate of FNs made from flour obtained from wheat tempered with PA/PC solutions decreased significantly (p < 0.05) and the texture characteristics of FNs were significantly enhanced (p < 0.05). The results showed that tempering with PA/PC solutions could effectively reduce the microbial content of flour streams without detrimental effects on the quality of flour and FNs.

Sastav mikronutrijenata proizvoda mlevenja tradicionalnih sorti pšenice poreklom iz Srbije

The deficiency of micronutrients in the human diet is widely recognised as a global problem. The objective of this study was to assess the content of two essential minerals, iron and zinc, in milling streams of old heritage wheat cultivars that have not been produced for more than a half-century to discover potential parent lines with high mineral content for breeding. Kernel size of seven Serbian old wheat cultivars was evaluated for ash content, thousand-grain weight and share of specific kernel fractions. Three cultivars, Crnozrna, Rumska Crvenka and Stara Banatka, were selected as the most appropriate for milling and further analysis of mineral content in the milling streams. The cultivars were milled in a laboratory mill to obtain six flour and two by-product streams. At the same time, iron and zinc content was determined on a graphite furnace atomic absorption spectrometer. After mixing all six flour streams obtained from each cultivar, three different flour types were obtained. The flour with the highest ash content was the "1100" type originating from cultivar Stara Banatka, characterized by the highest iron and zinc content (54.9 mg/kg d. b. and 5.407 mg/kg d. b., respectively). It was estimated that consumption of a daily average bread portion (166 g according to national statistical data) made from Stara Banatka flour could provide about 90% of the recommended daily intake for iron. Therefore, Stara Banatka may be a target cultivar for wheat breeders searching for high-iron parent wheat lines.

Milling and differential sieving to diversify flour functionality: A comparison between pulses and cereals

In this study, pulse (pea, lentil) and cereal (barley, oats) seeds were firstly milled into whole flours, which were then sieved into coarse and fine flours. The particle sizes of the three generated flour streams followed a descending order of coarse > whole > fine, consistent with the observation under scanning electron microscopy (SEM). Among the four crops, the three flour streams showed the same rank order of fine > whole > coarse in starch and damaged-starch contents but the opposite order in ash and total dietary fiber contents. Thus, those functional properties closely related to starch occurring in flour, such as L* (brightness), starch gelatinization enthalpy change (ΔH), and gel hardness, followed the same order of fine > whole > coarse. By contrast, protein contents of the three flour streams did not vary in pea and lentil but showed a trend of coarse > whole > fine in barley and oats, which could partially explain generally comparable foaming and emulsifying properties of the three streams of pulse flours as well as an order of coarse > whole > fine in oil-binding capacity (OBC) of cereal flours, respectively. The different particle sizes and chemical compositions of the three flour streams only resulted in a descending order of fine > whole > coarse in the pasting viscosities of the pulse flours but did not lead to such a clear trend in the cereal flours, which could be partly attributable to the different microscopic structures of the pulse and cereal seeds and their corresponding flours. This research clearly demonstrated that particle size, chemical composition, and microscopic structure were important variables determining the specific techno-functional properties of pulse and cereal flours.

Characterization of roller and Ferkar-milled pulse flours using laser diffraction and scanning electron microscopy

Increasing consumer interest in pulse flour-based food formulations has highlighted the importance of flour characterization based on the type (variety) of pulse and milling methods. The objective of the present study was to compare the microstructure of four different pulse flours (chickpea, navy bean, green lentil, and yellow pea) obtained from two milling methods (single-stage Ferkar mill and multi-stage roller mill). Therefore, in the present study, the particle size distribution, protein content, and microstructural characteristics of starch-protein matrices were investigated using laser diffraction, the Dumas method, and scanning electron microscopy. Micrographs depicted that protein bodies were finely distributed in Ferkar-milled flours and straight grade streams of roller-milled flours with similar protein content. The reduction flour stream (possessing the highest protein content) contained more damaged starches than the break flour stream (possessing the lowest protein content) when observed visually. Chickpea starch granules were observed to be highly porous as compared to the starch granules in other pulse flours. Traces of fiber particles were visible in green lentil flours obtained from roller and Ferkar mills. Conclusively, the microstructure and protein content of the pulse flours is influenced by the pulse-type and milling method. Enhanced ingredient functionality obtained from flour fractions will benefit food manufacturers to incorporate pulse flours in food formulations to enhance the nutritional and textural properties of end products.

Effects of tempering with plasma-activated water on total plate count and quality properties of wheat flour

Nonthermal plasma-activated water (PAW) was prepared and used as wheat tempering water. The effects of tempering with PAW on total plate count and quality properties of wheat flour streams were studied. With the extension of plasma activation time, the content of NO3−, NO2− and H2O2 in PAW significantly increased, and pH decreased dramatically (p < 0.05). After tempering with PAW activated for 40 min, total plate counts in bran, low-grade and patent flour were significantly decreased by 68.85%, 60.91% and 27.27%, respectively (p < 0.05). The polyphenol oxidase, lipase and lipoxygenase activities in low-grade flour markedly decreased by 41.27%, 18.07% and 31.42%, respectively, with the treatment of PAW (p < 0.05). Rapid Visco Analyzer results showed a decrease in peak, trough and final viscosity of straight-grade flour. The free sulfhydryl content in straight- and low-grade flour also decreased. Mixolab test showed there was no significant change in dough rheological characteristics of straight-grade flour. Overall, tempering with PAW could be a promising nonthermal technique to decrease the microbial loads of flour without obvious detrimental effects on its processing quality.

Comparison of flour mill stream blending approaches: Linear programming versus ash curve

AbstractBackground and objectivesFlour millers often produce several flour types from a single wheat grist. Consequently, different specifications characterize each flour. For example, French standards specify six different flour types, each classified by ash content. The proportional blending of different flour streams from a single wheat grist achieves the target flour specifications. This study explores the opportunity to improve flour blending using linear programming and compares it to sequential ash curve blending.FindingsLinear programming and ash curve approaches were used to meet specifications for French flour types from a wheat grist milled to produce 10 flour streams, each stream having different flour quality attributes. The first simulation set quantity targets for Types 45, 55, and 65 flour. The balance of the flour went to the lower value Types 80, 110, and 150. The flour type targets were met using Linear Programming. By utilizing the ash curve method, Type 65 flour was under‐delivered. The second simulation aimed to maximize income using the two methods with no constraints on the amount of each flour type. The linear programming approach resulted in a 0.13% increase in revenue compared to the ash curve technique.ConclusionIn the first simulation, the linear programming technique reduced the lower‐value high ash flour types, generating an additional $6.16/ton of flour. In the second simulation, linear programming increased income by $0.84/ton of flour. Thus, a milling plant operating for 8,000 hr/year and processing 20 tons of wheat/hr translates to $779,000 and $107,000 per annum, respectively.Significance and noveltyThis study showed that linear programming could significantly improve flour blending outcomes, resulting in increased profitability and resource utilization in the milling industry.

Physicochemical and rheological properties of Australian and Russian wheat flour mill streams

AbstractBackground and objectivesThe physicochemical and rheological properties of flour mill streams obtained from the normal milling process of two wheat types were studied. Flour mill streams from consecutive milling processes (breaking, dividing, and reduction stages) differed in their overall technological functionality.FindingsFor both Australian and Russian wheat types, break streams had higher moisture and ash contents than did reduction streams. Ash content increased with progressively increasing break and reduction streams. Likewise, protein and fat contents increased with successive break streams (B1–B5) and reduction streams (C5 and C6). The results for both wheat types indicate that the progressive milling of break and reduction mill streams led to a marked decrease in flour gluten index. For both wheat types, the reduction flour streams had higher levels of damaged starch than did the break section flour streams. The break section flour streams had a higher α‐amylase activity than did the reduction flour streams.ConclusionsRheological properties illustrated a wide range of dough properties between the different break and reduction streams of Australian and Russian wheat types.Significance and noveltyThe present study was applied on flour mill streams at large‐scale milling. Also, fat content of the investigated mill streams is somewhat novel.

Impact of milling on the functional and physicochemical properties of green lentil and yellow pea flours

AbstractBackground and objectivesPulse flours with different particle sizes are available for food production. The effect of varying milling techniques on the quality characteristics of green lentil (GL) and yellow pea (YP) flours was investigated.FindingsUsing a Ferkar mill (one‐step vertical knife mill) caused wider distribution and bigger particle size in all flours than milling with a roller mill. The highest starch damage (3%), starch content (57%), but lowest protein content (22%) were found in YP break flours produced by roller milling. Foaming stability of pulse flours decreased to 51%–71% after 120 min. Lowest viscosities were determined in Ferkar milled flours during pasting. There was no difference in protein strength of GL flours; however, starch gelatinization was found the highest in Ferkar milled flours. In vitro starch digestibility and in vitro protein digestibility‐corrected amino acid score were not affected from milling type within each pulse type.ConclusionDifferent flour streams and different milling technologies caused changes in various flour characteristics. However, the particle size of roller mill flours was similar in each pulse type.Significance and noveltyThe obtained results are a crucial step in better understanding the functional properties and possible food applications of pulse flours according to different milling streams and particle sizes.

Rheological Properties of Individual Triticale Flour Streams

The use of processed products of unconventional grain crops, such as triticale, in various sectors of the food and processing industry is currently attracting more and more attention from both researchers and manufacturers in the Russian Federation...