Stone Mill Research Articles

Effects of particle size on quality characteristics of stone-milled whole wheat flour.

Whole wheat flour (WWF) prepared by the direct crushing method preserves all the components of the whole wheat grain. WWF with different particle sizes (180, 150, 125, 106, and 96 μm) was obtained by combining stone milling and particle size sieving technology. The effects of particle size on the proximate composition, farinograph, pasting, thermal, and functional properties, starch microstructure, and Fourier-transform infrared (FTIR) spectroscopy of stone-milled WWF were investigated. The smaller the particle size of WWF, the higher the damaged starch content. The water absorption, degree of softening, pasting temperature, solubility, and syneresis of WWF increased steadily as the particle size decreased, whereas the peak viscosity, final viscosity, swelling power, water holding capacity, and enthalpy of gelatinization decreased. The scanning electron microscope micrographs revealed that the larger the particle size of WWF, the denser the distribution of starch granules. The β-sheet and β-turn contents of WWF with particle size 180 μm were the highest, reaching up to 33.85% and 39.79%, respectively. The particle size exerted influence on the quality characteristics of stone-milled WWF, and the overall properties of WWF were better at medium particle size. © 2023 Society of Chemical Industry.

Milling and roasting impact pasting and rheological properties of oat flours and quality of steamed oat cakes

Roasting is the traditional heat treatment of oat kernels before milling in China. The effects of roasting and milling methods on the physicochemical properties of oat flour and the quality of the steamed oat cake have not been explored. Roasting treatment caused a looser structure of the oat grain, which made the oat grain easier to crush. Stone milling induced severe damage (92 g/kg) and aggregation of starch granules, resulting in the highest total starch hydrolysis rate of oat flour and the highest total gas volume of raw oat batter. However, the pore expansion capacity was restricted, resulting in the minimum specific volume and the highest hardness of steamed oat cake. Ultrafine milling produced a more uniformly particle size distribution of raw and roasted oat flour and the steamed oat cake prepared with ultrafine-milled raw oat flour had the maximum specific volume and minimum hardness, 2.75 mL/g and 6.01 N. Pulverizer milling resulted in the lowest solubility index and the lowest starch hydrolysis rate of raw and roasted oat flour. Raw whole oat flour prepared by ultrafine milling or pulverizer milling gave softer steamed oat cakes with higher volume or slower starch degradation, respectively.

Transactional Leadership, Well-Being Support, OCB-Altruism, and Employee Performance: Testing Their Relationship

This study analyzes the relationship between transactional leadership, well-being support, OCB-altruism, and employee performance. Data was collected from 212 respondents who worked in the 11 stone milling companies in Central Java Province - Indonesia. By using AMOS 24 software in processing and analyzing the data, the results of this study found that (1) transactional leadership has a positive and significant effect on employee performance; (2) well-being support has a positive and significant effect on employee performance; and (3) OCB-altruism has a positive and significant effect on employee performance. Employees who have high OCB-altruism have a strong psychological attachment to the organization that encourages them to contribute to the organization both formally and informally by displaying their best performance.

Virtual skeletons and digital muscles: an experimental bioarchaeological approach to the pre-Hispanic production of millstones (Tenerife, Canary Islands)

Highlights: The combination of biomechanical analysis and open-access Kinovea software enables the study of musculoskeletal and articular wear of experimentally reproduced tasks. The repeated use of the right arm during indirect percussion and abrasion in lithic production could increase the changes in bone robusticity of specific muscle attachments observed in the osteoarchaeological record. Motion ranges and postural angles analysis can generate more accurate representations of "virtual humans" in their archaeological context. Abstract: Understanding the physical impact of ancient labours has become an important experimental bioarchaeology area. Complex motion capture systems and digital tools have been used in biomechanical analysis during the reproduction of manual tasks. However, these systems are costly, so the researchers have explored alternative digital solutions. Therefore, the open-access Kinovea software was checked to confirm its reliability in characterizing the physical loads associated with particular works of ancient times. In this case study, the authors have analyzed the central postural angles and muscle chains involved in the indigenous manufacturing process of rotary stone mills, in the high mountains of Tenerife. The study included a virtual motion capture analysis carried out during the different phases of the experimental reproduction of this process; it was defined from the archaeological record of the quarries-workshops of Las Cañadas del Teide National Park (Canary Islands, Spain) volcanic millstones. The results of this study have demonstrated the software's effectiveness to virtually analyze the significant differences in posture between work techniques, observing a predominance of the use of m. biceps brachii, the m. brachioradialis, and the elbow joint during the manufacture of stone mills. On the other hand, Kinovea also has excellent potential in virtual archaeology, giving users tools to generate the average postural angles. As a result, building "virtual skeletons" in more precise work postures has been possible. This may serve as the base element to create complete body representations in virtual environments.

KAJIAN PROSES PENGOLAHAN COKELAT BATANGAN (CHOCOLATE BAR) DI PT XYZ DI KOTA KENDARI - SULAWESI TENGGARA

This study aims to determine the processing process of chocolate bars in PT XYZ Kendari City - Southeast Sulawesi. The data was collected using observation, interviews, and documentation and then analyzed using qualitative and descriptive approaches. The results showed that the chocolate processing process at PT XYZ Kendari City begins with the post-harvest stage then the next stage is the processing of cocoa paste and chocolate bars and then the cocoa processing process, namely filtering cocoa beans, peeling the cocoa shells using the NSS (Nib Shell Separator), grinding nib into a coarse paste using a stone mill, grinding coarse paste into a fine paste using a ball mill 30, then mixing the chocolate dough in a mixer, mashed chocolate dough using a mini ball mill, molding chocolate using a tempering machine, freezing chocolate into the freezer, and chocolate bar packaging.

Influence of Refining and Conching Systems on Rheological and Sensory Properties of Chocolate

There are different refining systems on the market and knowing the differences between these systems can help choose equipment according to the needs of each chocolate manufacturer. This work aimed to evaluate different technologies for the chocolate refining stage and evaluate the impacts on the physical, chemical and sensory characteristics of the chocolates produced. We evaluated the following refining systems: System 1: Double refining; System 2: Refining in ball mill; System 3: Refining in ball mill and BLC conching; System 4: Refining and conching in refining conche; System 5: Refining and conching in stone mill – melanger; System 6: Simple refining. All of these refining systems were evaluated for pH, total titratable acidity, moisture, maximum particle size, particle size distribution, rheology, and sensory characteristics. The refining and conching system resulted in considerable changes in the evaluation of features such as total titratable acidity, moisture, maximum particle size, particle size distribution, and rheological properties. In the sensory evaluation, attributes such as aroma, hardness, melting, and color did not show significant differences. On the other hand, we observed significant differences in attributes such as overall impression, flavor, grittiness, and acidity. It was possible to conclude that the combination of refining systems with homogenizing conche can be favorable for obtaining chocolates due to greater fluidity and better results in sensory evaluation.

Transformational Leadership and Innovative Work Behavior: Testing the Mediating Role of Knowledge Sharing and Work Passion

Organizations face very complex challenges to achieve survival and competitive markets. Therefore, this study mainly aims to examine the impact of transformational leadership on innovative work behavior while considering the mediation role of knowledge sharing as well as work passion in work situations. A total of 201 responses were received from the participants working in stone milling companies in Central Java-Indonesia, and 193 questionnaires were taken into account for the analysis. This study tested the whole model via a path analysis utilizing SmartPLS 3.0. The results indicated that transformational leadership directly did not significantly impact innovative work behavior. However, transformational leadership positively and significantly impacted knowledge sharing and work passion. In addition, knowledge sharing and work passion positively and significantly impacted innovative work behavior. This finding signifies that knowledge sharing and work passion mediated the association between transformational leadership and innovative work behavior.

Effect of different mills on the physical and flow properties of selected black bean flour particle size fractions

AbstractBackground and ObjectivesParticle size and shape can influence inherent flour properties and eventually the quality of the finished food product. The objective of this study was to determine the effect of mill type on the physical and flow properties of selected particle size fractions of black bean flour.FindingsParticle shape differed with mill type and particle size. Disc mill and stone mill produced flour particles with lower circularity and greater elongation than did hammer mill, cyclone mill, and centrifugal mill. Greater particle elongation with a stone mill and disc mill is attributed to compression/shear size‐reduction forces applied to the particles trapped between the rotating/nonrotating stones or discs. Particle circularity increased with an increased particle size, which was reflected by a strong positive correlation between circularity and particle size (r = .93, n = 5) while elongation value was negatively correlated with average minimum particle size (r = −.90, n = 5). Particle circularity had a negative correlation of r = −.93, n = 30; r = −.81, n = 30; r ≈ −.95, n = 30; r = −.94, n = 30 with L*, angle of repose, angle of slide, and compact bulk density, respectively.ConclusionsMill type and particle size interaction significantly affected the physical and flow properties of selected particle size fractions of black bean flour. The results indicate that the large black bean particles were more circular and compact and less convex and elongated compared with small particles.Significance and NoveltyThese findings indicate that mill type affects not only particle size but also particle shape, both of which can affect the flow and functional processing properties of black bean flour.

Stone Milling versus Roller Milling in Soft Wheat (Part 2): Influence on Nutritional and Technological Quality of Products.

Wholegrain soft wheat flours can be obtained by either roller milling or stone milling. In this paper, we report on the continuation of a study aimed at analysing compositional and technological differences between differently milled wholegrain flours. Eight mixes of soft wheat grains were stone milled and roller milled and the milling products analysed for their phytic acid, lipids composition to determine the presence of trans-fatty acids and damaged starch. A wholegrain flour milled with a laboratory disk mill was also analysed as comparison, as well as seven wholegrain flours purchased on the market. For phytic acid we found that that there is no compositional difference between a stone milled or a roller milled flour if the milling streams are all recombined: the milling streams instead have different amounts of phytic acid which is mainly present in the fine bran and coarse bran. It was not possible to highlight differences in the milling technology due to the presence of trans-fatty acids in the stone milled wholegrain flour whereas it was possible to find that starch damage depended on the milling method with stone milled wholegrain flours having in all cases significantly higher values than the roller milled ones.

Removal of Stone Cells From Guava Nectar

Several methods have been investigated for reducing the grittiness of guava nectar caused by the presence of stone cells. Of the several methods tried, which included nitration, centrifugation, cyclone separation, and particle-size reduction using a colloid mill and a stone mill, centrifugation and treatment in the stone mill proved to be the best. When the nectars are centrifuged in a solid-basket centrifugal, the grittiness was completely eliminated, since the stone cells responsible for this grittiness are separated during the process. Nectars of similar quality were prepared by size reduction of the stone-cell particles in a stone or mustard mill. A comparison of both methods showed that higher yields of nectar are obtained when the stone mill is used to disintegrate the stone cell, but some discoloration results when pink-colored fruit is treated thus. Treatment in the stone mill also results in a higher loss of vitamin C when compared to the loss that results when the nectars are centrifuged.

An improved QPSO-SVM-based approach for predicting the milling force for white marble in robot stone machining

Milling force prediction is one of the most important ways to improve the quality of products and stability in robot stone machining. In this paper, support vector machines (SVMs) are introduced to model the milling force of white marble, and the model parameters in the SVMs are optimized by the improved quantum-behaved particle swarm optimization (IQPSO) algorithm. A set of online inspection data from stone-machining robotic manipulators is adopted to train and test the model. The overall performance of the model is evaluated based on the decision coefficient (R2), mean absolute percentage error (MAPE) and root mean square error (RMSE), and the results obtained by IQPSO-SVM are superior to those of the PSO-SVM model. On this basis, the relationship between the milling force of white marble and various machining parameters is explored to obtain optimal machining parameters. The proposed model provides a tool for the adjustment of machining parameters to ensure stable machining quality. This approach is a new method and concept for milling force control and optimization research in the robotic stone milling process.

Functional drink powders from vertical-stone-milled oat and highland barley with high dietary-fiber levels decrease the postprandial glycemic response

• Vertical stone mill was used to get oat and highland barley bran powder (SOB and SHB) • Two drink powders (SOB-D and SHB-D) were obtained from SOB and SHB by extrusion. • SOB-D and SHB-D had lower in vitro starch hydrolysis, higher RS level than control. • SOB-D and SHB-D had lower glycemic response than a wheat bun in healthy subjects. • Higher breath H 2 level via consuming SOB-D and SHB-D was observed in healthy subjects. To extend the application of oat and highland barley in the food industry, a vertical stone mill was first used to process two bran powders (SOB and SHB). Compared with commercial flours, SOB and SHB were more thermally stable with higher protein and dietary fiber levels while lower starch content. Furthermore, two drink powders (SOB-D and SHB-D) were extruded from SOB and SHB, with significantly increased resistant starch (the highest value 6.3% in SHB-D). Starch-protein complexes were detected in both SOB-D and SHB-D, inducing lower in vitro digestibility and human postprandial glycemic response than those of wheat flour steamed bun. Human Intake of SOB-D and SHB-D elevated the level and extended duration of breath H 2 , indicating stronger colonic fermentation. It identified combination of vertical stone milling and extrusion was an effective way to produce oat and highland barley functional food with low digestibility and high potential of colonic fermentation ability.

Research on machining error prediction and compensation technology for a stone-carving robotic manipulator

Stone-carving robotic manipulators (SCRMs) have a broad range of applications due to their high efficiency, diverse processing capabilities, and strong flexibility. However, due to its weak rigidity, the milling accuracy of an SCRM is lower than that of a computer numerical control (CNC) machine for working stone into special shapes, making it difficult to meet the requirements of stone milling processing. To improve the milling accuracy of SCRMs, multi-iteration error compensation technology considering the coupling relationship between compensation and deformation is proposed in this paper. First, a global stiffness model of an SCRM in which the robot arm bars are regarded as flexible links is established, and the relationship between the milling force and milling depth is fitted based on a milling force prediction model. Then, the machining error and milling depth when processing a marble workpiece are predicted. Finally, a multi-iteration method is applied for calculation using an interval correction strategy to construct a discrete control system for error compensation in the SCRM. The feasibility and effectiveness of the proposed compensation technology are verified by an experiment using the KUKA-240-2900 SCRM system.

Flat Linear Induction Motor in the Electric Drive of a Milling Plant with Rotating Millstones

Flour is a food product; therefore, it is essential to preserve the maximum minerals and vitamins in its production. The study aims to increase the productivity and energy efficiency of the stone mill electric drive. The paper analyses different motors for the stone mill electric drive and introduces a Flat Linear Induction Motor (FLIM). Its design includes an inductor and a secondary element (rotor), a rotating disk with attached millstones. This motor is simple to manufacture and reliable in operation. The paper considers the rational decisions of the stone mill with the FLIM electric drive. A mathematical model was developed, an experimental milling plant with the FLIM was studied to assess the stone mill efficiency. A FLIM, unlike a rotation motor, involves end effects that can be effectively used in the stone mill, in particular, for millstone vibration during their rotation. Stone mills with the FLIM electric drive will allow launching efficient and energy-saving production machines on the world market for producing whole-grain flour in individual production.

Chemical and Physical Characterization of Sorghum Milling Fractions and Sorghum Whole Meal Flours Obtained via Stone or Roller Milling.

Due to climate change sorghum might gain widespread in the Western countries, as the grain is adapted to hot climate. Additionally sorghum contains a notable amount of health-promoting nutrients. However, Western countries do not have a long history of sorghum consumption, and thus little experience in processing it. Milling systems in these areas were mostly developed for wheat or rye milling. In the present work, the effectiveness of sorghum milling when using a stone and a roller milling system (pilot scale) was investigated as well as its impact on the chemical and physical properties of the obtained flour fractions and whole-grain flours. Results showed that both milling systems could be successfully adapted to producing chemically and physically distinct flour and bran fractions from the small sorghum kernels. Fractions with increased bran material that contained higher amounts of ash, protein, fat, total dietary fiber, and total phenolic content but less starch, showed enhanced water absorption indices and water solubility indices. Interestingly, no significant difference was found in the ash and fat content of the different fractions obtained from stone milling. Overall, the study provided information on the production and composition of distinct flour fractions, which offer a wider range of future food applications.

Milling method affects the physical properties of black bean flour

AbstractBackground and objectivesDry bean milling has attracted interest due to the increased need for nonwheat ingredients available for food applications. The objective of this study was to examine the physical and flow properties of black bean flour produced using a variety of laboratory mills and mill settings.FindingsFlour from mills which utilized screens (cyclone mill, centrifugal mill, and hammer mill) showed significantly different characteristics than flour from mills without a screen (disk mill and stone mill). Geometric mean size of flour particles was negatively correlated with starch damage (r = −.92), L* (r = −.94), angle of repose (r = −.94), and angle of slide (r = −.80 to −.90, depending on surface material) and positively correlated with moisture content (r = .72) and loose bulk density (r = .72). Finely ground flour resulted in particles that tended to be less circular and more elongated and had high angles of repose and slide.ConclusionsMilling method significantly affected (p < .05) physical and flow properties of black bean flour.Significance and noveltyThese findings can be used by food processors in selecting a milling method that favors the production of black bean flour with the desired physical properties.

ANÁLISIS DEL PROYECTO PARA LA INSTALACIÓN DE UN MOLINO DE PIEDRA EN LA CANTERA DE CABEZAS, UNIÓN DE REYES

This article is carried out in the Base Business Unit (UEB) Cantera de Cabezas, belonging to the Business Group of the Construction Materials Industry, with the aim of: analyzing the start-up of an investment project in the installation of a stone mill to obtain marl powder. The methods and techniques used are to study of the demand and the feasibility of the project, direct observation, Gantt chart. With the application of the aforementioned methods it was obtained as a result that with the installation of the stone mill the production of marl powder (coco) is increased, a total management of the generated waste is guaranteed and the duration of the project is 7 months and 4 days with a total cost of $ 45817.92. For the implementation of the techniques, were used tools such as Microsoft Office, Visio 2010, Project Professional 2010 and EndNote X8.

Occupational health and safety management case study: Establishment of PM10 Contour map

Atmospheric dust is a significant air pollution problem. Particulate matter is small solid particles floating in the air. It is caused by objects that have been smashed, hit, crushed, and crushed until they break down into small parts. When blown by the wind, it will spread in the air. And fell to the ground the fall time is slow or fast depending on the dust particles' weight. Dust is divided into large dust, including small dust called PM10 (dust with a diameter from 10 microns down). The stone mill problem has been a long-time problem. Many related government agencies try to fix the problem of dust pollution and health safety. PM10 disperse from the source to the community nearby the stone mill was measured by the low-cost dust monitoring device. The result found that the 24-hour mean PM10 particulate matter was 0.090 mg/m3, which was also lower than the statutory permissible 24-hour Mean PM10 at no more than 0.12 mg/m3. The PM10 dust contour map can be used for health risk management planning, primarily to mitigate the pollution to the community environment and their health under some usage limitations changes.

Efficiently production of micron-sized polyethylene terephthalate (PET) powder from waste polyester fibre by physicochemical method

Polyester has the highest share of world fibre market, which also leads to a large volume of polyester waste. In this study, a compact process combining alkali treatment and stone milling was used to recycle waste polyester fibre into ultrafine powder efficiently. The morphology of the original polyester fibre, alkali modified fibre and milled polyester powder were observed by Scanning electronic microscopy (SEM) and atomic force microscope (AFM). The particle size, crystallinity and strength loss were also studied. It was found that the alkali treatment greatly reduced fibre strength and the crystallinity of the fibre largely decreased after stone milling. The waste polyester fibre was converted into micron powders easily and efficiently. About 700 g dry ultrafine powders with particle size of around 60 µm were achieved in 2 h. This method shows a great potential for industrial application of waste polyester in the future.

Study on endoscopic urinary stone milling device using opposite phase vibration

Study on endoscopic urinary stone milling device using opposite phase vibration