Effects of Milling Methods on Rice Flour Properties and Rice Product Quality:A Review

High-quality rice flour is the foundation for the production of various rice-based products.Milling is an essential step in obtaining rice flour,during which significant changes occur in the physicochemical and quality characteristics of the flour.Although rice flour obtained through mainstream wet milling methods exhibits superior quality,low production efficiency and wastewater discharge limit the development of the industry.Dry milling,on the other hand,conserves water resources,but adversely affects flour performance due to excessive heat generation.As an emerging powder-making technique,semi-dry milling offers a promising solution by enhancing flour quality and reducing environmental impact.This is achieved by minimizing soaking time through hot air treatment while reducing mechanical energy consumption to reach saturated water absorption levels.However,continuous production remains a challenge.This comprehensive review summarizes the effects of various milling technologies on rice flour properties and product qualities.It also discusses key control indicators and technical considerations for rice flour processing equipment and processes.

Effects of milling methods on rheological properties of fermented and non-fermented dough

The rheological properties of wheat flour are very important for the production of bakery products,and the milling methods greatly influence the rheological properties.In this paper,we measured the particle size distributions,damaged starch contents,granular morphology,and pasting properties of the wheat flour,also carried out the uniaxial elongation test,the texture profile analysis,and rheological properties of the dough to evaluate effects of two milling methods,i.e.impact mill(IM)and hammer mill(HM),on the rheological properties of wheat flour and dough.The results showed that milling methods had no significant effects on flour pasting temperature(except the flour H3 obtained by HM grinding three times)and springiness of dough.Flour samples milled by IM had a lower damaged starch content,higher trough viscosity,higher final viscosity and higher values of setback compared to samples processed by HM.After repeated milling of IM,the damaged starch content of the endosperm granules could be controlled below 1%(P<0.05).There was a gap between H1 and H2 in the elastic modulus value of the non-fermented dough group,and the difference increased after fermentation,which was more obvious in the values of viscosity modulus.The more the milling times,the greater the elastic and viscosity modulus of dough of flour processed by both IM and HM.

Photocatalytic activity of Lu^(3+)/TiO_2 prepared by ball milling method

Ball milling method was applied to prepare Lu^3＋/TiO2 photocatalysts. The catalysts were characterized with X-ray powder diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, UV-visible diffuse reflectance spectra（UV-vis DRS）, energy dispersive X-ray spectrometer（EDS）, transmission electron microscopy（TEM） and Brunauer-Emmett-Teller（BET） method. The photocatalytic activities were determined by the degradation of methylene blue（MB） equipped with a 300 W medium pressure mercury lamp. Results show that the first order reaction rate constants of Lu^3＋/TiO2 and pure TiO2 are0.0565 and 0.0263 min-1, respectively, which both were evaluated under the condition of catalysts loading of 0.2 g/L,initial concentration of 25 mg/L for MB, mole ratio of Lu^3＋/TiO2 of 1.5% and milling time of 4 h. The average crystal sizes of 1.5 mol% Lu^3＋/TiO2 and pure TiO2 are 18.7 and 19.3 nm, respectively.

Determination of residual stress distribution combining slot milling method and finite element approach

Residual stress plays a vital role in the structural strength and stability. The determination of residual stress at single-point has become mature at present. However, the method to determine residual stress distribution is still in shortage. For this problem, a finite element approach combined with slot milling method was developed in this study. In the method, firstly a slot is milled on the specimen surface to release the residual stress and then the released displacement field is measured by optical method, such as digital image correlation （DIC）, finally the finite element approach is used to determine the residual stress distribution along the slot. In order to verify the feasibility of the method, it was applied to study the residual stress introduced by shot peening, mainly about the stress distribution along the direction vertical to the shot peened surface. Since the influence depth of shot peening was too small, we utilized focused ion beam （FIB） to determine the microscale residual stress distribution. The result measured by X-ray diffraction （XRD） demonstrated that the method was feasible to determine the residual stress distribution.

EQUIVALENT NORMAL CURVATURE APPROACH MILLING MODEL OF MACHINING FREEFORM SURFACES

A new milling methodology with the equivalent normal curvature milling model machining freeform surfaces is proposed based on the normal curvature theorems on differential geometry. Moreover, a specialized whirlwind milling tool and a 5-axis CNC horizontal milling machine are introduced. This new milling model can efficiently enlarge the material removal volume at the tip of the whirlwind milling tool and improve the producing capacity. The machining strategy of this model is to regulate the orientation of the whirlwind milling tool relatively to the principal directions of the workpiece surface at the point of contact, so as to create a full match with collision avoidance between the workpiece surface and the symmetric rotational surface of the milling tool. The practical results show that this new milling model is an effective method in machining complex three- dimensional surfaces. This model has a good improvement on finishing machining time and scallop height in machining the freeform surfaces over other milling processes. Some actual examples for manufacturing the freeform surfaces with this new model are given.

Choice of reference surfaces for machined surface roughness in milling of SiC_p/Al composites

In order to choose the appropriate reference surface on the machined surface roughness of Si Cp/Al composites, the cutting experiments of Si Cp/Al composites were carried out, and the machined surface topography was measured by OLS3000 Confocal laser scanning microscope. The 3D measured data of machined surface topography were analyzed by the area power spectrum density. The result shows that the texture of machined surface topography in milling of Si Cp/Al composites is almost isotropic. This is the reason that the values of Rq at different locations on the same machined surface are obviously different. Through the comparison of performance of different filtering methods, the robust least squares reference surface can be used to extract the surface roughness of SiC p/Al composites effectively.

Effects of low melting point metals(Ga,In,Sn) on hydrolysis properties of aluminum alloys

Low melting point metals（Ga, In, Sn） as alloy elements were used to prepare Al-In-Sn and Al-Ga-In-Sn alloys through mechanical ball milling method. The effects of mass ratio of In to Sn and Ga content on the hydrolysis properties of aluminum alloys were investigated. X-ray diffraction（XRD） and scanning electron microscopy（SEM） with energy disperse spectroscopy（EDS） were used to analyze the compositions and morphologies of the obtained Al alloys. The results show that the phase compositions of Al-In-Sn ternary alloys are Al and two intermetallic compounds, In3 Sn and In Sn4. All Al-In-Sn ternary alloys exhibit poor hydrolysis activity at room temperature. Al-In-Sn alloy with the mass ratio of In to Sn equaling 1：4 has the highest hydrogen yield. After Ga is introduced to the ternary alloys, the hydrolysis activity of aluminum alloys at room temperature is greatly improved. It is speculated that the addition of Ga element promotes the formation of defects inside the Al alloys and Ga-In3Sn-In Sn4 eutectic alloys on the alloys surface. Al atoms can be dissolved in this eutectic phase and become the active spots during the hydrolysis process. The small size and uniform distribution of this eutectic phase may be responsible for the enhancement of hydrolysis activity.

Effects of Doped Elements on Electrochemical Performance of Ni(OH)_2 Materials

High energy ball milling （HEBM） method was applied to synthesize Ni （OH）2 with different doped elements sub-stitution for Ni^2＋. The morphology, structure and electrochemical behavior of prepared powders were studied. The re-suits reveal that all the synthesized Ni（OH）2 particles were in sub-micron sizes and greatly agglomerated. Co-, Mg-,Fe- or Mn-doped Ni （OH） 2 was of β-phase with 0.400-0.500 nm crystal interlayer distance, while A1- and Zn-doped products displayed a-phase with larger crystal interlayer spaces. The electrochemical mechanisms of synthe-sized Ni（OH）2 electrodes were discussed by EIS spectra. The specific capacity of Co-doped Ni （OH）2 is 245 mA·h · g^-1, i. e. , 60 mA· h · g^-1 higher than that of Al-doped electrode, which has the highest discharging plat-form of a mid-voltage of 1.30 V.

Utilization of waste wool fibers for fabrication of wool powders and keratin:a review

Wool fiber contains approximately 95%keratinous proteins,which is one of the most abundant sources of structural protein.However,a large amount of wool waste is underutilized.Developing appropriate approaches to recycle wool waste and produce value-added products is vital for sustainable development and reducing environmental burden.Thus,this paper reviews the mechanical methods of fabricating wool powder,including pan milling,combined wet and air-jet milling,steam explosion,freeze milling,and three-stage milling.The influencing factors of shape and size,structure,and properties are highlighted to overview of the possible controlling methods.Then,this review summarizes various chemical methods for the extraction of wool keratin,underlining the dissolution efficiency and the structure of wool keratin.Furthermore,the application of reused wool particles in textile,biosorbent,and biomaterials are also reported.Finally,several perspectives in terms of future research on the fabrication and application of wool particles are highlighted.