Dielectric properties of wheat flour mixed with oat meal

2013 ◽  
Vol 27 (2) ◽  
pp. 175-180 ◽  
Author(s):  
D. Łuczycka ◽  
A. Czubaszek ◽  
M. Fujarczuk ◽  
K. Pruski
Keyword(s):  
Electromagnetic Field ◽  
Dielectric Loss ◽  
Wheat Flour ◽  
Loss Factor ◽  
Ash Content ◽  
Dielectric Loss Factor ◽  
Field Frequency ◽  
Impedance Analyzer ◽  
Sedimentation Value

Abstract Possibilities of using electric methods for determining admixtures of oat meal to wheat flour, type 650 are presented. In wheat flour, oat meal and mixtures containing 10, 20 and 30% of the oat meal, moisture, protein, starch and ash content, sedimentation value, yield and softening of wet gluten were determined. In samples containing 0, 5, 10, 15, 20, 25, 30 and 100% of oat meal, the dielectric loss factor and conductivity were determined using an impedance analyzer for electromagnetic field frequency ranging from 0.1-20 kHz. It was found that the dielectric loss factor varied for tested material. The best distinguishing between tested mixtures was obtained at the measuring electromagnetic field frequency of 20 kHz. The loss factor was significantly correlated with the yield of wet gluten and the sedimentation value, parameters indicating the amount and quality of gluten proteins in flour.

Microwave Nondestructive Sensing of Moisture Content and Water Activity of Almonds

2021 ◽  
Vol 64 (4) ◽  
pp. 1373-1379
Author(s):  
Samir Trabelsi
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Moisture Content ◽  
Bulk Density ◽  
Water Activity ◽  
Free Space ◽  
Loss Factor ◽  
Dielectric Loss Factor ◽  
List Type

HighlightsMoisture and water activity were determined nondestructively and in real time from measurement of dielectric properties.Moisture and water activity calibration equations were established in terms of the dielectric properties.Situations in which bulk density was known or unknown were considered.SEC ranged from 0.41% to 0.68% for moisture and from 0.02 to 0.04 for water activity.Abstract. A method for rapid and nondestructive determination of moisture content and water activity of granular and particulate materials was developed. The method relies on measurement of the dielectric constant and dielectric loss factor at a single microwave frequency. For the purpose of illustration, the method was applied to predicting the moisture content and water activity of almond kernels. A free-space transmission technique was used for accurate measurement of the dielectric properties. Samples of Bute Padre almond kernels with moisture content ranging from 4.8% to 16.5%, wet basis (w.b.), and water activity ranging from 0.50 to 0.93 were loaded into a Styrofoam sample holder and placed between two horn-lens antennas connected to a vector network analyzer. The dielectric properties were calculated from measurement of the attenuation and phase shift at 8 GHz and 25°C. The dielectric properties increased linearly with moisture content, while they showed an exponential increase with water activity. Situations in which the bulk density was known and unknown were considered. Linear and exponential growth regressions provided equations correlating the dielectric properties with moisture content and water activity with coefficients of determination (r2) higher than 0.96. Analytical expressions of moisture content and water activity in terms of the dielectric properties measured at 8 GHz and 25°C are provided. The standard error of calibration (SEC) was calculated for each calibration equation. Results show that moisture content can be predicted with SECs ranging from 0.41% to 0.68% (w.b.) and water activity with SECs ranging from 0.02 to 0.04 for almond kernel samples with water activity ranging from 0.5 to 0.9 and moisture contents ranging from 4.8% to 16.5% (w.b.). Keywords: Bulk density, Dielectric constant, Dielectric loss factor, Free-space measurements, Loss tangent, Microwave frequencies, Moisture content, Water activity.

scholarly journals Inversion of Oil-Immersed Paper Resistivity in Transformer Based on Dielectric Loss Factor

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 44050-44058 ◽  
Author(s):  
Jiangjun Ruan ◽  
Yiming Xie ◽  
Shuo Jin ◽  
Yu Shi ◽  
Yu Tian ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Loss Factor ◽  
Dielectric Loss Factor

Research on Aging Characteristics and Chemical Composition of Hydrogenated Transformer Oil

2012 ◽  
Vol 614-615 ◽  
pp. 1131-1137 ◽  
Author(s):  
Xu Dong Ouyang ◽  
Yi Hua Qian ◽  
Wei Su ◽  
Yi Bin Huang
Keyword(s):  
Chemical Composition ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Loss Factor ◽  
Kinematic Viscosity ◽  
Chemical Properties ◽  
Dielectric Loss Factor ◽  
Transformer Oil ◽  
Composition Variation

Under the condition of Baader aging, the chemical composition variation and the effect of transformer oil aging on electrical properties such as dielectric loss factor and physic-chemical properties such as kinematic viscosity were studied during aging. Moreover, the correlation between hydrogenated transformer oil electrical and physic-chemical properties and its chemical composition variation were investigated.

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