• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.118-124
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• 1998

Dehulled cowpea was microparticulated and coarse fractions and fine fractions were collected by air classification at air classifying wheel speed (ACWS) of 15,000 rpm, 12,000 rpm and 9,000 rpm, respectively. Protein content in fine fraction after air classification was 2 times higher than that of microparticulated cowpea, emulsion capacity was about 3 times than coarse fraction. The coarse fraction of the highest viscosity on the gelatinization properties were detected by amylograph, was C-3 (9,000 rpm coarse)fraction. The majority of microparticulated cowpea particles were oval shaped starch and the rest of them were indeterminate minute particles which had some sharp corners. As an application test, microparticulated cowpea and coarse fraction (C-3) were used for mook (Korea traditional starch jelly) preparation and the wet milled cowpea starch was compared as a control. Some impurities induced discoloring was detected by sensory evaluation but after washing, it made no difference in sensory scores between washed starch and the control cowpea mook. And also syneresis of washed cowpea was less than control. At the above result, it can be to recovery about 85% of cowpea starch using microparticulation/air classification technology.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.1008-1012
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• 1995

Glutinous rice was microparticulated and air-classified at different air classifying wheel speeds (ACWS) of 20,000 rpm and 15,000 rpm in a Turboplex classifier. The starch was concentrated to a coarse fraction and the protein was shifted to a fine fraction. The degree of starch damage of the coarse fraction was comparable to that of traditionally soaked glutinous rice. Yoogwa(Korean cracker) made from the fractions of $ACWS\;15,000{\sim}20,000\;rpm$ and below ACWS 15,000 rpm was very comparable to that made by the traditional method in degree of puffing, hardness and internal structure. It was also confirmed by the sensory evaluation, indicating that the microparticulation/air classification technology could be applied to produce raw material of Yoogwa. The developed noble process could exclude the long soaking step in the traditional Yoogwa process and reduce the pretest time remarkably.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.497-505
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• 1996

Defatted soybean meal (DSM) was microparticulated at cut-off whell speed of 9.000 rpm and air-classified into fine and coarse fractions at air classifying wheel speeds (ACWS) of 21,000, 18,000, 15,000 12,000 and 9,000 rpm stepwisely. Protein and ash content increased while lipid, carbohydrates and dietary fiber content decreased with decreasing ACWS. Amino acid composition and amino acid content of defatted soybean meal were similar to those of raw soybeans with aspartic and glutamic acid, the major amino acids. The yield and particle size increased with decreasing ACWS and mean particle size ranged from $4.9{\mu}m$ to $14.2{\mu}m$. The particles were oval-shaped with sharp corners. Water holding capacity, oil holding capacity and emulsion capacity slightly decreased with decreasing ACWS. Soybean curds formed showed different characteristics depending on the coagulant used and on the substitution ratio of full fat soybean flour with microparticulated DSM. Microparticulated DSM could successfully substitute wheat flour up to 10% level without bring no-ticiable beany flavor in the cakes.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.506-513
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• 1996

Soybean hull was microparticulated at cut-off wheel speed of 9,000 rpm and air-classified into fine and coarse fraction at air classifying wheel speeds (ACWS) of 10.000, 15,000 and 20,000 rpm. respectively. Proximate analysis of the coarse and fine fractions of the microparticulated/air-classified soybean hull showed that ash, protein and lipid were enriched in the coarse fractions and carbohydrates in the fine fraction. Dietary fiber were enriched in coarse fractions and dietary fiber and dietary fiber content increased with decreasing ACWS. Mean particle size of fine fractions ranged from $3.1{\mu}m\;to\;5.5{\mu}m$ that of coarse fractions ranged from $9.9{\mu}m\;to\;20.0{\mu}m$ and both increased with decreasing ACWS. The particles were mostly oval-shaped regardless of the fractions. Generally the fraction of low ACWS showed higher viscosity. In water holding capacity, oil absorption and emulsion capacity, there was significant difference between coarse and fine fractions while there was no significant difference as a function of different ACWS. Oil absorption of flying batter was decreased significantly in the fraction of ACWS 15,000. when cakes and cooking were prepared partially substituted with soybean hull fraction, there was no significant changes on their physical and sensory properties up to 10% substitution.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.769-774
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• 1993

Defatted rice bran was microparticulated using fluidized bed opposed jet mill and air-classified at different air classifying wheel speed (ACWS) in Turboplex classifier. The median particle size and the standard deviation decreased, and concomitantly the specific surface area increased generally with increasing ACWS. The protein, fat and ash contents of the recovered rice bran increased with ACWS. The contents of minerals; magnesium, zinc, iron and manganese; increased positively with ACWS. The phytic acid content, however, was slightly higher at middle ACWS. The dietary fiber content was highest in the ACWS 15,000 rpm fraction showing 31.47%. Higher ACWS resulted in lighter colored powder. The water holding capacity (WHC) showed the maximum value at ACWS 12,000 rpm and decreased with increasing ACWS, while the oil holding capacity (OHC) increased with ACWS. The rheological property of the microparticulated rice bran/water suspension fitted to the linear model. The yield stress and viscosity of the suspension increased with ACWS. The shape of microparticulated rice bran at ACWS 21,000 rpm was spherical, and the median particle size was $3.7{\mu}m$. When cake was prepared with substitution of microparticulated rice bran at 5%, the cake height and volume increased remarkably.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.596-602
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• 1994

To separate and concentrate mucilage from yam(Dioscorea batatas DECNE), yam was dried, microparticulated using impact mill and air-classified at different air classifying wheel speed(ACWS) in classifier. As ACWS increased from 5,000 rpm to 22,500 rpm, the contents of dietary fiber, protein and lipid of air classified microparticles(ACM) increased remarkably. Especially the ACM with ACWS over 15,000 rpm showed 36.41% dietary fiber and 16.66% protein. The dietary fiber and protein components were concentrated to $2.5{\sim}9.0$ times as compared with whole yam powder. Concomitantly the non-fibrous carbohydrate decreased from 88.31% to 16.84. The damaged starch(%), WSI and WAI of ACM of ACWS over 15,000 rpm were $1.5{\sim}3.0$ times higher than those of ACM under ACWS 15,000 rpm. The apparent viscosity of ACM was 0.0800 Pa s over ACWS 15,000 rpm and 0.0080 Pa s under ACWS 15,000 rpm. Judging from viscosity of ACM, the mucilage component of yam was concentrated to 10 times. In conclusion, the optimum process to separate and concentrate the mucilage from yam consisted of the microparticulation to $5{\sim}30{\mu}m$ and the air-classification at ACWS over 15,000 rpm.