• Journal of the Korean Home Economics Association
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• v.27 no.1
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• pp.39-46
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• 1989

Mung bean starch gel (Mook) and gel made from starch of cowpea are similar properties in texture. In order to elucidate the similarity between these two starch gels, some physicochemical properties of cowpea starch were compared with those of mung bean starch. Water bildings capacity of cowpea starch (183.6%) was a little low than that of mung bean starch (184.2%). The solobility, swelling power and optical transmitance of the cowpea starch showed a smiliar pattern to mung bean starch, but cowpea starch had a little lower solubility than mung bean starch. Amylogram of mung bean strach (4, 5, 6, 7%) shoved no peak viscosity but cowpea starch (4, 5, 6%) showed peak viscosity and both starches showed high viscosities when cooling. Cowpea and mung bean starches had the blue value of 0.41 and 0.47, the alkali number of 8.4 and 8.0, the amylose content of 30.5 and 32.1%, the molecular weight of amylose of 30,000 adn 29,258 and glucose unit per segment of amylopectin of 27.6 and 26.8 respectively. The shape of cowpea and mung bean strach granules were round and elliptical, and the mean vlalue of major axis, minor axis and the ratio of these were 20.7 and 21.8 ${\mu}{\textrm}{m}$, 14.6 and 14.4 ${\mu}{\textrm}{m}$ and 1.42 and 1.51, respectively. The extent of retrogradation determined by the glucoamylase digestion method and syneresis showed that cowpea starch gel was larger than that syneresis showed than cowpea starch gel was larger than that of mung bean starch gel. The redults of X-ray diffraction studies showed A pattern for two starches, Diffraction peak of gels disappeared with gelatinization of starches but that of two starch gels storaged for 2 days at 5$^{\circ}C$ showed a similar patterm.

• Korean journal of food and cookery science
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• v.8 no.1
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• pp.9-14
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• 1992

The morphological properties of acorn starch granules and starch gels were examined with scanning electron microscope and X-ray diffractometer. The shape of acorn starch granule was rounded triangular and some elliptical. The size distribution of starch granule was also analyzed. The mean value of minor axis, major axis and the ratio of those were 4.785 $\mu\textrm{m}$, 7.30 $\mu\textrm{m}$ and 0.68, respectively. The surface micro-structure of acorn starch gels were investigated by SEM. Acorn crude and refined starch gel were very different in surface micro-structure. X-ray diffraction pattern of acorn starch was C-type, and the pattern of acorn starch gels were extremely different because of disintegration of starch granules by gelatinization. The diffraction intensity of acorn refined starch gel was slightly higher than crude starch gel.

• Korean journal of food and cookery science
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• v.24 no.6
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• pp.757-762
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• 2008

In this study, korean wheat composite flour and dough were prepared with 1.5, 3.0, 4.5, and 6% Nelumbo nucifera G. tea powder(NNTP). The samples and a control were then compared qualitatively in terms of moisture, protein, ash, and wet gluten content. The farinogram, amylogram, and extensogram characteristics of the dough were also examined, in order to determine the optimal ratio of NNTP for the formulation. According to our results, the moisture content of the flour decreased with increasing NSPP content, whereas its protein and ash content, resistance, and R/E ratio at 135 min of extensogram increased. The NNTP samples had a significantly higher water absorption and weakness of farinogram and maximum resistance at 45, 90, and 135 min. Additionally, samples had an R/E ratio at 45 min of extensogram, 90 min less than the control group. However, stability of the farinogram, temperature of maximum and maximum viscosity of the amylogram, and extensibility of the extensogram showed the reverse effect. The control and NNTP samples showed significant differences in gelatinization beginning temperature of the amylogram, while development time of the farinogram was not significantly different. With regard to the extensogram characteristics of the dough, the area of the control and 1.5% NNTP increased with increasing testing time, whereas at 3.0, 4.5 and 6.0% NNTP, extensibility, and resistance, maximum resistance, and R/E ratio of control and NNTP samples decreased. An area of 3.0, 4.5 and 6.0% NNTP and extensibility of 1.5% NNTP were not significantly different among the testing times. In conclusion, these results show that 1.5% NNTP may prove very useful as a substitute for korean wheat flour where the production of korean wheat white bread is concerned. It may also provide good nutritional and functional properties.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.626-631
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• 1993

The effects of mugwort on some physicochemical properties of rice flour, on the viscosity of rice flour pastes (2 and 4%), on the hardness and the freeze-thaw stability of rice flour gels (20 and 40%), and on the degree of gelatinization (DG) of pastes and gels were investigated. By addition of mugwort, water holding capacity, swelling power, and solubility of rice flour were increased. The rice flour pastes became thicker by addition of mugwort, but viscosities of both the rice flour pastes and the rice flour-mugwort pastes, without noticeable difference between them, were decreased during storage at $25^{\circ}C\;and\;4^{\circ}C$ for 7 days. The rice flour gels became firmer by addition of mugwort and hardnesses of both the rice flour gels and the rice flour-mugwort gels were increased during storage, especially at $4^{\circ}C$. DGs, measured by glucoamylase digestion, of pastes and gels were decreased slightly during storage. Freeze-thaw stability of gels was not affected by addition of mugwort.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.747-753
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• 2013

The physicochemical properties of sweet potato (SP) starches reclaimed from an SP-processing sludge without freezing (RC/NF) and with freezing (RC/FR) were investigated. Lab-isolated (LI) SP starch, as a control, were prepared from raw SP. RC/NF and RC/FR SP starches were recovered from SP-processing sludges by the repeated sieving and washing procedure. The total starch contents and amylopectin branch-chain distributions did not differ for three SP starches. Relative to LI and RC/NF SP starches (possessing similar physicochemical characteristics), the apparent amylose and phosphorus contents, swelling factor, and pasting viscosity were reduced for RC/FR SP starch. However, the freezing treatment altered X-ray diffraction pattern (at $5.5^{\circ}$, $11-12^{\circ}$, and $24^{\circ}$ $2{\theta}$) of RC/FR SP starch, which likely increased its gelatinization peak and completion temperatures. Its amorphous region in total diffractogram was reduced, resulting in the enhanced relative crystallinity. Overall results suggested SP starches recovered from an SP-processing sludge would have the potential to replace commercial SP starch products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.596-602
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• 1993

The Characteristics of Shinsunchalbyeo(Japonica) and Hangangchalbyeo($J{\times}Idica$) starches including physicochemical properties, differential scanning calorimetry(DSC) and enzymatic digestion of lintnerized starches were investigated. Degree of hydrolysis of Hangangchalbyeo starch with 2.2N HCI for 48hr was higher than that of shinsunchalbyeo starch. Absorbance at ${\lambda}_{max}$ 680nm, and ${\lambda}_{max}$ of iodine stained starch decreased upon acid treatment. But water binding capacity, swelling power and solubility considerably increased as hydrolysis progressed. Relative crystallinity of two starches increased with acid treatment, and that of Shinsunchalbyeo starch was higher than that of Hangangchalbyeo starch. DSC data continuously decreased for lintnerization periods, and those of Shinsunchalbyeo starch. DSC data continuously decreased for lintnerization periods, and those of Shinsunchalbyeo starch have higher than those of Hangangchalbyeo starch. The onset temperature of starch by DSC continuously decreased by treatment, but conclusion temperature increased until 24hr and then decreased. The enthalpy for gelatinization decreased for both starches. Degree of hydrolysis of lintnerized Shinsunchalbyeo starch with glucoamylase was slightly higher than that of Hangangchalbyeo starch.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.321-325
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• 2008

This study was carried out to examine the effects of wheat flour ferment cultured by Lactobacillus acidophilus on the physical characteristics of cooked noodle. Different scanning calorimeter(DSC) analysis results for noodle gelatinization showed that the noodles containing flour ferment had higher enthalphy values than the control noodle. And based on the degree of retrogradation for the noodles containing the flour ferment, enthalpy decreased as the amount of the ferment increased, resulting in the delay effect on the retrogradation. According to textural property evaluations over a storage period, the noodles containing the flour ferment had increases in hardness and cohesiveness, and the springiness of the control group was higher than that of the noodles containing the flour ferment; however, this difference between groups gradually disappeared with increasing storage time. Finally, the noodles containing 10% flour ferment had a higher overall preference score than the control group, indicating that the addition of the flour ferment during noodle production can have a beneficial effect on the preference.

• Applied Biological Chemistry
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• v.25 no.3
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• pp.119-125
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• 1982

Using piston type extruder, barley flour was extruded at various processing conditions, The used variables were three shear rates (apparent shear rate 118, 534, $1169sec^{-1}$), four extrusion temperatures(90, 120, 150, $180^{\circ}C$) and three moisture contents (15, 25, 35%). The rheological properties and the extrudate quality were monitored in extrusion. Barley flour showed pseudoplastic behavior having average power law index 0.28 in used shear rate range. When viewed from general appearance, die swell, density, water uptake, rehydration swell and gelatinization degree of extrudate, $25{\sim}35%$ moisture and $120^{\circ}C$ temperature was suitable processing condition for noodle-like product, and 25% moisture and $150^{\circ}C$ temperature was good for snack or flake product. Moisture content of the extrudate can be pretty well estimated from energy balance at higher temperature and higher moisture content.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.392-398
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• 1983

A pilot single-screw food extruder was constructed, and its mechanical properties and product characteristics were investigated by using corn grits. The screw rotational speed was varied and the changes in temperature profile of the barrel for the start-up period of operation were measured. The rate of heat generation for the start-up period was affected by the screw speed and feed rate. The screw speed resulted in a great influence on the estimated dough viscosity. The changes in the dough viscosity could indicate the on-set of termoplastic reaction in the barrel. The expansion ratio during the start-up period mainly depended on the barrel temperature and the degree of thermoplastic reaction in the barrel. The barrel temperatures for the gelatinization and burning of corn grits depended on the screw speed as well as the feed rate.

• Korean journal of food and cookery science
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• v.8 no.3
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• pp.291-296
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• 1992

The physicochernical properties of Korean buckwheat starches were investigated. The results were as follows; 1. Water binding capacity of kangwon hull buckwheat starch was 106.55% and that of Kangwon rice buckwheat was 99.35%. 2. The pattern of change in swelling power of hull buckwheat starch for increasing temperature started to increase at 60$^{\circ}C$ and increased rapidly from 80$^{\circ}C$, and that of rice buckwheat increased slowly from 60$^{\circ}C$ to 90$^{\circ}C$. 3. The ranges of gelatinization temp. of hull buckwheat and rice buckwheat starches were 70~75$^{\circ}C$ and 75~85$^{\circ}C$, respectively. 4. The blue value of hull buckwheat starch and rice buckwheat starch were 6.25 and 0.62, respectively. 5. The alkali number of hull buckwheat starch and rice buckwheat starch were 1.28 and 3.68 respectively. 6. The amylose content of hull buckwheat and rice buckwheat starch were 32.26% and 38.09%. 7. Periodate oxidation of hull buckwheat starch resulted that amylose had me average molecular weight of 103, 004, degree of polymerizatlon of 572 and amylopectin had me degree of branching of 7.64, glucose unit per segment of 13.09, and periodate oxidation of rice buck wheat starch resulted mat amylose had me average molecular weight of 125, 654, degree of polymerization of 698 and amylopectin had degree of branching of 6.59, glucose unit per segment of 15.16.