• Korean Journal of Food Science and Technology
• /
• v.29 no.4
• /
• pp.693-699
• /
• 1997

The effects of mugwort juice on the gel properties of corn starch (CS), mung bean starch (MS), and potato starch (PS) were investigated. Water holding capacities of three starches were increased with addition of the juice. Solubilities of CS and MS were also increased. Swelling power was increased in CS but decreased in MS. Viscoamylogram showed that 5% addition of the juice lowered the initial gelatinization temperatures of CS and MS, but raised the temperature of PS. While peak viscosities of CS and MS pastes were decreased a little, the viscosity of PS paste was decreased remarkably from 2,280 BU to 845 BU. Addition of mugwort juice did not affect significantly the hardness of starch gels during 7 days of storage at $25^{\circ}C\;and\;4^{\circ}C$. Degrees of gelatinization of the starch gels were affected by addition of the juice, especially in PS, during storage. Freeze-thaw stabilities of three gels were not changed by addition of the juice. The starch gels added with the mugwort juice had smooth surface visually because the crude fibrous materials of mugwort were removed during juice preparation.

• Korean journal of food and cookery science
• /
• v.8 no.1
• /
• pp.1-7
• /
• 1992

Recently, plenty of imported Chinese Mungbean is sold, for Korean Mungbean is expensive. But they say, Chinese Mungean has less delicacy and cooking quality. Above all, in comparison with Korean and Chinese Mungbeans properties they are different - Chinese Mungbean grain is twice in dimension, Chinese Mungbean is white and Korean one is yellow in peeled grain color. They are similar in size shape with the microscope. With Amylograph of Brabender the viscosity of Korean Mungbean is gradually and continually increased until heating from $25^{\circ}C$ to $92.5^{\circ}C$ and cooling to $25^{\circ}C$ again, but the one of Chines Mungbean is increased suddenly in 74$^{\circ}C$ and shows the abrupt break-down phenomenon. This same phenomenon is shown in swelling with melting-pointer, In $25^{\circ}C$, the cooling temperature, Chinese Mungbean is measured to 1400 B.U and Korean one 1600 B.U. With color-meter of Richard S. Hunter, 12% gel of Korean Mungbean starch is clear but Chinese one white. The texture of 12% gel of Chinese Mungbean starch with Rheo-meter becomes hardened much more than Korea one. As a result of sensory-test, color, cohesiveness, and flavors of Korean gel is preferred overwhelmingly.

• Food Science and Biotechnology
• /
• v.16 no.6
• /
• pp.902-909
• /
• 2007

Granular maize starch was treated with Thermus scotoductus 4-${\alpha}$-glucanotransferase (${\alpha}$-GTase), and its physicochemical properties were determined. The gelatinization and pasting temperatures of ${\alpha}$-GTase-modified starch were decreased by higher enzyme concentrations. ${\alpha}$-GTase treatment lowered the peak, setback, and [mal viscosity of the starch. At a higher level of enzyme treatment, the melting peak of the amylose-lipid complex was undetectable on the DSC thermogram. Also, ${\alpha}$-GTase-modified starch showed a slower retrogradation rate. The enzyme treatment changed the dynamic rheological properties of the starch, leading to decreases in its elastic (G') and viscous (G") moduli. ${\alpha}$-GTase-modified starch showed more liquid-like characteristics, whereas normal maize starch was more elastic and solid-like. Gel permeation chromatography of modified starch showed that amylose was degraded, and a low molecular-weight fraction with $M_w$ of $1.1{\times}10^5$ was produced. Branch chain-length (BCL) distribution of modified starch showed increases in BCL (DP>20), which could result from the glucans degraded from amylose molecules transferred to the branch chains of amylopectin by inter-/intra-molecular transglycosylation of ${\alpha}$-GTase. These new physicochemical functionalities of the modified starch produced by ${\alpha}$-GTase treatment are applicable to starch-based products in various industries.

• Food Science and Biotechnology
• /
• v.14 no.6
• /
• pp.871-874
• /
• 2005

The effect of rice starch at different concentrations (0, 4, 6, and 8%) on dynamic rheological properties of surimi sols was investigated by small-deformation oscillatory measurements at $10^{\circ}C$ and during heating from 10 to $95^{\circ}C$. Dynamic frequency sweeps at $10^{\circ}C$ showed that the magnitudes of storage modulus (G') decreased with increasing starch concentration while those of tan $\delta$ increased. G' values of surimi-rice starch sols during heating decreased with increasing starch concentration, indicating that the pattern of G' changes during heating was influenced by the concentration of the added rice starch. In general, the characteristic G' thermograms of all samples showed a similar sol-gel transition pattern.

• Preventive Nutrition and Food Science
• /
• v.11 no.2
• /
• pp.146-154
• /
• 2006

Structural modification of corn starch by gamma irradiation was evaluated for under dry conditions at varied intensities from 0 to 40 kGy. Under scanning electron microscopy, the granule shape of corn starch was not significantly affected by the irradiation up to 40 kGy. In addition, X-ray diffraction and melting patterns of the irradiated starches were similar to those of the native starch, indicating that crystalline regions in the starch granules were not changed by irradiation. However, the pattern of gel permeation column chromatography showed a significant increase in partial hydrolysis of gamma irradiated starch samples. The degree of polymerization and the paste viscosity of irradiated starch samples dose-dependently decreased significantly with irradiation, and increased solubility and clarity were observed in the irradiated starch solution. In addition, the degree of retrogradation decreased as irradiation dose increased. Irradiation of corn starch has advantages over the ordinary acid or the enzyme hydrolysis modification methods. It does not affect the granular shape and crystalline phase of starch during hydrolysis, and the process can be carried out in dry state.

• Korean journal of food and cookery science
• /
• v.7 no.2
• /
• pp.19-23
• /
• 1991

This study was conducted to compare the characteristics of reference starch gel and 5 additives-adding corn starch gels (agar, CMC, pectin, casein, gelatin). The sensory evaluation, textural analysis by Instron Universal Testing Machine were carried out The results were as follows: 1. In sensory evaluation. \circled1 The hardness of agar was significantly higher than that of control and the hardness of pectin was significantly lower than that of control. \circled2 The adhesiveness of CMC and pectin was significantly higher than that of control, and the adhesiveness of agar was significantly lower than that of control. \circled3 In acceptability, CMC and pectin were significantly higher than control and the other samples were not significantly different from control. 2. In textural analysis by Instron. \circled1 The hardness of agar was significantly higher than that of control and the hardness of the other samples was significantly lower than that of control. \circled2 The cohesiveness of agar and casein was significantly higher than that of control and the cohesiveness of gelatin was significantly lower than that of control. 3. In sensory evaluation or instrumental analysis by Instron. It was thought that the best sample-classifying characteristic was hardness.

• KSBB Journal
• /
• v.10 no.2
• /
• pp.166-169
• /
• 1995

Spores of Trichoderma harzianum TCC 52445 for control of Rhlzocronia stem canker on potato were immobilized in various natural matrix, and germination rate and some rheological properties of the spore-matrix complex were Investigated. Germination rate of gelatin gel-spore complex and potato starch gel-spore complex were 2.8% and 2.9%, respectively, but hardness and cohesiveness of the gelstin gel-spoke complex were better than those of potato starch-spore complex. The hardness and cohesiveness were increased when the spores were immobilized in hybrid gelatin gel made by mixing several different types of natural matrix, but decreased their germination rate. Addition of corn steep liquor (1%) as spore nutrient in gelatin gel-spore complex was helpful for increasing the germination rate.

• Applied Biological Chemistry
• /
• v.38 no.5
• /
• pp.403-407
• /
• 1995

For the use of starch gel like Mook(a Korean traditional gel food), the physicochemical properties and gelatinization patterns of defatted high amylose corn starch were investigated. The crude and total lipid contents of starch decreased by defatting from 0.07%, 0.92% to 0.03%, 0.19%, respectively. But iodine affinity increased from 51.6% to 71.3%. Water binding capacity of starches increased from 104.6% to 117.3% after defatting. Soluble carbohydrate and leached amylose of untreated and defatted starches were increased rapidly above $110^{\circ}C$. The apparent viscosity of starch dispersion using alkali solution increased above 0.3N NaOH solution but the transmittance increased above 0.4 N NaOH. The DSC thermograms of both starches showed broad and double endotherm with relatively low enthalpy, but the second peak of endotherm was larger in defatted starch than in untreated starch.

• Korean Journal of Food Science and Technology
• /
• v.23 no.5
• /
• pp.633-641
• /
• 1991

Mook, a traditional gel food in Korea, has been made from mainly acorn, buckwheat, and mungbean starches (Mook Starches). Corn, rice, wheat starches (Non-Mook Starches) are not used due to their weak gelation power. In order to know the effects of properties of starch on gelation, some physicochemical properties, molecular structure, and starch lipid of these six starches were investigated and compared with gel hardness. Both amylose content and gel hardness of starches were in order of mungbean, acorn, buckwheat, wheat, corn, and rice and these two parameters showed a very good correlation (r=0.95). The amyloses of Mook Starches had larger molecular size (${\overline}D.P._{n}=1,080{\sim}1,580\;vs\;670{\sim}1,120$ for Mook Starches and Non-Mook Starches, respectively), more average number of chain ($2.9{\sim}5.4\;vs\;1.7{\sim}2.5$), and shorter average chain length ($290{\sim}390\;vs\;390{\sim}450$) than those of Non-Mook Starches. Also, Mook Starches had longer average chain length ($22.2{\sim}22.6\;vs\;18.9{\sim}21.3$) of amylopectin and less starch lipid content ($0.12{\sim}0.49\;vs\;0.68{\sim}1.26%$) than Non-Mook Starches. These properties had good correlations with gel hardness (r=0.76-0.84). Consequently, the gelation power of Mook Starches was thought to be derived from their high amylose content and other properties of starches.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.30 no.4
• /
• pp.405-411
• /
• 1985

The buffer soluble proteins were extracted from six cultivars of barley grains and analyzed by various electrophoresis; 7.5% polyacrylamide slab gel, 2-30% polyacrylamide porosity gradient tube gel, isoelectric focusing (pH4-9) and starch gel electrophoresis. The proteins, esterase, acid phosphatase, malate dehydrogenase, glutamate dehydrogenase and leucine aminopeptidase were investigated to find out the best method to differentiate barley cultivars. The result were that protein and esterase bands in 2-30% polyacrylamide porosity gradient tube gel electrophoresis and protein bands in 7.5% polyacrylamide slab gel electrophoresis showed typical varietal differences. Therefore, those methods were suitable for differentiation of barley cultivars. It was difficult to differentiate the cultivars by the other methodes and patterns of the other enzymes.