• Korean Journal of Food Science and Technology
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• v.52 no.3
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• pp.220-225
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• 2020

In this study, we investigated the starch characteristics of foxtail millet (FM) and sorghum (SG) cultivars grown in Korea. The amylose contents were 29.42 and 6.42% in the Daname and Samdachal FM cultivars, and 9.09 and 11.11% in the Nampungchal and Sodamchal SG cultivars, respectively. The amylopectin polymerization analysis showed that the highest degree of polymerization (DP) was in the range of DP13-24 for all samples, at approximately 60%. The resistant starch content was very low (<0.10%) among the FM and SG cultivars. The starch gelatinization analysis showed low setback values in the Samdachal and Nampungchal cultivars. The gelatinization enthalpy, calculated based on an endothermic reaction, did not differ significantly between the SG cultivars but was significantly higher in the Samdachal FM cultivars than in the Daname FM cultivars. The results of this study might be used as basic data for the development of FM and SG products.

• Industry Promotion Research
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• v.9 no.2
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• pp.37-44
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• 2024

This study selected the worst-case scenario for fireball and vapor cloud explosion (VCE) of a styrene monomer storage tank installed in a petrochemical production plant and performed damage prediction and accident impact analysis. The range of influence of radiant heat and overpressure due to fireball and vapor VCE during the abnormal polymerization reaction of styrene monomer, the main component of the mixed residue oil storage tank, was quantitatively analyzed by applying the e-CA accident damage prediction program. The damage impact areas of radiant heat and explosion overpressure are analyzed to have a maximum radius of 1,150m and 626m, respectively. People within 1,150m of radiant heat of 4kW/m2 may have their skin swell when exposed to it for 20 seconds. In buildings within 626m, where an explosion overpressure of 21kPa is applied, steel structures may be damaged and separated from the foundation, and people may suffer physical injuries. In the event of a fire, explosion or leak, determine the risk standards such as the degree of risk and acceptability to workers in the work place, nearby residents, or surrounding facilities due to radiant heat or overpressure, identify the hazards and risks of the materials handled, and establish an emergency response system. It is expected that it will be helpful in establishing measures to minimize damage to workplaces through improvement and investment activities.

• Food Engineering Progress
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• v.21 no.2
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• pp.103-109
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• 2017

Alginate lyase from Streptomyces violaceoruber was purified by DEAE sephacel chromatography and SP sepharose chromatography. The specific activity of the purified enzyme was 14.6 units/mg protein, representing a 40.6-fold purification of the crude extract. The final preparation thus obtained showed a single band on Tricine-SDS polyacrylamide gel electrophoresis whose molecular weight was determined to be 23.3 kDa. The polyMG block of sodium alginate was hydrolyzed by the purified alginate lyase and then separated by activated carbon column chromatography and bio gel P-2 gel filtration. The main hydrolysates were composed of hetero type M/G-oligosaccharides with the degrees of polymerization (D.P.) being 6 and 8. To investigate the effects of hetero type M/G-oligosaccharides from the sodium alginate on the growth of some intestinal bacteria, cells were cultivated individually on the modified-MRS medium containing D.P. 6 and 8 M/G-oligosaccharides. B. longumgrew 4.25-fold and 6.44-fold more effectively by the treatment of D.P. 6 and 8 M/G-oligosaccharides compared with those of standard MRS medium. In addition, B. bifidumgrew 3.3-fold and 5.4-fold more effectively by the treatment of D.P. 6 and 8 M/G-oligosaccharides. In conclusion, D.P. 8 was more effective than D.P. 6 hetero M/G-oligosaccharides as regards the growth of Bifidobacteriumspp. and Lactobacillus spp.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.1
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• pp.1-9
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• 2006

Purpose: The purpose of this study was to evaluate the efficacy and substitute possibility of a newly developed flowable composite resins as a luting cement for translucent fiber post. Material & Method: Two kinds of 12 mm translucent fiber Post (D.T. Light-Post (Bisco, USA) and FRC Postec (Ivoclar vivadent, Liechtenstein) was inserted into the teflon mold (7 mm diameter, 9 mm long) and Filtek-Flow (3M ESPE. USA), a light activated flowable composite resin, was polymerized for 60 seconds through the post. Also, the post was cut from the tip to 9 mm, 6 mm, 3 mm, and Filtek-Flow was light cured according to each length. For comparison, 60 seconds light-cured and 24 hours self-cured two dual cured resin cement (Duo-cement (Bisco, USA) and 2 Panavia-F (Kuraray, Japan)) samples were prepared as control group. Also cavities (1 mm in width, 1 mm in depth and 12 mm in length) were prepared using acrylic plate and aluminum bar, and flowable composite resin was flied and light cured by the diffused light from the fiber post's side wall. The degree of polymerization was measured according to the distance from curing light using Vickers' hardness test. Result: Within the limitation of this study, the following conclusions were drawn: 1. Vickers' hardness of light cured dual cured resin cement and flowable composite resin decreased from Panavia-F, Filtek-Flow and Duo-cement accordingly (p<0.05). In the dual curing resin cement, light curing performed group showed higher surface hardness value than self cured only group (p<0.05). 2. Surface hardness ratio (light cured through fiber post /directly light cured) of D.T. Light-Post using Filtek-Flow showed about 70% in the 6 mm deep and about 50% in the 12 mm deep FRC Postec showed only 40% of surface hardness ratio. 3. Surface hardness ratio by diffused light from the post's side wall showed about 50% at 6 mm and 9 mm deep, and about 40% at 12 mm deep in D.T. Light-Post. However, FRC Postec showed about 40% at 6 mm deep, and almost no polymerization in 9 mm and 12 mm deep.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1158-1158
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• 2001

Fast and dynamic biochemical, enzymatic and morphological changes occur during the so-called generative development and during the vegetative processes in seeds. The most characteristic biochemical and compositional changes of this period are the formation and decline of storage components or their precursors, the change of their degree in polymerization and an extensive change in water content. The aim of the present study was to detect the maturation processes in seed nondestructively and to verify the applicability of near infrared spectroscopic methods in the measurement of physiological, chemical and biochemical changes in wheat seed. The amount and variation of different water “species” has been changed intensively during maturation. Characteristic changes of three water absorption bands (1920, 1420 and 1150 nm) during maturation were analysed. It was concluded that the free/bound transition of water molecules could be followed sensitively in different region of NIR spectra. Kinetic changes of carbohydrate reserves were characteristic during maturation. An intensive formation and decline of carbohydrate reserves were observed during early stage of maturation (0 -13 days, high energy demand). An accelerated formation of storage carbohydrates (starch) was detected in the second phase of maturation. Five characteristic absorption bands were analysed which were sensitive indicators the changes of carbohydrates occurred during maturation. Precursors of protein synthesis and the synthesis of reserve proteins and their kinetic changes during maturation were followed from NIR spectra qualitative and qualitatively. Dynamic formation of amino acids and the changes of N forms were detected by spectroscopic, chromatographic and by capillary electrophoresis methods. Calibration equations were developed and validated in order to measure the optimal maturation time protein and moisture content of developing wheat seeds. The spectroscopic methods are offering chance and measurement potential in order to detect fine details of physiological processes. The spectra have many hidden details, which can help to understand the biochemical background of processes.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.8
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• pp.933-945
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• 2011

This research proposes a pattern design method for 24 pleated skirts in order to develop an automatic draft program for pleated skirts that will enhance fit and enable mass production. The research method and results are outlined as follow. 1. Three-dimensional body measurements were conducted on 30 randomly selected women in their 20s. By using 34 body measurement items and 6 types of calculations among the items, the items required in the designing of an original pleated skirt were extracted. They were then interpreted through correlation analysis, variance analysis, a t-test, linear regression analysis and multiple regression analysis. 2. An extra amount was added to the waist measurement and external capsule measurement according to the number of times the pleats coincided and the thickness of the fabric by the degree of polymerization of the horizontal cross section (the test of this research: 0.518mm). The extra amount of waist measurement was 3.6cm while the hip measurement was 4.3cm larger than the hip measurement combined with the external capsule measurement and the extra amount. 3. Based on the ${\pm}$standard deviation/2 as the average of the difference between the external capsule measurement and waist measurement, the subjects were classified into 3 somatotypes. Somatotype 1 presented an average total length of waist darts of 23.6cm while that of somatotype 2 was 26.2cm and that of somatotype 3 was 30.2cm. It has been confirmed that there is a significant difference among somatotypes in the total length of waist darts from the front center to the front side and the total length of waist darts from the side to the back center in terms of the average amount of waist darts for every 12 parts on the WL.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.570-573
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• 2009

The debranching enzyme of Nostoc punctiforme (NPDE) is a novel enzyme that catalyzes the hydrolysis of $\alpha$-1,6-glycosidic linkages in starch, followed by the sequential hydrolysis of $\alpha$-1,4-glycosidic linkages. The debranching activity of NPDE is highly specific for branched chains with a degree of polymerization (DP)>8. Moreover, the rate of hydrolysis of $\alpha$-1,4-linkages by NPDE is greatly enhanced for maltooligosaccharides (MOs) with a DP>8. An analysis of reaction mixtures containing various starches revealed the accumulation of maltooctaose (G8) with glucose and maltose. Based on the novel enzymatic properties of NPDE, an MO mixture containing more than 60% G8 with yield of 18 g G8 for 100 g starch was prepared by the reaction of NPDE with soluble starch, followed by ethanol precipitation and gel permeation chromatography (GPC). The yield of the G8-rich mixture was significantly improved by the addition of isoamylase. In summary, a 4-step process for the production of a G8-rich mixture was developed involving the enzymatic hydrolysis of starch by NPDE.

• The Korean Journal of Food And Nutrition
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• v.31 no.2
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• pp.278-283
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• 2018

The objective of this study was to evaluate quality properties of high quality rice. Seven rice varieties, Dabo, Daebo, Samkwang, Sindongjin, Sukwang, Jinsumi, and Haiami, were investigated for proximate contents and physicochemical characteristics. Moisture content was highest in the Jinsumi (13.13%). Protein and lipid content was highest in the Haiami. The amylose content of the rice cultivars was 20.15~22.51%. The degree of amylopectin polymerization (DP) was analyzed, and in all cultivars, DP 13-24 content was found to be highest, at more than 53%, whereas DP ${\geq}37$ content was lowest, at less than 5.81%. With regard to free sugar, maltose content in rice was the highest (${\geq}46%$). Toyo value of rice was highest in Samkwang, Daebo, and Jimsumi. Palatability characteristics were highest in Daebo and Jimsumi. Thus, the results of this study suggested that Samkwang, Daebo, and Jinsumi can be effectively used as processed cooked rice, though further studies should be required regarding changes in the quality of rice after cooking.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1201-1205
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• 2009

Corn starches with different amylose contents were enzymatically modified using Thermus aquaticus 4-$\alpha$-glucanotransferase ($TA{\alpha}GTase$). Upon the enzyme treatment, the chain-length distributions of isoamylolytically debranched products became broader [degree of polymerization (DP): 3-40] than those of untreated corn starches. In addition, a variety of cycloamyloses (CAs) with different sizes were formed by the glucanotransfer activity of $TA{\alpha}GTase$. CAs with DP 5-40 were detectable in all of the $TA{\alpha}GTase$-treated corn starches. From the results of high-performance anion-exchange chromatography and high-performance size-exclusion chromatography analyses, it was suggested that the amount of CAs produced by the enzyme treatment increased as the amylose content of the starches increased. Thus, we concluded that the extent of modification of starch molecules was enhanced in proportion to amylose content by the transfer activity of $TA{\alpha}GTase$. This finding could be useful for developing an efficient process of CA production using this enzyme.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1232-1238
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• 2004

To investigate the production and characteristics of thermostable levan sucrase from Rahnella aquatilis ATCC 33071, the levan sucrase gene from R. aquatilis was cloned and expressed in Escherichia coli without induction system. Expression of levansucrase gene in E. coli had no notable or detrimental effect on the growth of host strain, and the recombinant levan sucrase exhibited levan synthesis activity. Levansucrase was secreted to the periplasm in E. coli, and addition of $0.5\%$ glycine yielded further secretion of levansucrase to the growth medium and resulted in an increase of total levansucrase activity. Furthermore, the cellular levansucrase was evaluated for the production of levan by using toluene­permeabilized whole-cells. The levansucrase was thermostable at $37^{\circ}C$. The molecular size oflevan was $1{\times}\;10^{6}$ Da, as determined by HPLC, and the degree of polymerization of levan varied with incubation temperatures: Low incubation temperature was preferable for the production of high-molecular size levan. The present study demonstrated that the mass production of levan and levan oligosaccharides can be achieved by glycine supplementation to the growth medium or by toluene­permeabilized whole-cells.