• Food Science and Biotechnology
• /
• v.17 no.2
• /
• pp.234-240
• /
• 2008

The optimal conditions for the production of branched dextrin from com starch (CSBD) using branching enzyme (BE) were established by investigating the degree of retrogradation of the gelatinized starch. The physicochemical properties of CSBD prepared using the established process were evaluated. It was found that physicochemical properties of com starch were greatly modified by BE treatment. CSBD had a higher dextrose-equivalent value and water solubility than the corresponding control. On the other hand, the viscosities in gelatinized solution and amylose contents of CSBD were lower than those of the control. A high-performance size-exclusion chromatography/multiangle laser light scattering/retractive index (HPSEC/MALLS/RI) system showed that the average molecular weight of CSBD was lower than that of the control. The pasting viscosities of CSBD were stable during the entire temperature cycle. In general, the BE treatment resulted in the retrogradation during storage being lower for CSBD than for the control.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.2
• /
• pp.129-134
• /
• 2014

Two neuropeptides were purified from the acidified tube feet extract of the starfish Asterias amurensis by C18 reversed phase and size-exclusion high-performance liquid chromatography (HPLC). The tube feet extract and the purified peptides (AST-I and AST-II) showed potent contractile activity on dorsal retractor muscle (DRM) of the starfish Asterina pectinifera and intestine (smooth muscle) of the panther puffer Takifugu pardalis. Treatment of the purified peptides with dithiothreitol (DTT) for 60 min at $37^{\circ}C$ significantly altered their retention times, suggesting that these compounds contained disulfide bonds. The molecular weights of AST-I and AST-II were determined to be 2064.2 Da and 6137.2 Da, respectively, by MALDI-TOF mass spectrometry.

• Journal of Korean Society of Water and Wastewater
• /
• v.22 no.1
• /
• pp.31-38
• /
• 2008

The primary objective of this study was to evaluate the variation of the molecular size distribution by granular activated carbon (GAC) adsorption. GAC adsorption was assessed by using the rapid small-scale column test (RSSCT) and high-performance size-exclusion chromatography (HPSEC) was used to analyze the molecular size distribution (MSD) in the effluent of GAC column. RSSCT study suggested that GAC adsorption exhibited excellent interrelationship between dissolved organic carbon (DOC) breakthrough and MSD as function of bed volumes passed. After GAC treatment, the nonadsorbable fraction which was about 25percents of influent DOC corresponded to the hydrophilic (HPI) natural organic carbon (NOM) of NOM fractions and was composed entirely of <300 molecular weight (MW) in the HPSEC at the initial stage of the RSSCT operation. The dominant MW fraction in the source water was 1,000~5,000daltons. At the bed volumes 2,500, MW <500 of GAC treated water was risen rather than it of source water. After the bed volumes 7,300 of operation, the MW 1,000~3,000 fraction was closed to about 80percents of DOC found in the GAC influent. The Number-average molecular weight (Mn) value determined using HPSEC for the effluent of GAC column was gently increased as DOC breakthrough progress. The quotient p(Mw/Mn) can be used to estimate the degree of polydispersity was shown greatest value for the GAC effluent at the initial stage of the RSSCT operation.

• Korean Journal of Food Science and Technology
• /
• v.31 no.2
• /
• pp.308-313
• /
• 1999

Total polar lipid produced from the soybean oil and lard by heating with different surface area at $185^{\circ}C$ were measured by silica gel column chromatography. Further, the polar lipid was fractionated by high performance size exclusion chromatography-evaporative light scattering detector (HPSEC-ELSD). The HPSEC system was composed of two GPC columns $(100\;{\AA}\;and\;500\;{\AA})$ and a THF mobile phase. With this system it was possible to fractionate into the free fatty acid, diglyceride, triglyceride monomer, triglyceride dimer and triglyceride polymers. The triglyceride monomer, triglyceride dimer and triglyceride polymers significantly increased as the heating time and surface area increased. But diglyceride and free fatty acid did not increased as the heating time and surface area increased. Triglyceride polymer (r>0.93), triglyceride dimer (r>0.97), triglyceride monomer (r>0.95) showed a high correlation with polar lipid content. On the other hand, diglyceride (r<0.68) and free fatty acid (r<0.76) were not significantly correlated with the polar lipid content. These results indicated that a major oxidative components formed during thermal oxidation were triglyceride polymers and triglyceride dimer and triglyceride monomer.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.38 no.5
• /
• pp.286-290
• /
• 2005

Oxytocin (OT)-related peptide, isotocin was purified from the brain extract of conger eel (Conger myriaster) using reverse-phase, ion-exchange and size exclusion high performance liquid chromatography (HPLC). The sequence of the peptide, with a molecular weight of 967.30 Da, was determined as Cys-Tyr-Ile-Ser-Asn­Cys-Pro-Ile-Gly-$NH_2$, where the Cys between 1st and 6th residues made an intramolecular disulfide bridge by the automated amino acid sequence analysis and MALDI-TOF mass spectrometry. The sequence was confirmed by identical elution with the purified and synthetic peptide using the HPLC system. As a result of homology investigation, the primary structure of this peptide was the same as that of OT -superfamily member, isotocin. The synthetic peptide showed a contractile activity at a minimal effective concentration of $10^{-7}M$ on the intestinal smooth muscle of goldfish (Carassius auratus).

• Journal of Microbiology and Biotechnology
• /
• v.17 no.9
• /
• pp.1513-1520
• /
• 2007

[ ${\beta}$ ]-1,3-Glucans enhance immune reactions such as antitumor, antibacterial, antiviral, anticoagulatory, and wound healing activities. ${\beta}$-1,3-Glucans have various functions depending on the molecular weight, degree of branching, conformation, water solubility, and intermolecular association. The molecular weight of the soluble glucan was about 15,000 as determined by a high-performance size exclusion chromatography. From the infrared (IR) and $^{13}C$ NMR analytical data, the purified soluble glucan was found to exclusively consist of ${\beta}$-D-glucopyranose with 1,3 linkage. We tested the immunestimulating activities of the soluble ${\beta}$-1,3-glucan extracted from Agrobacterium sp. R259 KCTC 1019 and confirmed the following activities. IFN-$_{\gamma}$ and each cytokines were induced in the spleens and thymus of mice treated with soluble ${\beta}$-1,3-glucan. Adjuvant effect was observed on antibody production. Nitric oxide was synthesized in monocytic cell lines treated with ${\beta}$-1,3-glucan. The cytotoxic and antitumor effects were observed on various cancer cell lines and ICR mice. These results strongly suggested that this soluble ${\beta}$-1,3-glucan could be a good candidate for an immune-modulating agent.

• Korean Journal of Food Science and Technology
• /
• v.30 no.3
• /
• pp.494-497
• /
• 1998

Deodorization of soybean oil was carried out at a temperature range of $220{\sim}280^{\circ}C$ for 1 or 2hrs. HPSEC(high performance size exclusion chromatography) method was used for the analysis of dimeric acids in deodorized soybean oil. Dimeric acid moieties were produced through the deodorization at $240{\sim}280^{\circ}C$ for 2 hrs. The amount of dimeric acids produced was found to be in the range of 0.36 to 3.39%. Dimeric acids were not detected under the deodorizing condition of $240^{\circ}C,\;2\;hrs\;or\;250^{\circ}C,\;1\;hr$. The soybean oil deodorized in these conditions had good quality by the color and viscosity tests. The best condition of minimizing the formation of dimeric acids in soybean oils was the deodorizing conditions of $240^{\circ}C,\;2\;hrs\;or\;250^{\circ}C,\;1hr$.

• Korean Journal of Food Science and Technology
• /
• v.26 no.1
• /
• pp.74-80
• /
• 1994

As a preliminary study about the reduction of the antigenicity of whey protein isolate(WPI) by treatment of chymotrypsin, trypsin, pancreatin, and protease from Aspergillus oryzae, the properties and antigenicities of whey protein hydrolysates(WPH) were investigated. When degrees of hydrolysis (DH) were measured by use of trinitrobenzensulfonic acid(TNBS), the DH of the WPH treated by pancreatin or protease from Aspergillus oryzae$(5.05{\sim}11.47)$ were much higher than those of the tryptic or chymotryptic WPH$(15.67{\sim}20.20)$. And the pretreatments of heat$(75^{\circ}C)$, 20 min and/or pepsin resulted in higher DH of WPH, generally. When the molecular distributions of the WPH were determined by high performance size exclusion chromatography(HPSEC), the ratios of polypeptides with molecular weight more than 10kDa ranged from 12% to 36%, and the average molecular weights and the average peptide lengths of the WPH were $4,252{\sim}9,132$ dalton and $38{\sim}83$ amino acids, respectively. And there was no bitter taste in all of the WPH. Results of SDS-PAGE showed that most of intact native proteins were eliminated by the enzymatic hydrolysis but there were a few bands of peptides larger than 14.2 kDa in some WPH. When antigenicity was assayed by competitive inhibition enzyme-linked immunosorbent assay(cELISA), monovalent antigenicity of WPH to rabbit anti-WPI antiserum were lowered to $10^{-1.7}-10^{-4.9}$ times and less by the enzymatic hydrolysis. And the pretreatments of heat and pepsin resulted in the lowest antigenicicy within a group of enzymatic hydrolysis, especially in case of the pancreatic hydrolysate(PDP) whose antigenicity was found almost to be removed.

• Korean Journal of Food Science and Technology
• /
• v.31 no.5
• /
• pp.1300-1307
• /
• 1999

Supercritical fluid extraction was applied to recycling triglyceride from used shortening. Used shortening and its fractions were analyzed with high performance size exclusion chromatography for their composition in triglycerides, polymer and low molecular weight compounds. Conjugated diene value and color of the fractions were also measured with a UV spectrophotometer and a colorimeter, respectively. Pressure and temperature ranges employed were $15{\sim}30$ MPa and $40{\sim}60^{\circ}C$, respectively. Concentration of fat in supercritical (SC) $CO_2$ ranged from $0.3\;X\;10^{-3}{\sim}7.4\;X10^{-3}(g\;fat/g\;CO_2)$. An exponential relation between concentration of fat in SC $CO_2$ and density was observed. Color of the extracts was light yellow which was very close to that of the fresh shortening. Low molecular weight compounds were preferentially concentrated in the initial fraction, while polymer was extracted in the final fraction. Conjugated diene value of the initial fractions was clearly lower than that of feed. It increased sharply as the polymer content in the fraction became significantly large.