• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 1991.11a
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• pp.186-187
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• 1991

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.440-446
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• 1989

Penicillium sp. CB-20 was selected for its strong polygalacturonase activity among various strains of molds found in soil. It was found that the production of polygalacturonase reached to maximum when on the wheat bran medium containing pectin as carbon source, the strain was cultured for 60 hours at 3$0^{\circ}C$. The enzyme was purified to 29.21 food by ammonium sulfate treatment, Sephadex G-25, G-15, G-150 gel filtration, DEAE-cellulose and DEAE-Sephadex A-50 ion-exchange chromatography. Yield of the enzyme purification was 2.31 %. When the purified enzyme was applied to sodium dodecyl sulfate polyacrylamide gel electrophoresis, the molecular weight was estimated 21, 000. The amino acid composition indicated relatively high contents of gultamic acid, glycine and histidine.

• Applied Biological Chemistry
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• v.30 no.4
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• pp.305-310
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• 1987

The enzymatic properties of ${\beta}-amylase$ from soybean and sweet potato were compared. The sweet potato enzyme consists of four identical subsunits whereas soybean enzyme has no subunit $structure^{12,\;15)}$. In the denatured state, both enzymes exhibited the same molecular weight on SDS-gel electrophoresis and on gel-filtration analysis. The spectra of circular dichroism revealed that both enzyme have almost same secondary structure but the environment of aromatic side chains are different. The chemical cleavage of soybean and sweet potato ${\beta}-amylases$ at cysteine residues and methionine residues demonstrated the homology of amino acid sequence between the enzymes. The similarity between soybean and sweet potato ${\beta}-amylase$ was also revealed by immunological method. The antibody for soybean enzyme inhibited the activity of sweet potato enzyme but it did not inhibit the activity of wheat, barley and Japanese-raddish ${\beta}-amylases$.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.379-386
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• 1998

Deterioration of food is in general caused by the presence of microorganisms and chemical compounds of food itself. There exists antimicrobial compound in the food, however, addition of food antiseptics, additives, or physico-chemical processing is a common practice. The safety of artificial chemical antiseptics became a serious public concern, therefore, new natural antiseptic compounds are in need to be developed. We have isolated a new natural antifungal protein (KBS-B2) from Astragal seed through ammonium sulfate precipitation and column chromatography using FPLC Mono-S and Superose 12HR. The purified protein inhibited growth of Candida albicans, and spore germination of food spoiling fungi such as Aspergillus ochraceus, Penicillium expensum, P. digitatum and Botrytis cineria. Antifungal effect of the KBS-B2 protein could be directly assayed by bioautography overlaying the fungal spores on the electrophoresed acrylamide gel. The comparison of N-terminal amino acid sequences of the KBS-B2 with known antifungal protein revealed that had 50% homology to thaumatin and zeamatin like proteins.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.649-654
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• 1993

We investigated the texture of the sweet potato starch gels treated with maltogenic amylase. Effects of branched gluco-oligosaccharides and acorn starch on the texture of the sweet potato starch gel were also investigated. Hardness and cohesiveness of gels were measured by using Instron and sensory evaluation on the gel properties was performed. From the results of the instrumental analysis, it was found that the overall textural properties as Mook could be improved by adding branched glucooligosaccharides, maltogenic amylase or acorn starch to the sweet potato starch gel. As a result, there was a decrease in the cohesiveness of gels while the hardness of gels increased. The sensory evaluation study indicated that the sweet potato starch gels treated with 0.02% maltogenic amylase, or added with 12.5% branched gluco-oligosaccharides, or mixed with 50% acorn starch had preferable quality as Mook.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.627-634
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• 2012

This study was carried out to investigate the physical and thermal properties of ${\kappa}$-carrageenan (${\kappa}$-car) gel added whey protein isolate (WPI) as a cryoprotectant. The concentration of ${\kappa}$-carrageenan was fixed at 0.2 wt%. The mean ice crystal size of the WPI/${\kappa}$-car was decreased according to increasing whey protein isolate concentration. The temperature of gel-sol (Tg-s) and sol-gel (Ts-g) transition of WPI/${\kappa}$-car maxtrix was represented in the order of 3.0, 0.2, 5.0 and 1.0 wt%. In addition, the transition temperature of gel-sol of WPI in sucrose solution were showed in order of 1.0, 5.0, 0.2 and 3.0 wt% depending on whey protein isolate concentration. The shape of ice crystal was divided largely into two types, round and rectangular form. 1.0 wt% WPI/${\kappa}$-car matrix at pH 7 and 9 showed minute and rectangular formation of ice crystals and whey protein isolate in sucrose solution at a concentration of 1.0 wt% WPI/${\kappa}$-car matrix at pH 3 and 5 showed relatively large size and round ice crystals. The ice recrystallization characteristics and cryprotective effect of ${\kappa}$-carrageenan changed through the addition of different concentrations of whey protein isolate. It seems that the conformational changes induced interactions between whey protein isolate and ${\kappa}$-carrageenan affected ice recrystallization.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.600-603
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• 1996

The methanol extract of Aralia elata bark showed antimicrobial activities against bacteria, yeast and fungi. The active components were successively purified with solvent fractionation, silica gel adsorption column chromatography, Sephadex LH-20 column chromatography, silica gel partition column chromatography and HPLC. The active substances were separated with HPLC where 1% acetic acid-MeOH (60 : 40, v/v) was used as mobile phase. The isolated active substance ($t_r$ 17.1 min) was identified as trans-3,4-dihydroxycinnamic acid by $MS,\;^1H-NMR\;and\;^13C-NMR$.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.493-497
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• 2002

The polyphenol compounds of Korea ginseng radix were extracted with 60% acetone for 4 days at room temperature and purified using Sephadex LH-20 column chromatography, MCI gel column chromatography, Bondapak $C_{18}$, column chromatography, TLC and HPLC. As a result in three compounds were isolated from Korean ginseng. In the inhibitory activities of angiotensin converting enzyme, compound Ⅱ showed the highest value of 31.86% inhibition at 157 ppm. Compound I showed 19.4% inhibition at 157 ppm. In the inhibitory activities of xanthine oxidase, compound I, II showed complete inhibition at 666 ppm but compound III didn't have inhibitory activity. In the inhibitory activities of tyrosninase, compound III showed 6.1% inhibition at 300 ppm and 28.6% at 400 ppm.

• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.21-28
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• 2004

We purified and characterized a crude polysaccharide from Spirodela polyrhiza with anti-complement activities. The crude polysaccharide fraction (SP-0) which had potential anti-complement activity was extracted in hot water for 4 hrs at 10$0^{\circ}C$. The ethanol-precipitate, the crude polysaccharide traction (SP-1), showed a potent anti-complement activity. Further purification of the crude polysaccharide (SP-1) was carried out by cetavlon, ion exchange chromatography and gel column chromatography. Among cetavlon fractions, SP-4 showed the most potent anti-complement activity. When 100 $\mu\textrm{g}$/mL of SP-4 was incubated with an equal volume of normal human serum (NHS), the TCH$_{50}$ was reduced by about 78%. When the SP-4 fraction was further purified by DEAE-Sepharose (Cl$^{[-10]}$ ), the SP-4IIa, SP-4IIb and SP-4IIc, absorbed fractions, were almost the same as the anti-complement activities of SP-4. SP-4IIc, having the greatest potential activation and the highest yield by ion exchange chromatography, was further purified by gel column chromatography on a Sepharose CL-6B column. Four polysaccharide fractions of SP-4IIc-1, SP-4IIc-2, SP-4IIc-3 and SP-4IIc-4 were obtained, consisting mainly of arabinose, rhamnose, galactose and glucose, with approximate molecular weights of about 305,000, 132,000, 64,000 and 12,000, respectively. Among these subfractions, SP-4IIc-1 had the most potent anti-complement activity. When the SP-4IIc-1 aggregate was applied to a gel column chromatography in 10 mM and 50 mM NaCl solution, the position of the peak fractions shifted to a low molecular weight region, and the molecular weight of SP-4IIc-1 decreased with increased NaCl concentration in the gel column chromatography. It was found that the self-aggregation formed spontaneously in void volume by gel column chromatography using Sepharose CL-6B in water and the self-aggregation significantly affected the anti-complement function.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.590-598
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• 2009

The aim of this study was to model and optimize the calcium alginate (CA) and microbial transglutaminase (TG) systems to form a cold-set myofibrillar protein (MP) gel containing 0.1 M or 0.3 M NaCl using a response surface methodology. The gel strengths of cold-set and heat-induced MP gels, and cooking yields were measured. All measured parameters showed determination coefficients ($R^2$) above 0.7 without a lack-of-fit. The CA system had the best results with component ratios of 1.0:0.3:1.0 corresponding to sodium alginate, calcium carbonate and glucono-$\delta$-lactone, respectively, and was favourable at 0.1 M NaCl. In contrast, the TG system only had an effect on cold-set MP gelation at 0.3 M salt, and the optimal ratio of TG to sodium caseinate was 0.6:0.5. By combining the two systems at 0.3 M NaCl, an acceptable cold-set MP gel with an improved texture and high cooking yield could be formed. Therefore, these results indicated that the functionality of the cold-set MP gel could be enhanced by combining these two optimized gelling system.