• Korean Journal of Food Science and Technology
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• v.12 no.2
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• pp.82-87
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• 1980

The red color bleaching phenomena of red pepper powder by the exposure to sun light were studied on the various factors such as drying methods of pepper and the storage conditions of pepper powder, relative humidities, particle sizes, and the amounts and qualities of light. The surface color of red pepper was rapidly bleached by the successive daily exposures until the color retention value (capsanthin remained/original capsanthin content) reached to 0.5, while that of dark storge showed a negligible change. The color changes were related with the cumulative solar energy at various water activities $(a_w)$. As decreasing $a_w$ below 0.5, the bleaching reaction was highly accelerated, and thereafter was slowly progressed. Sun lights transmitted by red-, yellow- and blue-gelatin filters, respectivly, bleached in different degrees and at the shorter wavelength light, the more color bleaching occurred. From this fact a red colored package film could be effectivly used for the color preservation purpose in the red pepper storage.

• Journal of Digital Convergence
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• v.17 no.1
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• pp.357-364
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• 2019

This study comparatively analyzed hair damage by hair bleach particles and identified three different bleach particle sizes using a scanning electron microscope (SEM). The powdered bleaching agents made of ammonium persulfate (APS) and potassium persulfate had particle sizes of $131{\mu}m$, $72{\mu}m$ and $48.8{\mu}m$. According to a hair damage test, cuticle lift-up or peeling hardly occurred when small bleach particles were used. In terms of hair color, the hair bleached with larger bleach particles was the darkest, while the hair bleached with small bleach particles was the brightest. The results found that for bleaching agents that are more effective in easing hair damage, those with little particles should be used. In addition, it appears that the selection of particles depending on the degree of hair bleaching would enhance bleaching effects and reduce hair damage. The above process is a way to get great results in selecting a bleaching agent. It is anticipated that hair damage could be reduced during hair bleaching based on the above results.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.560-567
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• 2016

Acid-activated clays (SUPER-DC, DC-A3, and P1) are used for the bleaching of cold-pressed rapeseed oil. In this study we tested the bleaching performance of cold-pressed rapeseed oil according to the different reaction time (20, 40, 60, 80 min) and temperature (40, 80, $120^{\circ}C$). Oil color (lightness, redness, yellowness), pigments (chlorophyll A and carotenoid content) and quality properties (fatty acid composition, tocopherols (${\alpha}$, ${\beta}$, ${\gamma}$, ${\delta}$), and plant sterols (${\beta}$-sitosterol, campesterol, stigmasterol) content) were analyzed. The results showed that bleaching of cold-pressed rapeseed oil with 2% acid-activated clays at $40^{\circ}C$ for 20 min, brightness (L) increased, but redness (a) and yellowness (b) decreased. Bleaching of cold-pressed rapeseed oil with 2% DC-SUPER at $40^{\circ}C$ removed chlorophyll A and carotenoids pigments significantly. In addition, about 50% of total tocopherol content in cold-pressed rapeseed oil was reduced by bleaching. Originally total tocopherol content was 46.62mg/100g in cold-pressed rapeseed oil. But after bleaching, total tocopherol content was 12.67mg/100g (20 min bleaching), 15.31mg/100g (40 min bleaching), and 13.56mg/100g (60 min bleaching). However plant sterols content in cold-pressed rapeseed oil remained unchanged by bleaching. Overall, acid-activated clays were useful for the bleaching of pigmented rapeseed oil.

• Korean Journal of Microbiology
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• v.42 no.1
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• pp.34-39
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• 2006

Wood-rot fungi produce extracellular lignin-degrading enzymes, the best known of which are lignin peroxidase, Mn-peroxidase and laccase. In this experiment, some of them produced all of three enzymes. Many other wood-rot fungi produced one or two of those enzymes with various combinations. In this experiment, we tried to clarify the relationship between the pattern of enzyme production and degradative activity of several dye compounds. From the 36 strains of 23 species of wood-rot fungi, Mn-peroxidase activity was found in 30 strains of the fungi tested, whereas the activity of lignin peroxidase and laccase was detected in 11 strains and 12 strains of species, repectively, in Kirks low nitrogen media. In relation to the activity of lignin degrading enzymes and degradation of dye compounds, the white-rot fungi with three kinds of enzymes tested showed the best dye decolorizers. The fungi with Mn-peroxidase activity only decolorized poly R-478 and remazol brilliant blue R dye in proportion to the enzyme activity, while methylene blue, bromophenol blue and congo red dye were degraded in regardless of enzyme activity. Those dyes were degraded in relation to the growth rate of mycelium. Brown-rot fungi did not degrade all the dye compounds except bromophenol blue, in spite of moderate growth rate.

• The Korean Journal of Mycology
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• v.40 no.2
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• pp.98-103
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• 2012

This study has been conducted to screen the decolorization of 4 aromatic synthetic dyes and production of ligninolytic enzymes by 4 white rot fungi such as Bjerkanderia adusta, Cerrena unicolor, Pleurotus pulmonarius and Abortiporus biennis. It was found that B. adusta, C. unicolor, and P. pulmonarius have the ability to efficiently decolorize congo red and moderately decolorized amaranth and orange G in solid and liquid culture media. However, the decolorization rate of 4 synthetic dyes by A. biennis was relatively low. The decolorization of congo red, amaranth, orange G were related to the growth rate of the fungal mycelia in the solid medium. But, the all fungi tested did not efficiently decolorize methylene blue in the liquid culture media. To investigate the production of ligninolytic enzymes in media containing aromatic compounds, fungi were cultured in 1% naphthalene supplemented potato dextrose broth medium. All fungi tested had the capability to produce laccase, lignin peroxidase and manganese peroxidase, and B. adusta was the best ligninolytic enzymes producing white rot fungus among other fungi tested.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.463-470
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• 2020

The JS18 strain was isolated from an old tree forest and produced extracellular enzymes that decolorize synthetic melanin. Phylogenetic analysis, based on the internal transcribed spacer (ITS) sequence, indicate that JS18 belongs to the Trametes velutina species. JS18 demonstrated laccase activity but no manganese peroxidase or lignin peroxidase activity. Batch culture indicated that the melanin decolorization activity of JS18 strain originated from the laccase. Syringic acid and CuSO4 induced maximum laccase production, yielding 98 U/ml laccase activity after cultivation for 7 days at 25℃. T. velutina secretes an extracellular laccase in GYP medium, and this enzyme was purified using (NH4)2SO4 precipitation, Hi-trap Q Sepharose columns and gel filtration. The molecular weight of the purified enzyme was estimated to be 67 kDa using sodium dodecyl sulfate polyacrylamide gel electrophoresis. This enzyme produced 80% of its melanin decolorization activity within the first 24 h of evaluation in the presence of 1-hydroxybenzotriazole (HBT), while only about 4% of the melanin was decolorized in the absence of the mediator. The greatest decolorization was observed at 1.5 mM/l HBT, which decolorized 81% of the melanin within the first 24 h. The optimum pH and temperature for this decolorization were found to be 5.0 and 37℃, respectively. Our results suggest the possibility of applying HBT induced T. velutina JS18 laccase-catalyzed melanin decolorization.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.79-82
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• 2017

An inky cap, Coprinus comatus synthesizes and secretes a laccase in the liquid yeast extract peptone dextrose medium. We have successfully purified the enzyme through the ion-exchange chromatography and the preparative gel electrophoresis. The estimated molecular weight was 67 kDa by the SDS-PAGE analysis. Optimum pH was pH 4.3 and optimum temperature was $25^{\circ}C$. The Km value was 0.45 mM and the Vmax was 0.0132 OD/min/unit for o-tolidine. Purified laccase showed 49.3% decolorizing activity against remazol brilliant blue R (RBBR) and 41.6% decolorizing activity against Poly R-478 after 12 h incubation.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.792-798
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• 2000

The objectives of this study were to reduce the characteristic dark color of Korean wheat flour noodles. Several additives were tested to reduce dark color of wheat flour dough and 2% ascorbic acid and 0.05% cysteine were selected as additives to Korean wheat flour noodle. Comparative study was performed between commercial imported wheat flour noodle and Korean wheat noodle with two additives to investigate the color, mechanical and sensory properties of noodles. Addition of 2% ascorbic acid increased the brightness of raw and dried Korean wheat flour noodles and 0.05% cysteine was the most effective in improving the brightness for cooked wheat flour noodles. Mechanical properties of cooked Korean wheat flour noodles with 2% ascorbic acid and 0.05% cysteine were similar to that of the imported wheat flour noodles. However, sensory evaluation test showed Korean wheat flour noodles with 2% ascorbic acid had the darkest yellowish-red color, the strongest aftertaste and the lowest overall quality. Therefore, the addition of cysteine was the most effective in mechanical and sensory attributes as well as discoloration of cooked wheat flour noodles.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.584-590
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• 2017

Effects of bleaching and deodorization on the quality of imported palm and canola oils were evaluated. Imported palm oil and deacidified canola oil were bleached with acid clay, followed by deodorization. Oxidation-related quality was evaluated by determining fatty acid composition by GC, acid and peroxide values, induction period by Rancimat, and off-flavor compounds by GC-MS. Tocopherols and benzo(a)pyrene were analyzed by HPLC. Acid and peroxide values were decreased by bleaching and deodorization, and tocopherol content was decreased to 60-70% (p<0.05). Aldehydes were major off-flavor compound class of imported oils, most of which were removed after deodorization. No significant change was observed in benzo(a)pyrene content (${\sim}0.4{\mu}g/kg$) of both oils by bleaching and deodorization (p>0.05). The oxidation-related quality of palm and canola oils was more improved after industrial bleaching than by deodorization. These results suggest that a careful control of bleaching during domestic refining can improve the quality of palm and canola oils.

• Analytical Science and Technology
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• v.13 no.3
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• pp.351-356
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• 2000

The decolorization of wastewater and the collecting conditions of final sludge from hanji production were investigated. Black wastewater (50 mL) from the process cooking with NaOH could be effectively decolorized by 2.0 g of $Ca(OCl)_2$ So, if excess bleach $Ca(OCl)_2$ used in bleaching process were recycled, the decolorization of wastewater by adding less $Ca(OCl)_2$ would be successfully realized. However, the decolorization by electrolyzed oxidation was ineffective. The final sludge could be effectively collected by polymer coagulator, but the addition of $Al_2(SO_4)_3$ was required, and the pure fibrous sludge could not be collected. Therefore, surfactants such as triethanolamine and Triton X-100 were used instead of polymer coagulator. The collecting yield was obtained about 85% as good as those by polymer coagulator. When mixed surfactants were used in collecting the final sludge, $Al_2(SO_4)_3$ was not required. In addition, as the pure fibrous sludge could be collected, the effective recycling of sludges would be done.