• Clean Technology
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• v.28 no.1
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• pp.24-31
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• 2022

Petroleum-based plastics are used for various purposes and pose a significant threat to the earth's environment and ecosystem. Many efforts have been taken globally in different areas to find alternatives. As part of these efforts, this study manufactured alginate-based polyvinyl alcohol (PVA) blended films by casting from an aqueous solution prepared by mixing 10 wt% petroleum-based PVA with biodegradable, marine biomass-derived alginate. Glutaraldehyde was used as a cross-linking agent, and cardanol, an alkyl phenol-based bio-oil extracted from cashew nut shell, was added in the range of 0.1 to 2.0 wt% to grant antibacterial activity to the films. FTIR and TGA were performed to characterize the manufactured blended films, and the tensile strength, degree of swelling, and antibacterial activity were measured. Results obtained from the FTIR, TGA, and tensile strength test showed that alginate, the main component, was well distributed in the PVA by forming a matrix phase. The brittleness of alginate, a known weakness as a single component, and the low thermal durability of PVA were improved by cross-linking and hydrogen bonding of the functional groups between alginate and PVA. Addition of cardanol to the alginate-based PVA blend significantly improved the antibacterial activity against S. aureus and E. coli. The antibacterial performance was excellent with a death rate of 98% or higher for S. aureus and about 70% for E. coli at a contact time of 60 minutes. The optimal antibacterial activity of the alginate-PVA blended films was found with a cardanol content range between 0.1 to 0.5 wt%. These results show that cardanol-containing alginate-PVA blended films are suitable for use as various antibacterial materials, including as food packaging.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.723-730
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• 2016

In this study, we developed traditional liquor, Omegisul, with seaweeds to support the regional culture of Jeju Island in manufacturing traditional liquors. Seaweed extracts from Sargassum fulvellum and Hizikia fusiformis were added for manufacturing Omegisul at a final concentration of either 5 or 10% and fermented for 10 days. During fermentation, samples were collected to measure changes in quality of Omegisul including pH, acidity, alcohol content, chromaticity, total microbes, organic acid content, and antioxidant activity. Both pH and acidity of Omegisul were significantly altered in the early stages of fermentation. Alcohol contents increased over the fermentation period up to 9%. Regarding chromaticity of the product, L, a, and b values were highest in Omegisul with 10% Hizikia fusiformis. Both total plate count and lactic acid bacterial count tended to increase in the early stage of fermentation and decrease later, reaching their highest points in Omegisul with 10% Hizikia fusiformis at 10 days: $1.45{\times}10^8CFU/mL$ and $2.21{\times}10^8CFU/mL$, respectively (P<0.05). Among organic acids, lactic acid contents were significantly higher during fermentation with the highest concentration of 7.474 mg/mL in Omegisul containing 10% Sargassum fulvellum. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays showed that antioxidant activity of Omegisul was increased during fermentation period. Among the samples, Omegisul with 10% Sargassum fulvellum showed the highest antioxidant activities of 69.81% and 81.61% in DPPH and ABTS assays, respectively. Taken together, Omegisul with 10% Sargassum fulvellum showed better characteristics in terms of quality than the other groups and has potential as functional Omegisul.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1079-1084
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• 2004

The present study was conducted to compare antioxidant activity of green teas, fermented teas and other related common teas by examining radical scavenging activity using DPPH (2,2 diphenyl l-picryl hydrazyl). Scavenging activity ($SC_{50}$/) of epigallocatechin gallate (EGCG) for 0.1 mM DPPH radical was 5.5 $\mu$M or 4.2 mg/L by weight, then catechin, 14 $\mu$M or 2.5 mg/L and vitamin C, 22 $\mu$M or 3.9 mg/L, respectively. Kyokuro tea (okro) powder of 24.2 mg/L or green tea powder of 25.2 mg/L was used to reach $SC_{50}$/ for 0.1 mM DPPH. One serving of 2 g green tea provides antioxidant activity equivalent to 109∼147 mg EGCG, 145∼185 mg catechin or 131∼168 mg vitamin C. Teas from the first harvest had the highest radical scavenging activity when compared with later harvest green teas grown in the same region, but there is virtually no difference by the harvest time. A Chinese green tea, Dragon well had the highest antioxidant activity among other green teas tested providing antioxidant capacity equivalent to 168 mg EGCG or 188 mg vitamin C per 2 g serving, but partially fermented Chinese teas had much lower antioxidant activity than any green tea tested. Black tea which is fully fermented showed as strong antioxidant activity as green teas (76.3 mg vs 86.7∼67.6 mg per tea bag). One tea bag of green teas from market provided antioxidant capacity equivalent to 52∼86 mg EGCG, 70∼105 mg catechin or 63-96 mg vitamin C. Teas made of persimmon leaf, pine needle, mulberry leaf had comparatively low anti-oxidant activity equivalent to 2.5∼4.8 mg EGCG or 15∼21 mg vitamin C per teabag. The third brewed green tea still had enough antioxidant activity, while tea from tea bag brewed for 3 min or 5 min did not have any difference in their antioxidant activity. More systemic studies are needed to clarify the relationship between tea catechins and antioxidant capacity focusing on how growing, harvest time, fermentation and other processes can influence on this.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.48-59
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• 2018

This study was conducted to suggest the effective management and recycling processes of coffee waste, which can be easily obtained from coffee shops and coffee-related products industries. Prior to the fabrication of pellets, the potential of coffee waste as a raw material of pellet was investigated through the examination of its chemical compositions and fuel characteristics. Major gradient included in coffee waste was holocellulose, followed by fat/oil and protein. Coffee waste contained a small quantity of ash (0.7%), such as calcium, sodium, potassium and magnesium. Interestingly, coffee waste was easily dried probably due to its porous structure. Pellets fabricated with coffee waste and larch sawdust showed good fuel characteristics, such as moisture content, ash content, density and durability. The pellets exceed greatly the minimum requirements of $1^{st}$-grade wood pellet standard designated by National Institute of Forest Science (NIFOS). Particularly, the high calorific value of coffee waste showed the potential as a raw material of pellet. However, owing to high nitrogen and sulfur contents, coffee waste is like to be used as a raw material of wood pellet for combined heat and power plants equipped with a reduction system of $NO_x$ and $SO_x$ gases. On the other hand, 91 wt% larch sawdust and 9 wt% coffee waste are required to fabricate the $1^{st}$-grade wood pellets designated by NIFOS. Pellets fabricated with the conditions are estimated to have nitrogen content of 0.298% and sulfur content of 0.03%. Lastly, if amounts of coffee waste and sawdust in the production of wood pellets are adequately adjusted according to its purchasing price, the manufacturing cost of pellet can effectively be reduced. In addition, it is expected tp prepare the effective recycling process of waste and to relieve the environmental burden with the reduction of waste from the commercialization of coffee waste/larch pellets.

• Food Science of Animal Resources
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• v.28 no.3
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• pp.327-332
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• 2008

This study was conducted to evaluate the effects of dietary Bacillus subtilis on meat quality, growth performance and fecal malodor gas emission in finishing pigs. Thirty-six pigs (Landrace ${\times}$ Yorkshire ${\times}$ Duroc, $83.53{\pm}1.01\;kg$ average initial body weight) were used in a 35 d growth assay. Dietary treatments were 1) CON (basal diet), 2) B1 (basal diet + B. subtilis 0.1%) and 3) B2 (basal diet + B. subtilis 0.2%). The pigs were distributed into four pigs per pen with three replicate pens per treatments by completely randomized design. For the entire period, the final weight, ADO, ADFI and gain/feed were not significantly different among the treatments. There were no significant differences in meat quality (sensory evalution, meat color, TBARS, water holding capacity, drip loss, cooking loss and M. longissimus dorsi area) among the treatments. $H_2S$ was significantly decreased in B2 treatment compared to CON and B1 treatments (p<0.05). However, ammonia, mercaptans and acetic acid were not significantly different among the treatments. In conclusion, B. subtilis 0.2% treatments decreased fecal $H_2S$ gas emission in finishing pigs.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.595-604
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• 1992

Carbonate-type polyurethane resins containing anionic moieties were systhesized from NCO-terminated prepolymer method. Membranes were manufactured from the polymer solution and the separation of aqueous ethanol solution was investigated. To enhance the property of urethane resin, carbonate-type polyol(PTMCG) was used. ${\alpha}^{\prime},{\alpha}^{{\prime}{\prime}}$-dimethylolpropionic acid was used as a chain extender to increase the hydrophilicily of the urethane membrane. The ionization of the pendent carboxylic groups in urethane resin was carried out using trimthylamine. To confirm the formation of anionic groups in urethane resin, IR spectra of model compounds were compared with those of urethane resins. It was confirmed that the concentration of hard segment and hydrogen bond contributed to the property of the concentration of hard segment and hydrogen bond contributed to the property of urethane resin in which the mole ratio of chain extender and polyol was from 3:1 to urethane resin in which the mole ratio of chain extender and polyol was from 3:1 to 5:1. The carbonate-type polyurethane containing pendent carboxylic grop(PU) had Tg of around-$25^{\circ}C$ and Tm, $45^{\circ}C$ measured by DSC. Transition temperatures of one containing pendent anionic group(APU) prepared from the ionization of PU shifted to $8{\sim}10^{\circ}C$ lower temperature region than those of PU. Pervaporation membrane was prepared through the casting method. N, N-dimethylformamide (DMF) were used as a solvent and hexamethylene diisocyanate(HMDl) as a crosslinking agent. Swelling degree increased with ethanol concentration in mixure and the control of the swelling degree of the membrane could be achieved by crossliking. The results of pervaporation were as follows : separation factor, 2.3~9.8 ; flux, $27{\sim}79.5g/m^2hr$. Pervaporation separation capacity could be enhanced by reducing the molecular weight of polyol from 2,000 to 1,000.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.52-57
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• 2003

Nutritional compositions of the raw materials, such as well-milled rice, milled upland glutinous rice, milled barley, glutinous millet, SoRiTae, red beans and mung beans were analysed, and cooking characteristics and sensory attributes of mixed cereals were measured. Crude protein and crude fat in SoRiTae were 31.6% and 16.16%, respectively, and the highest among the raw materials. Crude ash was 3~11 times higher and crude fiber was 5~7 times higher in legumes than in grains. Iron content in SoRiTae was the highest as 7.8 mg/100 g, and calcium content was the highest as 71.0 mg/100 g in SoRiTae and mung beans. Phosphorus content was higher in glutinous millet and mung beans, and potassium content was greatly higher in legumes than in grains and the highest as 934 mg/100 g in red beans. Vitamin B$_1$ and B$_2$ contents were higher in legumes than in grains, and niacin content was the highest as 5.51 mg/100 g in mung beans and was 3.77 mg/100 g in glutinous millet. Water uptake of the raw materials increased greatly after 5 min of soaking in water and then stayed at the almost same level. Water uptake was the highest in SoRiTae and decreased in the order of milled barley, milled upland glutinous rice, glutinous millet and well-milled rice. Hardness was the lowest as 142.8 g/cm$^2$ in cooked SoRiTae, and the highest as 206.3 g/cm$^2$ in cooked milled barley compared with 169.4 g/cm$^2$ in cooked well-milled rice. Cooking time increased and hardness of cooked mixed cereals decreased with the increase of water added. Moisture content decreased, while crude protein, crude ash and crude fiber increased as the increase of mixing ratio of SoRiTae and red beans in mixed cereals. Lightness decreased, while red and blue color increased, and hardness increased with the increase of mixing ratio of SoRiTae and red beans. Sensory evaluation showed greater preference in terms of color, roasted nutty, sweet taste and overall acceptance in the cooked mixed cereals with 8 and 10% of SoRiTae and red beans.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.2
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• pp.121-128
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• 2008

As an aquatic ecotoxicity test method, a bioassay using the inhibition of sporualtion of the green macroalga, Ulva pertusa, has been developed. Optimal test conditions determined for photon irradiance, pH, salinity and temperature were $100\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, $7{\sim}9$, $25{\sim}35\;psu$ and $15{\sim}20^{\circ}C$, respectively. The validity of the test endpoint was evaluated by assessing the toxicity of four metals (Cd, Cu, Pb, Zn) and elutriates of sewage or waste sludge collected from 9 different locations. When the metals were assayed, the $EC_{50}$ values indicated the following toxicity rankings: Cu ($0.062\;mg{\cdot}L^{-1}$) > Cd ($0.208\;mg{\cdot}L^{-1}$) > Pb ($0.718\;mg{\cdot}L^{-1}$) > Zn ($0.776\;mg{\cdot}L^{-1}$). When compared with other commonly used bioassays of metal pollution listed on US ECOTOX database, the sporualtion test proved to be the most sensitive. Ulva sporulation was significantly inhibited in all elutriates with the greatest and least effects observed in elutriates of sludge from industrial waste ($EC_{50}=6.78%$) and filtration bed ($EC_{50}=15.0%$), respectively. The results of the Spearman rank correlation analysis for $EC_{50}$ data versus the concentrations of toxicants in the sludge presented a significant correlation between toxicity and four heavy metals(Cd, Cu, Pb, Zn). The method described here is sensitive to toxicants, simple to use, easy to interpret and economical. It is also easy to procure samples and maintain cultures. The present method would therefore probably make a useful assessment of aquatic toxicity of a wide range of toxicants. In addition, the genus Ulva has a wide geographical distribution and species have similar reproductive processes, so the test method would have a potential application worldwide.