• Journal of Life Science
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• v.31 no.1
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• pp.100-108
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• 2021

In the oral cavity, there are hundreds of microbial species that exist as planktonic cells or are incorporated into biofilms. The accumulation and proliferation of pathogenic bacteria in the oral biofilm can lead to caries and periodontitis, which are typical oral diseases. The oral bacteria in the biofilm not only can resist environmental stress inside the oral cavity, but also have a 1,000 times higher resistance to antibiotics than planktonic cells by genes exchange through the interaction between cells in the oral biofilm. Therefore, if the formation of oral biofilm is suppressed or removed, oral diseases caused by bacterial infection can be more effectively prevented or treated. In particular, since oral biofilms have the characteristic of forming a biofilm by gathering several bacteria, quorum sensing, a signaling system between cells, can be a target for controlling the oral biofilm. In addition, a method of inhibiting biofilm formation by using arginine, an alkali-producing substrate of oral bacteria, is used to convert the distribution of oral microorganisms into an environment similar to that of healthy teeth or inhibit the secretion of glucosyltransferase by S. mutans to inhibit the formation of non-soluble glucans. It can be a target to control oral biofilm. This method of inhibiting or removing the oral biofilm formation rather than inducing the death of pathogenic bacteria in the oral cavity will be a new strategy that can selectively prevent or therapeutic avenues for oral diseases including dental caries.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.524-530
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• 1993

The experiment was carried out to investigate the changes in physicochemical properties of milled rice harvested in different year and stored for four to sixty four months. The fat acidity of milled rice increased sharply from four to sixteen months storage, and after then it was increased slowly to sixty four months. Amylose, magnesium, potassium content, and K/Mg ratio of milled rice were not changed by storage duration. Water absorption rates of milled rice at 21$^{\circ}C$ and 77$^{\circ}C$, and alkali digestion value were increased by longer storage duration. Difference of water absorption rate between rice samples was greater during initial forty minutes after soaking at 21$^{\circ}C$ and with longer the soaking time at 77$^{\circ}C$. Shorter gel length of rice flour was found with prolonged storage duration, while peak, minimum, cool, breakdown and setback viscosity of gelatinized rice flour on amylograph were increased along with increasing the storage duration. The volume expansion rate during cooking and degree of iodine coloration of cooking water were higher in the longer stored rice compared with shorter one, and the amount of soluble solid in cooking water was significantly decreased in rice stored longer period.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.9
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• pp.1154-1161
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• 2008

The purpose of this study is to determine the possibility of using Sophorae fructus as natural health food source. To accomplish this purpose, the contents of general and antioxidative nutrients of Sophora fructus were measured. The contents of carbohydrate, crude protein, crude lipid and ash are 75.9%, 16.4%, 2.41%, and 5.2%, respectively, while the calories of Sophora fructus was 337.3 kcal. Total dietary fiber was 15.07% of total carbohydrates. The percentages of water soluble dietary fiber to insoluble dietary fiber were 1.09% and 10.36%, respectively. The protein was composed of a total of 18 different kinds of amino acids. The contents of essential and non-essential amino acids were 2,310.91 mg and 5,218.52 mg. The K was the largest mineral followed by Ca, P and Mg, which means Sophorae fructus is alkali material. The contents of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids were 24.94%, 32.40%, and 32.86%, respectively. Therefore, the amount of the total unsaturated fatty acid was higher than that of any other plant. The content of vitamin C in Sophorae fructus was higher than that of any other plant, which suggests that it could increase blood elasticity. The content of rutin, which is responsible for capillary vessel permeability, was 1.78%. The contents of water soluble antioxidative materials in 1 mL of water-extracted Sophorae fructus were $4.95\;{\mu}g$ which is comparable to 1,560.96 mmol of vitamin C in antioxidant effect. The general nutrients and other antioxidatant bioactive materials in Sophorae fructus were also potential materials for good health food. It is expected that a follow up study on Sophorae fructus through developing processed food and evaluation of their functional properties would provide useful information as a source of medicinal foods.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.20-27
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• 1983

A series of laboratory experiment was conducted to find out the chemical composition, characterization of humic substances by physical and chemical methods and reaction of Na-pyrophosphate, $Ca(OH)_2$ and rice straw with albumin on the degradation of soil organic matter in the volcanic ask soils of the Jeju Island. Results obtained were summarized as follows: 1. The contents of organic matter, available silicon, active iron and aluminum concentration in volcanic ash the soils were remarkably higher but available phosphorous was comparatively lower than the mineral soils. In volcanic ash soil, the contents of potassium, calcium and magnessium were higher in upland soil than that of forest soil. The ratios of active $Al^{{+}{+}{+}}/Fe^{{+}{+}}$, C/P and $K/Ca^+$ Mg were apparently high in volcanic ash soils while that of $SiO_2$/O.M. was high in mineral soil. 2. The carbon/nitrogen ratio in humin, humic acid content in organic matter, and carbon contents of humin in total carbon of soil organic matter were apparently higher in the volcanic ash soils than in the mineral soils, The total nitrogen and fractions of acid or alkali soluble nitrogen were remarkably high in volcanic ash soils while mineralizable nitrogen ($NH_4$-N and $NO_3$) contents were high in mineral soils. 3. The values of K600, RF and log K were also higher in volcanic ash soils than those in mineral soils, and the absorbance in the visible range were high and color was dark in the soil of which humification was progressed Extracted humic acid from volcanic ash soil was less reactive to the oxidizing chemical reagent and was persistance to the acid or alkali hydrolysises. 4. The major oxygen-containing functional groups in humic substances of volcanic ash soils were phenolic-OH alcoholic-OH and carboxyl groups while those in mineral soil were methoxyl and carbonyl groups. 5. Absorption spectra of alkaline solution of humic acid ranged from 200 nm to maxima 500 nm. Visible spectra peaks of from humic substances in the visible region were recognized at 350, 420, 450 and 480 nm. Only one single absorbance peak was observed in the visible region at 362 nm for Heugag series and two absorbance Peak were also at 360 nm and 390 nm for Yeungrag series. 6. Evolution of carbon as $Co_2$ was increased with addition of Na-pyrophosphate in Namweon and Heugag series, and "priming effects" took place on the soil organic matter decomposition by addition of rice straw with albumin in Ido series.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.3
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• pp.133-141
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• 2007

There are produced more than 600,000 tons of seaweeds every year along the coast of the Korea. Jeonnam province, south-west coast area, of Korea is producing 93% of total amounts of seaweeds. The laver, sea mustard, and tangleweed maintain stability in the output and has been exported as a simple product processing through drying or salting. It was evaluated the low value-added products and limited the expansion for the consumption of seaweeds. The seaweeds contains 40-60% carbohydrate and structurally different compared with land plant. The dietary fiber from seaweeds has been known the function of facilitating the bowl movement, excretion the heavy metal in the body, lowering the blood cholesterol level, anti-coagulant of blood, and anticancer. Especially, brown algae including sea mustard, seaweed fusiforme, and tangleweed contains alginic acid, laminarin, mannitol, fucoidan which are lowering the blood cholesterol level, lowering blood pressure, and fusion of blood clot. Agar-agar, carrageenan, and porphyran compound in red algae are known to antimutagenicity and anticoagulant function. In spite of potential of seaweed as a main bio-resource, there are lack of research to facilitate the consumption with its functional properties and consumers are unsatisfied with simple processing products. Also, the seaweed by-product dump into the sea and cause pollution of the seawater. Therefore, there are needed the scheme to promote the consumption of seaweeds. The development of value-added products, finding functional properties from seaweeds, development the functional feed for animal using seaweed by-products, and utilization of unused algae for food or other industrial uses will increase fisherman's income as well as serve as an aid for the people health due to its functional properties. Using by-product of seaweed and unexploited seaweed are needed to development of bio-degradable food packaging material and functional feed for animal.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.1949-1957
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• 2013

The contents of ${\beta}$-carotene and retinol in processed and restaurant foods, such as Korean noodles, mandus, rice cakes and bread products, were quantified by high-performance liquid chromatography (HPLC) with UV/visible and fluorescence detector, respectively. Samples were collected from different local areas (i.e. Gangwon-do, Gyeonggi-do, Gyeongsang-do, Seoul, Jeolla-do, and Chungcheong-do). After homogenization, samples were hydrolyzed by direct alkali saponification; thereafter, fat-soluble components were extracted by a mixture of n-hexane/ethylacetate (85:15, v/v), containing 0.01% butylated hydroxytoluene (BHT). ${\beta}$-carotene and retinol contents in infant formula used as an in-house material for the analytical quality control. Among 14 Korean noodles, high contents of ${\beta}$-carotene were found in Bibim-Guksu (average 442.43 ${\mu}g/100g$) and Jjolmyeon (average 301.39 ${\mu}g/100g$). In 4 Korean mandus, the highest contents of ${\beta}$-carotene was determined in Kimchi-mandu (average 197.64 ${\mu}g/100g$), resulting in 33.3 RE of the converted vitamin A. Among 12 Korean rice cakes, Maeun-Tteokbokki and Modm-Chaltteok contained relatively high content of ${\beta}$-carotene with 205.11 and 41.33 ${\mu}g/100g$, respectively, while retinol was detected only in Maeun- Tteokbokki (1.65~10.45 ${\mu}g/100g$). In addition, among 8 bread products, 77.3 RE of pastry, 51.2 RE of buttercream- bread, and 41.4 RE of morning roll were found as the contents of the converted vitamin A.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.12
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• pp.1337-1346
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• 2006

Soil humin is the insoluble fraction of humic materials and play an important roles in the irreversible sorption of hydrophobic organic contaminants onto soil particles. However, there have been limited knowledge about the sorption and chemical properties of humin due to the difficulties in its separation from the inorganic matrix(mainly clays and oxides). In this study, de-ashed soil humins($Hu_1-Hu_6$) were isolated from a soil residues(Crude Hu) after removing alkali-soluble organic fractions followed by consecutive dissolution of the mineral matrix with 2%-HF for 2 hr. The humin samples were characterized by elemental analysis and $^{13}C$ NMR spectroscopic method and their sorption-desorption behavior for 1-naphthol were investigated from aqueous solution. The results were compared one another and that with peat humin. $^{13}C$ NMR spectra features indicate that the soil humin molecules are mainly made up of aliphatic carbons(>80% in total carbon) including carbohydrate, methylene chain. Freundlich sorption parameter, n was increased from 0.538 to 0.697 and organic carbon-normalized sorption coefficient(log $K_{OC}$) values also increased from 2.43 to 2.74 as inorganic matrix of the soil humin removed by HF de-ashing. The results suggest that inorganic phase in humin plays an important, indirect role in 1-naphthol sorption and the effects on the sorption non-linearity and intensity are analyzed by comparison between the results of soil humin and peat humin. Sorption-desorption hysteresis were also observed in all the humin samples and hysteresis index(HI) at low solute concentration($C_e$=0.1 mg/L) are in order of Peat humin(2.67)>De-ashed humin(0.74)>Crude Hu(0.59).

• Applied Biological Chemistry
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• v.23 no.3
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• pp.157-165
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• 1980

Kojis were prepared from the different starch raw materials such as glutinous rice, barley rice, wheat flour and sweet potato, and were tested in an effort to reduce production cost and to improve quality of Kochuzang(red pepper paste). During the starting period of Koji preparation, there were less significant changes in pH; however, pH decreased somehow in the case of sweet potato, whereas it increased for the other Kojis. In general, the highest acidity was obtained after 72 hours of Koji preparation. Total nitrogen, soluble nitrogen and amino-nitrogen content increased in order of wheat flour, barley rice, and glutinous rice; Kojis they were markedly produced between 72 and 96 hours of Koji preparation. The maximum amount of reducing sugar was observed between 48 and 72 hours of Koji preparation during this period the reducing sugar content varied widely depending on starch source. Sweet potato Koji produced the highest level of ethyl alcohol content after 72 hours of Koji preparation; for the other Koji the same trends were observed after 24 hours. The starch liquefying activities have reached the highest level after 96 hours and for glutinous rice and barley rice; however, they kept on increasing until 120 hours for wheat flour and sweet potato. Koji Starch liquefying and saccharogenic amylase activities tended to increase in order of sweet potato, glutinous rice, barley rice and wheat flour. Kojis Various protease activities were measu-red during the Koji preparation, and they increased in order of alkali, neutral and acidic protease.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.529-537
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• 1985

The present study was carried out to investigate the effect of the partial freezing as a means of keeping freshness of mullet (Mugil cephlus). Living samples were killed and stored by icing, partial freezing at $-3^{\circ}C$ and freezing at $-30^{\circ}C$, respectively, Changes in the freshness of the mullet muscle and the phys cal properties of its meat paste product were examined during storage. The results obtained are summarized as follows: The period that k value reached to $20\%$ during storage was the longest in the frozen storage, followed by the partial frozen storage and the ice storage, which was 4 days in the mullet muscle stored by partial freezing. In the case of VBN content, it was below 20 mg/100g in the mullet muscle stored by icing and partial freezing. The oxidation of lipids in the mullet muscle was greater in the ice storage than in the partial frozen storage. The myofibrillar protein of the mullet muscle was appeared to decrease during storage, which the decreasing ratios during storage for 9 days were below $3\%$ in the frozen storage, $17\%$ in the ice storage and $10\%$ in the partial frozen storage. While, the alkali-soluble protein showed to increase and in non-protein nitrgenous compounds, sarcoplasmic protein and stroma was not a great change during storage. The decrease of gel strength, folding strength and texture of meat paste products prepared under different storage conditions was the greatest in the ice storage, the next in the partial frozen storage and such changes in the frozen storage were not so much. In gel strength of the product prepared with sample fishes stored for 10 days, the gel strength in the ice storage, partial frozen storage and frozen storage was about $30\%,\;60\%\;and\;97\%$ of the control. respectively. The expressible drip of the products increased with storage time of raw fishes, which that of the products prepared with sample fishes stored for 15 days was about 2.1 times in the ics storage, about 1.5 times in the partial frozen storage and about 1.1 times in frozen storage as much as that of the control, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.1
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• pp.27-35
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• 1986

In succession to the previous paper, the present study was directed to investigate the effect of keeping freshness of conger eel (Astroconger myriaster) and yellowtail (Seriola quinqueradiata) by partial freezing, and the changes in the physical properties of fish meat paste product prepared with the muscle of conger eel during storage were also examined. The results obtained are summarized as follows: The period of keeping freshness (days in which k value reaches $20\%$) of conger eel and yellowtail by partial freezing was 10 days and 6 days, respectively. VBN content in the conger eel muscle showed 39.5 mg/100g by icing for 15 days, and did not show a great change by partial freezing and freezing, while that of yellowtail muscle reached at 32 mg/100g by icing, 20 mg/100g by partial freezing and 18 mg/100g by freezing for 15 days. The lipids extracted from the muscles of both fishes by icing were remarkably oxidized than those by partial freezing. The myofibrillar protein in the conger eel muscle during storage for 9 days decreased $3\%,\;10%\;and\;11\%$ by icing, partial freezing and freezing, respectively, and that of yellowtail muscle did $16\%,\;10%\;and\;4\%$ by icing, partial freezing and freezing, respectively. On the other hand, the alkali-soluble protein in both fishes increased with storage time. Gel strength of fish meat paste product prepared with the muscle of conger eel decreased to $35\%$ by icing, $74\%$ by partial freezing and $76\%$ by freezing for 10 days compared to control, and the expressible water increased 1.6 times, 1.2 times and 1.1 times by icing, partial freezing and freezing, respectively, as much as that of control product.