• Food preservation and processing industry
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• v.7 no.1
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• pp.45-53
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• 2008

흑마늘의 이화학적 성분의 변화 및 항산화 활성에 대한 연구를 분석한 결과, 흑마늘의 색은 제조공정을 거치면서 L, a 및 b값이 모두 감소하였는데 내부색의 경우 가공 초기에 크게 감소하였다. 수분은 가공 중 계속해서 감소하였고, pH도 점차 산성화되어 가공이 끝난 시료에서 pH $4.22{\pm}0.02$였다. 총 페놀 화합물과 플라보노이드는 1단계시료에 비해 최종단계에서 각각 약 1.9배, 2.6배 증가하였다. Total pyruvate와 thiosulfinate도 비슷한 패턴으로 각각 약 1.6배, 5.8배 증가하였다. 유리당 중 가장 함량이 높은 fructose는 1단계에서는 $1,403.03{\pm}6.24\;mg/100\;g$ 였던 것이 4단계에서는 $2,454.45{\pm}4.20\;mg/100\;g$으로 증가하였으나, 반면에 이당류인 sucrose와 maltose는 흑마늘의 숙성과 더불어 서서히 감소하는 경향이다. 흑마늘의 구성아미노산은 glutamic acid의 함량이 가장 많았고, 다음으로 proline과 aspartic acid였으며, 유리아미노산은 taurine, homocysteine 및 $\delta$-hydroxylysine은 1단계 혹은 2단계 시료에서는 검출되지 않았으나, 2단계 혹은 3단계 이후시료에서 미량 검출되었다. 흑마늘 가공중 물추출물과 에탄올 추출물의 DPPH에 대한 전자공여능은 숙성이 진행될수록, 추출물의 첨가 농도를 높일수록 점차 증가하여 4단계 시료의 $1,000\;{\mu}g/mL$ 농도에서 에탄올 추출물은 $45.63{\pm}0.43%$, 물추출물은 $67.40{\pm}0.21%$로 시험된 시료 중 가장 높은 활성을 보였다. 환원력은 100 및 $500\;{\mu}g/mL$ 농도에서 1, 2단계 시료를 제외한 모든 시료에서 물추출물이 에탄올 추출물 보다 높은 활성을 보였다.

• Food Science and Preservation
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• v.20 no.5
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• pp.643-649
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• 2013

The antioxidant activity and amino acid composition of various Cheonggukjang extracts, such as the water extract from Cheonggukjang (CWE), the alcohol extract from Cheonggukjang (CEE), the water extract from Cheonggukjang with black garlic (BWE) and the alcohol extract from Cheonggukjang with black garlic (BEE), were examined to investigate the effect of black garlic on the sensory quality and functional properties of Cheonggukjang. The total polyphenol contents of various extracts were 7.03 mg/100 g (BWE), 3.64 mg/100 g (CWE), 2.88 mg/100 g (BEE) and 0.81 mg/100 g (CEE). The radical scavenging activity of the DPPH radical was highest in BWE (91.83%), followed by BEE (37.35%), CWE (25.54%) and CEE (14.80%), in that order. The SOD-like activity was highest in BWE (20.20%), followed by BEE (9.22%), CWE (7.91%) and CEE (6.45%). The thiobarbituric acid reactive substances (TBARS) were highest in BWE (35.18%), followed by BEE (28.33%), CWE (17.40%) and CEE ((14.93%). The total amino acid content of Cheonggukjang (CC) was higher than that of Cheonggukjang with black garlic (CCWB), but the essential amino acid content of CCWB (43.18%) was higher than that of CC (42.27%). The 27 kinds of free amino acid were found in CC, but only 23 kinds were found in CCWB. The L-lysine content was highest (9.23%) in CC, and the L-phenylalanine content was highest (23.14%) in CCWB. The free amino acids (L-threonine, L-serine, L-sarcosine, L-proline, L-alanine, L-valine and D,L-${\beta}$-aminoisobutyric acid) were found in CC but not in CCWB. The ${\gamma}$-amino-n-butyric acid (GABA) was found in CCWB but not in CC. These results suggest that the addition of black garlic has beneficial effects on the functionality of Cheonggukjang without decreasing its sensory characteristics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.1
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• pp.52-60
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• 2004

The optimized in vitro culture system was investigated for improvement of regeneration efficiencies by observing the responses of scutella-derived callus of Korean rice (Oryza sativa L.). Large variations of callus induction (43.9-93.9%) and shoot regeneration (0-88.7%) were observed among the rice cultivars depending on medium. However, shoot regeneration was significantly improved by selected utilization of basal medium, growth regulators, and carbon sources. N6 basal medium was more efficient for embryogenic callus induction than MS or LS basal medium, while MS was superior to N6 for shoot regeneration. The calli of highly regenerative cultivars grew faster and showed higher rates of green tissue formation (GT) and shoot regeneration (SR) and lower rate of callus browning (CB) than those of recalcitrant cultivars. Although a higher level of kinetin stimulated the GT and SR in highly regenerative cultivars, $10\textrm{mgL}^{-1}$ kinetin generally suppressed the GT and SR, while CB was accelerated compared to $2\textrm{mgL}^{-1}$ kinetin. Additional benefits of sorbitol combined with maltose (or sucrose) under $5\textrm{mgL}^{-1}$ kinetin were certainly confirmed on regeneration efficiencies compared to sucrose alone as carbon source and osmotic regulator. This combination showed high rate of GT and SR with multiple shoots while low rate of CB. With MSRK5SM-Pr medium ($5\textrm{mgL}^{-1}$ kinetin, 3% sorbitol, 2% maltose, $500\textrm{mgL}^{-1}$ proline), the regeneration efficiencies of total 17 out of 24 cultivars were practically improved 160% on average compared to MSRK2S ($2\textrm{mgL}^{-1}$ kinetin, 3% sucrose) control medium. Especially, the medium was most effective to the cultivars showing a medium level of regenerability such as Daesanbyeo and Dongjinbyeo and Suwon477, enhancing efficiencies more than 300-600% compared to MSRK2S medium.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.505.2-506
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• 1986

L-Azetidine-2-carboxylic acid (A-2-C), a four-membered cyclic imino acid has been identified in certain plants, and the microorganism Actinoplanes ferrugineus. The imino acid A-2-C has a physiological significance as an antgaonist of proline during peptide synthesis. The biosynthetic mechanism for the formation of A-2-C has not been studied in any detail. By using various amino acids such as methionine and S-adenosyl-L-methionine labeled with deuterium or carbon-14, the details of the biosynthetic pathway and a possible mechanism for the formation of L-A-2-C in .4. ferrugineus have been unravelled, Both in vivo and in vitro experimental results suggest the biosynthesis of L-A-2-C is mediated by a confactor containing a carbonyl group, probably pyridoxal Phosphate. S-Adenosyl-L-methionine, which seems to be the direct biosynthetic substrate, has undergone a f-displacement by an ${\alpha}$-amino group of the amino acid portion of the substrate S-adenosyl-L-methionine potentially via a vinylglycine intermediate. The overall stereochemical events at the ${\beta}$-carbon of the substrate have been shown to inversion of configuration. The overall stereochemical events at the -position of the sub- strate have also been shown to occur with inversion of configuration. The ${\beta}$, ${\gamma}$-elimination reaction of the substrate seems to follow a cisoidal-type mechanism and the addition portion of the reaction a transoidal-type mechanism . The assignment of the proton NMR of A-2-C has been deduced by apply- ing NOE difference experiments, Gd(III) line-broadening experiments and 2D-NOESY experiments of regio-and stereospecificially deuterated A-2-C's.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.1-6
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• 2009

In order to optimize tissue culture conditions for genetic transformation of zoysiagrass (Zoysia japonica Stued.), the effect of plant growth regulators and culture medium supplements on embryogenic callus induction from mature seeds of a cultivar 'Zenith' were investigated. The optimal concentration and treatment period of NaOCl is 30% (v/v) for 60 minutes. Cultivation of mature seed on the callus Induction medium containing 3 mg/L 2,4-D and 3 mg/L dicamba showed 17.5% of embryogenic callus formation frequency. Supplementation of 1 g/L casein hydrolysate and 500 mg/L L-proline improved frequency of embryogenic callus induction. Audition of the medium with 5 mg/L $AgNO_3$ and 20 mg/L cysteine enhanced frequencies of embryogenic callus induction. Efficient callus induction system established in this study will be useful for molecular breeding of Boysiagrass through genetic transformation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.1
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• pp.23-30
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• 1999

The conditions for callus formation and plant regeneration were confirmed in four varieties of alfalfa(Medicago sativa L.). Among four varieties of alfalfa, "Vernal" expressed the highest rate for both of callus formation and plant regeneration. Otherwise, among SH(Schenk and Hildebrandt), MS(Murachige and Skoog) and N6 medium (Chu), SH medium was highest degree of efficiencies respectively in callus formatio and plant regeneration. In this study, we determined volume of hormones and other compounds appended in media. For callus formation, only $3mg/{\ell}$ of 2,4-D (2,4-dichlorophenoxy acetic acid) was appended in their media. For plant regeneration, the three kinds of media were used; the medium appended $5mg/{\ell}$ of NAA (1-naphtalene acetic acid) and $2mg/{\ell}$ of kinetin (6-furfurylaminopurine), the medium appended $11mg/{\ell}$ of 2,4-D and $1mg/{\ell}$ of kinetin, and the medium appended $1.6g/{\ell}$ of ammonium sulfate and $5.75g/{\ell}$ of proline. We obtained alfalfa plants from callus by regeneration, about sixty five days later transfer calli to regeneration media.

• Journal of Animal Science and Technology
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• v.46 no.1
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• pp.91-96
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• 2004

It is generally believed that amino acids occurring naturally in mammals are of the L-configuration. D-amino acid(DM) are common in nature as constituents of bacterial cell walls and several antibiotics. Recent reports have demonstrated the presence of small amounts of free DM in milk. The presence of free DM may affect the food quality by decreasing the nutritional value. Our objective was to examine whether the free DM carne from psychrotrophic bacteria. Free DM was produced by treating raw milk with Pseudomonas spp. The samples were extracted with sulphosalicylic acid and derivatized with AccQ-$Tag^{TM}$ reagent when the analysis was carried out by reverse-phase HPLC. We tested correlations of the content of free DM with bacterial growth. Significant amounts of free D-a1anine and D-proline have been found in the raw milk inoculated with Pseudomonas spp. The increase of D-alanine and D-proline appeared to be mainly related to the presence of Pseudomonas fluorescens. These results suggest that free DM may be considered as an indicator of psychrotrophic bacterial milk contamination.

• Food Science and Preservation
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• v.23 no.4
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• pp.488-494
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• 2016

Cheonggukjang was prepared by addition of peanut (Arachis hypogaea L.) powder in order to improve its quality and functional properties. The physicochemical and sensory properties of Cheonggukjang added peanut powder were investigated, after adding the peanut powder with the amount of 5, 15 and 25% (w/w). The proximate composition of peanut powder was as follows: moisture, 1.80%; crude protein, 24.9%; crude lipid, 48.3%; crude ash, 2.90%; and carbohydrates, 22.1%. Crude protein and lipid content of Cheonggukjang increased with increaes in the amounts of peanut powder, while the moisture content decreased. Calcium and amino acid contents showed disparity depending on the increasing addition of peanut powder. Cheonggukjang containing 15% (w/v) peanut powder was found to be highest calcium contents. The major amino acids of Cheonggukjang were glutamic acid, aspartic acid, lysine, leucine, arginine and proline. Depending on increasing amounts of peanut powder, the L and b values (measured using Hunter's color values) were decreased, while the a value was increased. In addition, pH was decreased as the amount of peanut powder was increased. Sensory scores of Cheonggukjang containing 15% (w/v) peanut powder were best when considering both quality characteristics and sensory evaluation. This study suggested that peanut powder could enhance the quality and functionality of Cheonggukjang further.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.547-559
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• 1994

To effectively utilize fish skin wastes from marine manufactory, the optimal extraction conditions to prepare gelatin from fish skins of Alaska pollack, cod and yellowfin sole were investigated. In addition, the physical properties of the fish skin gelatins prepared under the optimal extraction conditions were compared with the commercial animal skin gelatin. The conditions for extraction of gelatins from fish skins were as follows ; The skins were limed with 1.0~1.5%(w/v) calcium hydroxide solution. The fish skin gelatins were extracted with 6~7 volumes of water(pH 6.0~7.0) for 5hrs at $40{\sim}50^{\circ}C$, and the yield of Alaska pollack skin gelatin extracted under the above conditions was higher than those of cod and yellowfin sole skins. The heavy metal contents, jelly strength and electric conductivities of fish skin gelatins were lower than those of a commercial gelatin(bovine skin), but the viscosity and isoelectric point were higher. The amount of amino acid in fish skin, such as gelatin, glutamic acid, serine, threonine, methionine and cysteine, were higher than those in pig and ox skin. However, the contents of hydroxyproline and proline were lower.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.127-131
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• 2006

A study was carried out to produce antimicrobial peptides from zein treated with pretenses of six kinds. Among the pretenses of six kinds, zein hydrolysate treated with pepsin showed the highest antimicrobial activity. The zein hydrolysate with pepsin was fractionated with membrane filter (30,000 10,000 and 3,000 molecular weight cut-off) and antimicrobial activity was measured for each fractions. Antimicrobial activity appeared greatly in the fraction below 3,000 (molecular weight cut-off) . The fraction was re-fractionated by HPLC and substances of two peaks collected as a sample to measure antimicrobial activity. All of both peaks showed the antimicrobial activity but 1st peak exhibited a consistently higher antimicrobial activity than 2nd peak. Minimum inhibitory concentrations (MIC) were between 2.5 and 3.0 mg/mL. The peptide was heat-stable since antimicrobial activity was maintained after treated with heat for 20 min at $121^{\circ}C$. N-terminal amino acid sequence of peptide fractionated by HPLC was leucine, glutamic acid, proline, phenylalanine, aspartic acid and argenine. These results indicated that peptide isolated from zein hydrosate with pepsin can use as a natural preservative ingredient in food industry.