Earticle

The exposure of food to ionizing radiation has been recognized as a safe and effective mode of food preservation in more than 55 countries. The benefits include eradication of insect pests, inactivation of food pathogens, extension of shelf-life, and improvement in food hygiene. Regulatory authorities around the world have emphasized the implementation of various national and international regulations to facilitate trade and development of consumers’confidence in purchasing irradiated foods. Therefore, the need for reliable irradiation detection methods has increased to enforce these regulations. At present, a number of promising analytical approaches have been developed and evaluated. Moreover, about 10 European Standards have been adopted as General CODEX Alimentarius methods for the detection of irradiated foodstuffs. However, most of these methods demand relatively expensive equipment and prolonged sample preparation. Therefore, simple and cost-effective approaches would be advantageous for rapid screening of foodstuffs. The suspected samples need to be analyzed further with more validated techniques to confirm the screening results. In this review, existing screening methods (i.e. physical, chemical, and biological) for the identification of irradiated foods have been outlined along with their principles, scopes and limitations.

To investigate the effects of co-solvents on the morphology of nano-scale zein materials, zein solutions were electrospun with different co-solvent ratios of EtOH/H2O. Different zein solution concentrations were used to study the effects of the zein content on the electrospun materials. The resulting electrospun materials were all characterized using field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The diameters of the electrospun nanoparticles and nanofibers were found to increase when increasing the EtOH ratio at certain zein concentrations. Furthermore, increasing the zein content changed the morphology of the electrospun materials from nanoparticles to nanofibers.

This work attempted to fabricate organic/inorganic nanocomposite by combining organic cellulose nanofibrils (CNFs), isolated by 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO)-mediated oxidation of native cellulose with inorganic nanoclay. The morphology and dimension of CNFs, and tensile properties and thermal stability of CNF/clay nanocomposites were characterized by transmission electron microscope (TEM), tensile test, and thermogravimetry (TG), respectively. TEM observation showed that CNFs were fibrillated structure with a diameter of about 4.86±1.341 nm. Tensile strength and modulus of the hybrid nanocomposite decreased as the clay content of the nanocomposite increased, indicating a poor dispersion of CNFs or inefficient stress transfer between the CNFs and clay. The elongation at break increased at 1% clay level and then continuously decreased as the clay content increased, suggesting increased brittleness. Analysis of TG and derivative thermogravimetry (DTG) curves of the nanocomposites identified two thermal degradation peak temperatures (Tp1 and Tp2), which suggested thermal decomposition of the nanocomposites to be a two steps-process. We think that Tp1 values from 219.6℃ to 235℃ resulted from the sodium carboxylate groups in the CNFs, and that Tp2 values from 267℃ to 273.5℃ were mainly responsible for the thermal decomposition of crystalline cellulose in the nanocomposite. An increase in the clay level of the CNF/clay nanocomposite predominately affected Tp2 values, which continuously increased as the clay content increased. These results indicate that the addition of clay improved thermal stability of the CNF/clay nanocomposite but at the expense of nanocomposite’s tensile properties.

As a specialty oil, furan fatty acids have gained special attentions since they are known to play important roles in biological systems including human. Although several studies reported chemical synthesis of furan fatty acids, their synthesis consisted of complicated chemical multistep with chemical catalysts. Recently, a simple one-step heat treatment method was developed to produce a novel furan fatty acid, 7,10-epoxy-octadeca-7,9-dienoic acid (7,10-EODA) from a dihydroxyl fatty acid 7,10-dihydroxy-8(E)-octadecenoic acid (DOD). In this report we studied about optimization of environmental conditions for the maximum production of 7,10-EODA from DOD by heat treatment. Production of 7,10-EODA was maximized at over 85℃ for at least over 48 hour in hexane. Solvent volume for maximum production should be over 300 mL per 10 mg DOD.

Bacillus subtilis and Bacillus amyloliquefaciens are closely related species that share a similar genomic background, and are both known to secrete large amounts of proteins directly into a medium. The extracellular proteomes of two strains of Bacillus subtilis and two strains of Bacillus amyloliquefaciens were compared by 2-D gel electrophoresis during the late exponential growth phase. The relative abundance of some minor protein spots varied among the four strains of Bacillus. Over 123 spots of extracellular proteins were visualized on the gel for B. subtilis CH 97, 68 spots for B. subtilis 3-5, 230 spots for B. amyloliquefaciens CH 51, and 60 spotsfor B. amyloliquefaciens 86-1. 2D gel electrophoresis images of the four Bacillus strains showed significantly different protein profiles. Consistent with the 2D gel electrophoretic analysis, most of the B. subtilis proteins differed from the proteases secreted by the B. amyloliquefaciensstrains. Among the proteins identified from B. subtilis, approximately 50% were cytoplasmic and 30% were canonically extracellular proteins. The secreted protein profiles for B. subtilis CH 97 and B. subtilis 3-5 were quite different, as were the profiles for B. amyloliquefaciens CH 51 and 86-1. The four proteomes also differed in the major protein composition. The B. subtilis CH 97 and B. amyloliquefaciens CH 51 proteomes both contained large amounts of secreted hydrolytic enzymes. Among the four strains, B. subtilis 3-5 secreted the least number of proteins. Therefore, even closely related bacteria in terms of genomic sequences can still have significant differences in their physiology and proteome layout.

본 연구의 목적은 온실설계 시 야간복사열 손실량 예측을 위한 천공온도를 산정하는데 필요한 적절한 계산식을 제시하는 것이다. 대구지역의 운량에 따른 야간천공온도를야간복사계를 이용하여 측정하고 기존의 식들을 이용하여 계산하였다. 천공온도를 계산하기 위한 최적의 식을찾아내기 위하여 측정값과 계산값을 비교하였다. 운량의 크기에 따라 대기온도와 천공온도의 차이가 달랐으며 운량이 감소함에 따라 온도차는 점차 증가하였다. 맑은 날이구름 낀 날과 비온 날에 비해 약 10∼20배 정도의 더 높은온도차를 나타내었으며 온도차가 큰 맑은 날이 복사냉각이크다는것을확인할수있었다. 맑은날에대하여계산된천공온도와 측정된 천공온도와의 상관성을 분석한 결과Bliss식과 Clark and Allen 식이 다른 식들에 비해 상관성이비교적더높은것으로나타났다. 구름낀날에대해계산된천공온도와 측정온도와의 상관성을 분석한 결과 Fuentes식이 가장 잘맞는 것으로 나타났다. 구름낀날의천공온도를 산정할 수 있는 새로운 식을 제안하였다.

To estimate the radiative heat loss from greenhouses, a new equation for calculating the sky temperature is presented. The sky temperature in the Daegu region was measured using a pyrgeometer and calculated using different equations according to the cloudiness. The calculated and measured results were then compared to identify the best equation for calculating the sky temperature. The difference value between the air and sky temperature was dissimilar and increased as the cloud amount decreased. On clear days the difference value was 10∼20 times greater than that on cloudy and rainy days. When analyzing the correlationship between the calculated and measured sky temperatures on clear days, Bliss’s and Clark & Allen’s equations were found to be superior to the other equations. However, on cloudy days, the best correlationship between the calculated and measured sky temperatures was exhibited by Fuentes’s equation. Therefore, a new equation is proposed for calculating the sky temperature on a cloudy day.

새로운 유전자원을 창출하기 위해 풍산나물콩에 EMS를 처리한 후 돌연변이 집단을 육성하고, 돌연변이 계통 중 지방산 함량에 대한 변이체를 찾아 콩 유전육종 재료를 선발하고자 실시한 결과를 요약하면 다음과 같다.M2 3,744개체중 형태적 변이를 보이는 1,000개체를 선발하여 M4 세대에서 난쟁이형 (3.3%), 엽형변이 (2.6%), 엽록소결핍 (1.5%), 꽃색변이 (1.1%), 엽형변이를 보이는 난쟁이형 (0.2%)의 변이가 관찰되었다. 야생형인 풍산나물콩의지방산 함량은 palmitic acid 11.6%, stearic acid 3.4%, oleicacid 25.3%, linoleic acid 52.0%, linolenic acid 8.1%를 나타내었다. M4 892 개체의 종자지방산 함량을 분석한 결과palmitic acid, stearic acid, oleic acid, linoleic acid, linolenicacid 함량은 각각 7.4~19.7%, 2.2~13.0%, 14.7~49.0%, 31.8~63.9%, 3.9~15.9%의 범위를 나타내었고, 10.8%, 3.8%25.3%, 52.0%, 8.1%의 평균을 보였다. 각각의 지방산 별로 선발된 돌연변이 개체들은 다음과 같다. 고 palmitic acid함량을 나타내는 PE1542 (17.1%), PE3058 (17.0%), 고 stearicacid 함량을 나타내는 PE977 (12.7%)와 저 stearic acid 함량을 나타내는 PE2166 (1.9%), 고 oleic acid 함량을 나타내는PE450 (44.4%), PE2742 (47.7%), PE3058 (33.4%), 저 linolenicacid 함량을 나타내는 PE594 (4.6%), PE1690 (3.7%)와 고linolenic acid 함량을 나타내는 PE2166 (12.6%) 등이 선발되었다.

Mutagenesis is used to study gene function and obtain new genetic resources for plant breeding. Soybean is an important oil crop in the world. Thus, to find new genetic resources, a mutation population was developed from the soybean cultivar Pungsannamul using 0.3% ethyl methane sulfonate. The variation of fatty acids was then evaluated among 892 M4 generation mutant lines selected from 3,774 mutant lines. While the wild type Pungsannamul showed 11.6, 3.4, 23.8, 53.3, and 7.8% for palmitic, stearic, oleic, linoleic and linolenic acid, respectively. the fatty acid variations in the mutant lines ranged from 7.4 to 19.7%, 2.2 to 13.0%, 14.7 to 49.0%, 31.8 to 63.9%, and 3.9 to 15.9% with an average of 10.8, 3.8, 25.3, 52.0, and 8.1% for palmitic, stearic, oleic, linoleic and linolenic acid, respectively. Thus, two mutation lines with higher plamitic acid, PE1542 (17.1%) and PE3058 (17.0%), one line with lower stearic acid, PE2166 (1.9%), one line with higher stearic acid, PE977 (12.7%), two lines with higher oleic acid, PE450 (44.4%) and PE2742 (47.7%), and two lines with lower linolenic acid, PE594 (4.6%) and PE1690 (3.7%), were selected from this study. The newly selected fatty acid variants will be good genetic sources for gene function analyses and breeding soybean varieties with altered fatty acids for various industrial and human food applications.

예로부터 다양한 방면에서 약용식물로 널리 사용되어 온 감초에서 분리한 dehydroglyasperin C (DGC)는 이전의 연구에서 세포 모델계에서 비교적 높은 항산화 능력과 2상 해독효소계 활성을 유도하는 것이 확인되었으나, 동물 모델계에서 DGC의 항산화능과 2상 해독효소계를 평가하였을 때, 유의적 결과가 관찰되지 않았다. 따라서 DGC 처리시간에 따라 마우스의 장기 및 혈장에 어떠한 영향을 미치는지를 알아보고자 0, 2, 4, 6, 8, 12, 24 시간 동안 DGC를 처리한 후, 장기별 QR 유도활성과 간과 신장에서의 단백질 발현 패턴, 혈장의 항산화능력을 측정하였다. 그 결과 DGC 처리에 의한 QR 유도활성은 위, 대장에서 시간에 따라 변화하는 경향을 보였고, 간, 신장, 소장, 폐에서는 큰 경향성이 나타나지 않았으며, 2상 해독효소의 단백질 발현 패턴은 간에서는 역시 큰 경향성이 나타나지 않았고 위에서는 QR 유도활성과 유사한 경향이 나타남을 확인하였다. 혈장의 DGC 처리 시간에 따른 항산화활성은 시간에 따라 유의적으로 값이 증가한 것을 확인할 수 있었다. 결론적으로 DGC는 처리 시간에 따라 각 장기 및 혈장에 각기 다르게 영향을 미치는 것으로 사료되며, 앞으로도 추가적인 연구를 통하여 DGC의 효능을 보다 구체적으로 검증하는 것이 필요한 것으로 생각된다.예로부터 다양한 방면에서 약용식물로 널리 사용되어 온감초에서 분리한 dehydroglyasperin C(DGC)는 이전의 연구에서 세포 모델계에서 비교적 높은 항산화 능력과 2상 해독효소계 활성을 유도하는 것이 확인되었으나, 동물 모델계에서 DGC의 항산화능과 2상 해독효소계를 평가하였을 때, 유의적 결과가 관찰되지 않았다. 따라서 DGC 처리시간에 따라 마우스의 장기 및 혈장에 어떠한 영향을 미치는지를 알아보고자 0, 2, 4, 6, 8, 12, 24 시간 동안 DGC를 처리한 후, 장기별 QR 유도활성과 간과 신장에서의 단백질 발현 패턴, 혈장의 항산화능력을 측정하였다. 그 결과 DGC 처리에 의한 QR 유도활성은 위, 대장에서 시간에 따라 변화하는 경향을 보였고, 간, 신장, 소장, 폐에서는 큰 경향성이 나타나지 않았으며, 2상 해독효소의 단백질 발현 패턴은 간에서는 역시 큰 경향성이 나타나지 않았고 위에서는 QR 유도활성과 유사한 경향이 나타남을 확인하였다. 혈장의 DGC 처리 시간에 따른 항산화활성은 시간에 따라 유의적으로 값이 증가한 것을 확인할 수 있었다. 결론적으로 DGC는 처리 시간에 따라 각 장기 및 혈장에 각기 다르게 영향을 미치는 것으로 사료되며, 앞으로도 추가적인 연구를 통하여 DGC의 효능을 보다 구체적으로 검증하는 것이 필요한 것으로 생각된다.

Licorice, Glycyrrhizae radix, is one of the oldest and most frequently used botanicals in the oriental medicine. Our previous study showed that dehydrolyasperin C (DGC) isolated from licorice had antioxidant activity and induced phase 2 detoxifying enzymes in mouse hepatoma cells. Therefore, this study was conducted to investigate the effect of exposure time to DGC on quinone reductase (QR), one of the anticarcinogenic biomarkers, and antioxidant potential of plasma using animal model. ICR mice were divided into 7 groups, in which mice in each group were injected with DGC (5 mg/kg b.w.) for 0, 2, 4, 6, 8, 12, 24 hours respectively. Following the treatment the organs including liver, kidney, lung, stomach, large intestine, small and large intestines were collected and subjected to QR activity assay, western blotting, and FRAP assay. Exposure to DGC caused a significant induction of QR activity in stomach and large intestine of mice. Ferric reducing activity of plasma, a typical biomarker for antioxidative potentialshowed that DGC improved antioxidant potential in mice. However, no significant effect of DGC was observed in the other organs.

본 연구에서는 소비자의 새로운 색상에 대한 다양한 욕구를 충족시키기 위하여 백색 장미 데니스(R. hybrida'Denice')를 사용하여 무지개 색상의 장미를 만들고자 하였다. 온도가 높을수록 염색 시간은 빨랐으나 높은 온도에서는 절화의 개화가 빠르게 진행되었으며, 4시간 이상에서는꽃잎의 끝이 너무 진하게 염색되거나 건조되는 현상이나타났다. 7.5g·L-1보다 11g·L-1이상의 염료농도에서 염색되는 속도가 빨랐으나 큰 차이는 없었다.개화정도는 완전봉오리에서 시각적으로는 빨리 염색이되는 것으로 보였으나 속 꽃잎까지 흡수되는 시간은 3처리모두 유사하였다. 그러나 상품가치 면에서는 바깥꽃잎이3~4장 정도 개화했을 때가 가장 적합하다고 판단되었다.단색 실험의 결과에서 가장 적합한 조건 즉, 20℃염료 용액에 3시간 침지, 화경장 30cm, 11g·L-1의 염료 농도, 바깥꽃잎이 3~4장 개화한 ‘Denice’ 장미에 Hot Pink, True Blue,Yellow 3가지 색상을 조합하여 염료를 물올림 한 결과,6가지 색상을 지닌 무지개색의 장미를 착색, 발현시킬 수있었다.

This research was carried out to produce rainbow-colored roses from white cut rose, Rosa hybrida 'Denice', to meet customers' desire of having various colors of roses. The higher temperature of dyeing solution used, the faster coloring time surveyed. In high temperature, the flowering speed of cut flower accelerated and after treating more than 4 hours, the edges of flowers became too dark or dry. In the condition of concentration of dyeing solution, 11g·L-1 dyed faster than 7.5g·L-1 , however, no differences between 15g·L-1 and 11g·L-1 have observed. It looked fast coloration at the stage of early blooming, but all three different petal opening stages need similar time to get even coloration from outer to inner petals. For the consideration of commercial value, flowers with 3-4 petals opened are better quality than flowers with less petals opened. It was possible to make rainbow-colored rose by dipping 'Denice' with 3 primary color combination, Hot Pink, True Blue, and Yellow dyes, at the best result conditions of 20℃ solution temperature, 3-4 petals opening stage, 11g/L concentration of dye solution and 3 hours dipping, respectively.

본 실험은 한국에서 여름철 동안 야간 고온이 스프레이국화의 개화기간에 미치는 영향을 확인하기 위해 수행하였다. 2005년 실험결과에 따르면, 단일기간 중 야간 온도가 25°C 이상 지속된 기간은 23.6일로 조사되었고 개화가 지연된 기간은 22일로 조사되었다. 유사한 결과가 2006년에도 조사되었는데, 단일기간 중 야간 온도가 25°C이상 지속된 기간은 23.6일, 개화지연 기간은 23일로 조사되었다. 2007년 결과도 단일기간 중 야간 온도가 25°C 이상 지속된 기간은 31.9일, 개화지연 기간은 31일로 조사되었다. 결론적으로 2005년부터 2007년까지의 결과에 따르면, 스프레이국화 ‘Euro’ 품종에서 야간에 고온과 개화기간지연 사이에 특별한 상관관계가 있을 것으로 추정된다.

This study identified the effect of night time temperatures on the flowering period of spray-chrysanthemum during the summer season in South Korea. According to the results for 2005, the temperature at night time sustained more than 25°C for 23.6 days during the short day period and delayed the flowering period for 22 days. Similar observations were reported in 2006, as the night time temperature sustained more than 25°C for 23.6 days during the short day period and delayed flowering period for 23 days. The results for 2007 year showed that night time temperature sustained more than 25°C for 31.9 days during the same period and delayed flowering for 31 days. In conclusion, based on the results for 2005 to 2007, a specific correlation was found between high night time temperatures and a delayed flowering period for the ‘Euro’ spray-chrysanthemum.