Ionic liquids (ILs) are organic salts with low melting point by asymmetric ionic strength between cation and anion. They have been known as promising DNA extraction, separation and preservation agent due to their hydrophilic, hydrophobic interaction with DNA. However, few studies have been performed about how DNA-ILs complexes form and their mechanism. Herein, we present three types of ionic liquids (EMIM-Cl, BMIM-Cl, and OMIM-Cl) change the DNA structure depend on alkyl chain length of ionic liquids. Structural changes of DNA by ionic liquids are observed by Atomic force microscopy, gel electrophoresis, zeta potential and solid-state nanopore technology. The results of AFM show the different structures of DNA, including aggregate, stretching, and bundling shapes in terms of EMIM-Cl, BMIM-Cl, and OMIM-Cl respectively. In DNA translocation experiment, DNA/EMIM-Cl show rare translocation signal due to aggregated structure by neutralized surface charge. DNA/BMIM-Cl and DNA/OMIM-Cl show slowing down the translocation speed due to changes of DNA net charge and structure. Especially, OMIM-Cl make slowing down the DNA translocation speed about 102~104 times compared to translocation speed of bare DNA by unzipping the bundling shape of complex. In conclusion, the morphology of DNA could be modified by the incorporation with different alkyl chain length of ILs, providing their further application in nanopore technique for slowing DNA sequencing or understanding protein-DNA interaction.

In the present study, we investigated the protective effect of various grain methanolic extracts against UVB-induced photo-aging in human skin fibroblasts. Various grain methanolic extracts were evaluated for their antioxidant compounds and activities. 2,2-Ddiphenyl-1-picryhydrazyl radical (DPPH) and ABTS 2,2-azino-bris-(3-ethylbenzoth iazoline-6-sulphonic acid) radical cation scavenging activities have been used to measure the relative antioxidant activities of extracts from grains. The content of total polyphenolics in the extracts were evaluated using spectrophotometric methods. Human skin fibroblast (Hs68) cells were pretreated with various grain methanolic extracts (25 μg/mL). Skin toxicity was simulated by exposing the cells to UVB (30 mJ/cm2) irradiation. In response to the UVB-irradiation, an increased amount of matrix metalloproteinases (MMPs) release was observed, whereas pretreatment of various grain methanolic extracts significantly inhibited the production of MMP-1 in Hs68 cells. We also found that pretreatment of the extracts significantly decreased UVB-induced reactive oxygen species and significantly increased total collagen content in Hs68 cells. These results provide that grains could be regarded as a potential ingredient in natural cosmetics, used for UVB protection.

본 연구는 옥수수수염 추출 후 미세캡슐화 과정에서 피복제의 종류에 따른 이화학성질을 대조군과 비교분석하였다. 에탄올 추출 후 Celluclast 1.5L FG 효소처리를 한 시료를 핵물질로 사용하였으며 피복물질로는 말토덱스트린(MD), 사이클로덱스트린(CD), 말토덱스트린과 사이클로덱스트린(MD-CD)을 1:1 로 혼합한 세 가지 피복물질을 이용하였다. 주사전자현미경으로 1,800배 확대한 후 표면미세구조를 분석한 결과 대조군의 표면은 구형의 상태로 확인 되었으나 캡슐화 분말의 입자표면구조는 구형이 아닌 다양한 형태로 나타났으며 MD 처리군의 표면미세구조는 거칠게 나타났다. 미세캡슐화 전과 후의 입자분포를 비교하여보면 대조군의 평균 직경인 28.84μm에서 MD, CD, MD-CD 미세캡슐화의 경우 각각 5.67, 3.61, 3.85μm로 작아졌다. 미세캡슐화 분말의 수분흡수지수 및 수분용해지수의 경우 대조군의 수분흡수지수는 0.68로 가장 큰 값을 보였으며 미세캡슐화 시료는 0.20-0.26이었으며 MD-CD 처리군이 0.20으로 가장 작은 값으로 나타났다. 수분용해지수에서는 대조군이 72.23%로 가장 작았으며 CD 처리군이 95.23%로 가장 크게 나타났다. 총 메이신 함량에서는 대조군의 경우 3752.79 mg/100 g이었으며 미세캡슐화 시료에서는 2338.85-3338.20 mg/100 g의 범위이었고 MD-CD 처리군이 3338.20 mg/100 g으로 처리군 중 가장 높은 함량을 보였다.

Starch is an abundant, renewable, and low cost material that has been extensively studied for its role in crystallization. The aim of this study is to develop a convenient and green approach to synthesize starch nanoparticles (StNPs). Short glucan chains were successfully prepared by using pullulanase that could debranch the amylopectin obtained from waxy maize starch. StNPs were prepared via the self-association of short glucan chains, of which the crystallinity structure changed from A-type (native starch) to B-type (starch nanoparticles) through the enzymatic hydrolysis and reassembly process at 4°C. Scanning electron microscopy (SEM), X-ray diffraction (XRD), dynamic light scattering (DLS) and differential scanning calorimetry (DSC) were used to characterize the morphology and crystalline structure of StNPs. The results showed that the diameter of StNPs ranged from 300 nm to 1.5 μm, depending on the initial concentration of short glucan chains and self-assembly time. The developed approach could produce well-defined and uniform starch nanoparticles that could readily be employed to encapsulate various functional guest molecules in biocompatible starch based nanoparticles in food industry.

광펄스 살균은 제품에 열을 발생시키지 않고 포장된 상태로 제품을 살균할 수 있어 신선제품의 유통기한을 연장시킬 수 있는 기술이다. 본 연구에서는 포장재질로 많이 사용되고 있는 PP, OPP, PE, 그리고 PET 등 포장 필름 재질에 따른 광펄스 살균효과에 대해 알아보았다. PP의 경우에는 20 μm 두께에서 20초 처리시 6 log 정도의 사멸 효과를 보였으며, 60초 처리 후에는 모든 균이 사멸되었고, 두께에 따라 사멸율에 큰 차이는 없었으나 점차 감소하는 경향을 보였다. OPP와 PE의 경우에는 30 μm 두께에서 30초 처리시 6 log, 60초 후에는 모든 균이 사멸하였다. PET의 경우에는 다른 포장 재질에 비해 낮은 살균 효과를 나타내었다. 필름 재질별 빛의 투과율은 PET를 제외하고는 큰 차이를 보이지는 않았으나, PP가 가장 높은 투과율을 나타내었다. 포장재질의 두께가 두꺼워짐에 따라 빛의 투과율은 점차 낮아지는 경향을 보였으나 PET를 제외하고는 큰 차이를 보이지는 않는 것으로 나타났다.

Differences in sugar and salt penetrarion rates of radish depending on size and concentration of solution were examined. 2x2x2 and 4x4x4 cm cube-shaped radish examined in different pickling condition (salt 2, 4, 6, 8% and sugar 5, 10, 15, 20% brix). After 12hr storage, Salt penetration rate of radish cut into 2x2x2 cm was faster than that of 4x4x4 cm in all salt solution. Size dependent sugar penetration showed same tendency with size dependent salt penetration. Also, increase in salt and sugar concentration led to increase in salt and sugar permeation rate.

본 연구의 목적은 미꾸라지 진액 속의 용매의 종류와 농도에 따른 mucin의 함량을 확인하고 이의 특성을 연구하였다. 진액을 ethanol, acetone 및 aluminum sulfate 3종류의 용매를 사용하여 추출한 결과 ethanol에서 가장 높은 수율을 나타내었다. Ethanol의 농도를 60-100%로 하여 침전시켰을 때 침전물에 대한 mucin의 함량이 90%에서 가장 높았다. 중류수로 희석하여 제조한 다양한 농도(1.25%, 2.5%, 5%, 10%)의 mucin수용액 시료의 열 안정성을 측정했을 때 onset 온도, peak 온도 그리고 엔탈피에서 차이가 나타났다. Mucin침전물을 이용한 항균능력에서는 gram-negative균과 gram-positive균 모두에서 항균능력이 나타났으며 특히 gram-negative균에서 더 큰 항균능력이 나타났다. 이와 같은 미꾸라지 mucin의 농도에 따른 열안정성, 항균능력과 항산화능 성질 등을 이용하여 앞으로의 비 식품소재개발에 기초 데이터로 사용하고자 한다.

Retinol is a type of vitamin A that helps the skin's epidermal cells maintain their original function and plays an important role in visual acuity. However, retinol cannot simply be incorporated into foods in its pure form because of limited solubility and chemical instability. In this study, retinol was encapsulated within lipid droplets of oil-in-water (O/W) emulsion and the photo stability of retinol loaded in O/W emulsion was examined. O/W emulsions containing retinol were prepared using Tween 20, Decaglycerine myristate and WPI, respectively, at different oil concentrations (0.1, 0.5, 1.0, 2.0, and 4.0 wt%). Photo stability of retinol was determined by measuring retention rate (%) of retinol loaded in O/W emulsions after exposure to UV light for 24 h and compared to that of retinol dissolved in ethanol. The retinol retention rate was higher for O/W emulsions than retinol in ethanol and the retention rate increased as the oil concentration of emulsions increased, which might be attributed to the opaqueness of emulsions. As the oil concentration of emulsions increased, the turbidity of emulsions also increased. In terms of the type of emulsifier, decaglycerine myristate-stabilized emulsion had the highest retinol retentions rate than other emulsifier-stabilized emulsions after exposure to UV light. This study provides important information for designing effective emulsion-based delivery systems for improving the stability of retinol.

Glabridin (from licorice) and carnosic acid (from rosemary) are natural phenolic compounds which show the antioxidant and antimicrobial activities. Nevertheless, the use of licorice and rosemary extracts in food matrix is highly limited due to the low water solubility and poor chemical stability of active constituents of both extracts. Therefore, the aim of this study is to investigate the functionality and stability of O/W emulsions containing glabridin and carnosic acid for improving their efficiency for food application. To manufacture the O/W emulsions (10% oil, w/w), licorice and rosemary extracts were dispersed, respectively, in soy bean oil (3%, w/w) and then emulsified with various emulsifiers (decaglyceryl luarate, decaglyceryl monooleate, whey protein isolate and casein) using a high pressure homogenizer (10,000psi for 3 times). Particle size and ζ-potential of emulsions were then measured during the storage for 4weeks at room temperature. UV stability, antioxidant & antimicrobial activity were also tested. The size of oil droplets and the ζ-potential values remained within the margin of error during the 4weeks of storage. Core materials in extracts, glabridin and carnosic acid, incorporated into emulsion system were kept less damaged by UV rays than those dissolved in oil only. Antioxidant activity of emulsion systems remained significantly higher than that of oil system during storage period and also depended on the emulsifier type an increase in interfacial area in emulsion system might increase antioxidant activity of core materials dissolved in oil. The result obtained from the study could be beneficial for food industry interested in utilizing licorice and rosemary extracts.

Amylose is carbohydrate polymer defined as a linear natural polysaccharide composed of α(1→4) bound glucose units. Due to its abundance, renewable nature, low cost, and biodegradability, this polymer is regarded as a promising green material for producing crystals and particles of different sizes ranging from the nanometer scale to the micrometer scale. Herein, short amylose chains and dextran-coated iron oxide magnetic nanoparticles (Dex@MNPs) were introduced to fabricate individual superparamagnetic amylose microparticles (SAMPs), which have a well-defined spherical shape and a uniform size of about 1 μm. We found that the aggregation of SAMPs can be mediated by the introduced Dex@MNPs in a concentration-dependent manner, indicating that Dex@MNPs, as the seed crystals, play an important role in self-assembly of SAMPs. By using streptococcal protein G tagged with maltose binding protein (MBP-SPG), specific antibody against Escherichia coli O157:H7 was successfully immobilized on the surface of SAMPs. The Ab-functionalized SAMPs showed a high capture efficiency (>90%) comparable to the commercial immunomagnetic microparticles regardless of suspending agents (1X PBS and milk). Moreover, SAMPs exhibited excellent recyclability, in which the Ab immobilized on the surface of SAMPs can be refreshed by using the maltose elution buffer along with the unchanged capture efficiency. In addition, SAMPs were assembled into the linear rod-shape microstructure by the introduced magnetic field during the amylose-mediated precipitation process. The convenient self-assembly of SAMPs with the well-defined size and shape, biocompatibility, tolerance to environmental variances, high magnetic response behavior, and excellent recyclability in the functionalization make these magnetic microparticles promising for many potential applications such as bio-sensing, labeling, and smart delivery of active compounds.

Fermented food consists of a variety of lactic acid bacteria (LAB) that are also used in the industry as starter cultures. This genus comprises of different species that find importance as a preservatives in food like meat and sausages. Likewise, Lactobacillus brevis has been recognized as GRAS and is a potential probiotic strain extensively being used on an industrial scale. Since such bacteria are directly related to human health, there has been a need to identify and characterize them on the molecular level. In this study, LAB was identified and characterized from various fermented food samples available in South Korea. Two types to PCR-based molecular typing methods were used to analyze the 13 Lactobacillus brevis isolates, of which one was based on difference in the banding patterns originated on agarose gel and the other was related to the sequence analyses of various housekeeping genes in the particular strain. The former rep-PCR technique used three primers namely, REP, ERIC and (GTG)5 that amplified repetitive sequences in the genome and provided characteristic fingerprint profile for each isolate. This clustered the strains in 3 groups with the help of UPGMA method of clustering distinguishing between closely related strains. However, the latter multilocus sequencing typing (MLST) technique provided definite identification of the strains. A set of 7 housekeeping genes were determined as groEL, gyrB, rpoA, rpoB, pheS, recA and dnaK. These genes were amplified and sequenced and were subjected to comparative analysis. Discrete allelic profiles and 13 sequence types (STs) were resolved and minimum spanning tree (MST) was constructed, revealing the genetic relatedness among the isolates. On comparing the results from both the techniques, MLST proved to generate accurate and precise fingerprints owing to the sequence analysis of conserved genes thus providing a scope for research in the monitoring related species.

Recently, fruit vinegar made from fruit wine has been famous due to its health function and nutrition. Therefore, there are many fruit vinegar products manufactured by major big food companies and small company as well as one person through the internet shopping mall. In this study, 4 type citrus fruits vinegar (grapefruit, tangerine, orange, lemon) were investigated to find out the quality of vinegar for consumers’ wise selection. Commercial vinegar which are commonly produced by fermenting mixture of brown rice vinegar with fruit extracts were analyzed that sugar content, pH, acidity, turbidity, DPPH assay, FRAP assay, TPC and manufacture method. Among all samples, 4 tangerine vinegar acidity were suit with standard quality (4~29%) by MFDS. pH scale of all vinegar was from 2.76 to 3.48 and lemon vinegar was lowest. Average sugar content (brix%) was lowest at tangerine vinegar as 17.4. In the DPPH radical scavenging activity, there was no significant difference at all samples. In the TPC study and FRAP assay, lemon vinegar showed the highest value, while grapefruit, tangerine, and orange vinegar were not significantly different. From the result, product type, and qualities and suitability as vinegar product of various citrus fruits vinegar were observed and it was found that although product name is ‘vinegar’, some vinegar products were not suit with standard quality (acidity%).

상압 유전체 장벽 콜드 플라스마 처리(atmospheric dielectric barrier discharge-cold plasma treatment, DBD-CPT)를 이용한 살모넬라 저해 효과에 닭가슴살 큐브의 표면 특성이 미치는 영향과 살모넬라 저해를 위한 최적 DBD-CPT 조건 그리고 최적 조건의 DBD-CPT 가 닭가슴살 큐브의 품질 특성에 미치는 영향을 연구하였다. 분리 유청 단백(Whey protein isolate, WPI) 용액으로 코팅하거나 혹은 코팅하지 않은 닭가슴살 큐브(1.51.51.5 cm3, 3.8 g)를 준비하여 Salmonella (~7 log CFU/sample)를 접종하였다. 접종된 닭가슴살 큐브를 폴리 에틸렌 포장재 중심에 위치시킨 후 CP형성 전압(25-38.9 kV)과 처리 시간(2-5 min)에 대해 반응 표면 중심 합성법으로 설계한 처리 조건들로 DBD-CPT하였다. Salmonella 저해에 대한 최적 조건은 반응 표면 분석을 이용해 결정되었고 최적 조건의 DBD-CPT 가 닭가슴살 큐브의 품질 특성에 미치는 영향은 TBARS (thiobarbituric acid reactive substance values) 값과 색도(CIE L*a*b*), 그리고 닭고기 조직감의 연한 정도의 지표인 전단응력(Shear force)을 통해 관찰하였다. DBD-CPT 는 코팅한 닭가슴살에서 3.8 ± 0.3 log CFU/sample, 코팅하지 않은 닭가슴살에서 1.4 ± 0.4 log CFU/sample만큼의 Salmonella 저해를 보였고, 이를 통해 코팅으로 형성 된 평평한 표면이 DBD-CPT 의 Salmonella 저해 효과를 증진시켰음을 알 수 있었다. 그리고 반응표면 분석을 통해 결정된 Salmonella 저해에 대한 최적 CP 형성 전압과 처리 시간은 각각 38.9 kV와 3.6 min이었다. 최적 조건에서의 DBD-CPT 에 의해 Salmonella는 3.9 ± 0.4 log CFU/sample만큼 저해를 보였다. 한편 최적 조건에서의 DBD-CPT 는 TBARS 값, 색도, 그리고 전단 응력에 유의적인 영향을 주지 않았다. DBD-CPT 는 상업적 포장재에 포장되어 있는 조리 닭가슴살 큐브의 Salmonella 를 효과적으로 저해하였으며, 닭가슴살의 품질 특성에는 영향을 미치지 않았으므로 포장된 육류-즉석 섭취 식품의 효과적인 살균 방법으로 제안될 수 있다고 사료 되었다.

A few importers of marine products has practiced ice glazing of frozen fish and forced water injection into small octopus to increase their weight. These rampant practices have recently become a serious social issue. Therefore, this study was conducted to develop non-destructive detection methods for verifying forced water injected frozen small octopus using dielectric properties. The weight and dielectric properties of live small octopuses imported from China were measured using an electronic scale and dielectric probe connected with vector network analyzer, respectively. The frequency range from 0.5 to 4 GHz was used for measurement of dielectric properties of small octopus samples. The moisture contents of live small octopuses were determined by convection drying at 105°C for 24 h. To increase weight of small octopus samples, each sample was placed in a container including 2% polyphosphate solution of 800 mL and was kept for 24 h in a refrigerator. Then, the sample was removed from the solution and was frozen at -35°C for 24 h. The moisture contents of live small octopuses were 81.6 ± 1.9% (wb). Regardless of weight of live small octopuses, dielectric constant (ε′) and dielectric loss factor (ε′′) were from 76.09 to 58.62 and from 101.95 to 28.72, respectively. The average weight gain of small octopuses immersed in the solution was approximately 40.6%. Dielectric constant (ε′) and dielectric loss factor (ε′′) of forced water injected small were from 78.18 to 66.71 and from 51.96 to 25.05, respectively. In addition, there was a significant difference between dielectric properties and penetration depth of fresh frozen and forced water injected frozen small octopuses. The results clearly showed that dielectric properties of small octopuses affected by moisture contents could be an important factor to detect forced water injected frozen small octopuses.

탄산칼슘은 칼슘 보충제 및 식품 첨가물 등으로 식품산업에 널리 활용되고 있다. 산업 또는 환경 폐기물인 조개나 굴 껍데기인 개각과 산호 등은 천연 탄산칼슘 소재이므로 이를 식품, 의약 제품 등의 상품을 개발하는 것은 부가가치가 높은 산업적으로 의미가 큰 연구다. 하지만, 탄산칼슘은 물에 대한 낮은 용해도로 인해 생체 흡수성이 떨어지는 것이 문제점으로 알려져 있다. 따라서, 본 연구에서는 소성 가공한 후, 구연산을 첨가하여 용해도를 향상시킨 식용 가능한 패각 유래 칼슘 보충제를 개발하고자 하였다. 굴패각 유래 가공 시료로는 구리 패각을 미분 가공 후 550~1000°C에서 산화 소성을 거쳐 마그네슘을 첨가 후 400~1000°C에서 환원 소성한 시료(CS1, CaO 30%)와 이에 구연산을 첨가한 시료 (CS2) 두 가지를 준비하였고, 이들의 물리화학적 특성을 나노 레벨의 섬유상 탄산칼슘(CS3, CaO 40%)과 시중에 판매되고 있는 산호 유래 시판 칼슘 보조제인 코랄 칼슘(CS4)과 비교 분석하였다. 용해도 측정은 시료를 20°C에서 증류수 50 mL에 시료 0.1 g을 넣고 흔들어 방치한 후, 2.5 μm paper filter로 필터링 한 시료 10 mL과 증류수 10 mL의 무게 차이로 측정하였으며, 이를 100°C에서 12시간 동안 건조 후 측량한 시료의 무게로 확인하였다. 준비된 시료 중 CS3의 용해도(0.72 mg/g)가 가장 높았고 CS2 (0.42 mg/g), CS1 (0.5 mg/g), CS4 (0.06 mg/g)의 순으로 물에 잘 용해되지 않았다. 수산화칼슘이나 산화칼슘이 물에 용해되면 강염기를 나타내는 것으로 알려져 있는데, 관찰된 시료별 용해도의 차이가 pH에 영향이 있는지 확인하기 위해 용해된 용액의 pH를 측정하였다. 그 결과 CS1(12.5) CS2(12.4) CS3(9.5) CS4(8.8)의 순으로 높은 pH를 나타내어 용해도 차이로 인해 pH의 차이가 나타남을 알 수 있었다. 수산화칼슘의 경우, 수용액상 강염기를 나타내기 때문에 항균 능력이 있는 것으로 알려져 있으므로 용해도에 따라 그 항균력의 차이가 나타날 것으로 생각되어 시료별 항균성 실험을 진행하였다. LB 배지에 액체배양한 대장 균을 20 μm분주하여 도말해주고 그 위에 다시 각각의 시료를 분주하여 도말해서 48시간 배양한 결과 CS1, CS3에서는 항균성이 나타났지만 CS2, CS4에서는 항균성이 나타나지 않았다. 이와 같은 현상이 산화칼슘이 용해되어 수산화칼슘이나 탄산칼슘으로 변화되고, 또 결정의 구조 변화에 기인한 것인지 알아보기 위해 XRD를 이용하여 그 구조를 분석하였다. 그 결과, CS1, CS2는 CaCO3-Rhombohedral, CaO Lime-Cubic, 그리고 Ca(OH)2-Hexagonal 세 가지로 구성되어 있고 수산화칼슘의 비중이 CS2 보다 CS1에서 더 높았다. CS3는 CaCO3-Rhombohedral과 Ca(OH)2-Hexagonal 두 가지로 구성되었으며 대부분이 탄산칼슘으로 되어있다. CS4는 CaCO3-Rhombohedral의 단일 성분으로 구성되었다.

단백질과 사포닌 함량이 높은 해삼 열수 추출물을 첨가한 산성 음료는 응집, 침전 및 해삼 특유의 이취로 인하여 음료 제조에 많은 제한점이 있다. 단백질 클라우드 에멀션 음료 시스템은 고단백질 기능성 음료 제조 및 이취를 차폐할 수 있는 특성이 있고, 증점제로 사용되는 펙틴은 산성 조건에서 단백질과 콤플렉스를 형성함으로써 응집과 침전을 억제할 수 있다. 따라서 본 연구에서는 클라우드 에멀션 시스템에 해삼 열수 추출물 분말을 첨가하여 모델 음료를 제조하였으며 펙틴의 함량을 조절하면서 pH와 열처리 조건에 따른 모델 음료의 이화학적 특성을 관찰하였다. 해삼 열수 추출물 분말은 고온(121oC), 고압(15 psi) 조건에서 추출한 후 분무 건조하여 확보하였으며 단백질, 다당, 회분, 수분함량은 각각 43.46, 44.97, 5.38, 4.19%이었다. 모델 음료는 올리브유(0.1%), 해삼 열수 추출물 분말(2%), 유청 단백질(2%), 펙틴(0.01-2%)을 혼합한 후 고압 균질기(4500 psi)를 이용하여 균질화하였다. 제조한 클라우드 에멀션 모델 음료는 30oC와 85oC에서 각각 2 또는 30 min 동안 열처리를 하였다. 펙틴, 유청 단백질의 ξ-potential과 입자크기는 pH를 7에서 3으로 감소시킴에 따라서 증가하였다. 펙틴을 0.01%에서 2% 범위로 첨가한 모델 음료의 ξ-potential과 입자크기는 펙틴함량의 증가에 따라서 증가하였다. 저농도의 펙틴(0.01-0.1%)을 첨가한 경우에는 응집과 상분리 현상이 발생하지 않았다. 그러나 고농도 펙틴(0.5-2.0%)의 첨가, pH를 7에서 3으로 감소 및 85oC에서 30 min 동안의 열처리 조건에서는 complex coacervation에 의한 응집과 상분리 현상이 발생하였다.

The effects of high hydrostatic pressure (HHP) or concentration treatment or sodium hydrogen carbonate addition on microbial and quality properties of cold drip liquid coffee were investigated during storage at room temperature. Cold drip liquid coffee was determined to pH, acidity, general bacteria, and Y&M (Yeast and Molds) according to HHP treatment or adding 0.2% sodium hydrogen carbonate for 40 days storage at 20°C. Also, an equivalent mixture of concentrated coffee and cold drip liquid coffee or liquid coffee with 0.2% sodium hydrogen carbonate was used for determining the sensory evaluation, due-trio and preference test. The cold drip liquid coffee with 0.2% sodium hydrogen carbonate had higher pH and lower titratable acidity than the control during 40 days storage at 20°C. Total viable cell and Y&M counts of cold drip liquid coffee added with 0.2% sodium hydrogen carbonate or treated by HHP at 300 MPa for 25 min were lower than the control during storage at 20°C. The result of the due-trio and preference tests shows that there was no significant difference between cold drip liquid coffee added to 0.2% sodium hydrogen carbonate and the control or between the equivalent mixture of concentrated coffee with cold drip liquid coffee and the control. As a results, Cold drip liquid coffee treated by HHP, concentrated by evaporation, and added to sodium hydrogen carbonate has a potential to extend a shelf life at ambient temperature storage.

The purpose of this study was to compare hand washing awareness and microorganism contamination on the hands for evaluating the difference between awareness and conditions of hand hygiene. The average number of total aerobic bacteria and coliform was 2.7 log CFU/hand and 1.8 log CFU/hand, respectively. Coliform bacteria were detected in all of the students tested in this study. The questionnaire survey data obtained via a direct interview were collected from 100 university students with microorganism analysis. A majority (90%) of the students recognized that good hand hygiene is important in order to prevent food poisoning. In the hand washing survey data, the responses suggesting “always washed” from “before eating food”, “after handling money”, “after finishing study” and “after visiting patients” were observed in 18, 13, 15 and 33 out of the 100 students, respectively. The questionnaire data of hand washing frequency and time duration showed that 14 students and 6 students answered “more than 8 times of hand washing per day” and “more than 30 seconds of hand washing time”, respectively. These results indicated that improper hand washing practices and poor hand hygiene were identified in the majority of the students. This emphasizes the difference between awareness and conditions of hand hygiene. Repeated hand washing education about the frequency, time duration and methods is constantly required to improve hand hygiene. Installation of hand washing equipment in the space of a restaurant and cafeteria is suggested for enhancing hand hygiene before eating food.

Ochratoxin A, which is frequently detected in cereals and infant diets worldwidely, is a mycotoxin to damage mainly the kidney and liver. Because ochratoxin A is highly thermostable compound. it is necessary to study ways of reducing level of ochratoxin A by controling processing steps. However, food processes, including extrusion, expansion, roasting, and steam cooking, which are used in order to mitigate the contents of ochratoxin A, are known to produce polycyclic aromatic hydrocarbons, which are generated from radicals decomposed by pyrolysis. Therefore, this study analyzed the levels of 4 polycyclic aromatic hydrocarbons, benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based products made in high pressure and heating process. Rice samples were finely ground, and homogenized samples were alkaline treatement with 1 M KOH/EtOH and extracted with liquid-liquid extraction method using n-hexane. The extracted solution was pretreated with a silica cartridge. The purified solution was dried with nitrogen gas and dissolved in 1 mL of dichloromethane and injected into GC/MSD. We had overall recoveries for 4 polycyclic aromatic hydrocarbons spiked into rice samples ranging from 92.8 to 110.2%. The limit of quantitations of benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based product were 0.19 ng/g, 0.38 ng/g, 0.51 ng/g, and 0.31 ng/g, respectively. However, these 4 polycyclic aromatic hydrocarbons in all processed rice samples were not detected.

방울토마토는 냉·한대 지역을 제외하고는 세계적으로 생산 및 소비되는 채소로 수확 후 품질관리 등에 대한 연구가 많이 이루어지고 있다. 본 연구에서는 비파괴 측정 방법들 중 하나인 자기공명영상(Magnetic Resonance Imaging, MRI)기술을 활용하여 방울토마토의 품종 및 성숙단계별 과실 내부 구조의 변화를 비교하였다. 공시재료는 방울토마토 3품종(티아라, 티아라_TY, 유니콘)에 대하여 성숙단계를 과피색을 기준으로 6단계로 세분화하고 3반복으로 MRI 영상을 획득하였다. 실험은 전북대학교 부설 농업기계 ICT 융합 연구소가 보유하고 있는 MRI 시스템을 활용하여 이미지를 얻었다. 자기공명영상 이미지는 Gradient Echo 펄스열을 사용하였고, 횡단면(Axial)의 영상면(Image Direction)을 중심으로 영상영역(Field of View, FOV)은 50 mm x 50 mm로 1회 촬영할 때마다 20개의 영상들을 얻었다. 촬영하여 얻은 영상들과 직접적으로 비교하기 위해 영상면과 같은 방향으로 임의적으로 방울토마토의 중간을 칼로 잘라 비교하였다. 촬영과 실제 잘라 내부를 비교해본 결과, 방울토마토 내부 심실의 수는 다른 품종들에 비해 티아라 품종이 가장 많았다. 생육단계별로는 3품종 모두 마지막 단계(Red Stage)의 중과피의 형태가 뚜렷하게 구분되지 않았으며, 특히 유니콘품종의 경우 다른 품종들에 비해 더 빠르게 모호해지는 것을 알 수 있었다. 또한 유니콘 품종의 경우, 다른 두 품종에 비해 미숙단계인 1,2단계(Green Stage, Breaker Stage)에서 중과피의 형태가 빠르게 발달하는 것이 확인되었다. 본 연구를 통하여, 방울토마토와 같이 성숙단계별 내부 변화가 크게 일어나는 과실에 대하여 비파괴 자기공명영상으로 분석함으로써 재배 환경조건에 따른 품종별 내부 생리장해 및 형태의 신속한 변화 탐지에 효율적으로 활용될 수 있는 가능성을 확인하였다.