• Title/Summary/Keyword: storage quality

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Development of Analytical Reference Material for Proficiency Test of Pesticide Multi-residue Analysis in Green-pepper (풋고추 농약다성분분석 정도관리용 분석표준물질 개발)

  • Kim, Jong-Hwan;Choi, Sung-Gil;Oh, Young-Gon;Kwon, Young-Sang;Hong, Su-Myeong;Sung, Mun-Hyun;Lee, Se-Ja;Hwang, Sun-Young;Seo, Jong-Su
    • The Korean Journal of Pesticide Science
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    • v.20 no.3
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    • pp.211-220
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    • 2016
  • This study was to develop the analytical reference material of green-pepper for multi-residue analysis of pesticides. According to the ISO Guide 35, ISO Guide 13528 and EURL-PT protocol, the homogeneity, stability, assigned value and uncertainty were calculated to assess if it was suitable to be used as the proficiency test or quality control. The values of the within-bottle standard variation ($s_{wb}$) and the between-bottle standard variation ($s_{bb}$) were 1.7~3.7% of assigned value according to the requirement of the ISO guide 35. And, the uncertainty ($u^*{_{bb}}$) due to inhomogeneity was 0.8~1.1% for all pesticides. The storage stabilities of ten-pesticides at various conditions were assessed. For all target pesticides, the slop ($b_1$) values were smaller than the corresponding values of $[t_{0.95,n-2}{\times}s(b_1)]$ specified by the ISO guide 35, indicating that there were no statistically significant decreases in the concentration of the target pesticides when the analytical reference material was stored at room temperature ($20{\sim}30^{\circ}C$) for 7 days, freezing ($-20^{\circ}C$) for 30 days and deep freezer ($-80^{\circ}C$. except for bifenthrin, fenpropathrin) for 245 days. For proficiency test by using it developed by Korea Institute of Toxicology, inter-lab test was performed with eight organization performing the residual pesticide analysis. We found that there were some different results among them. Some were assessed as questionable or unacceptable for two pesticides and one organization didn't analyze the six pesticides. From these results, this green-pepper analytical reference material containing ten-pesticides could be used as a tool for the proficiency test to improve the reliability or consistency for pesticide residue's results.

Studies on the Packaging and Preservation of Kimchi (우리나라 김치의 포장과 저장방법에 관한 연구)

  • Lee, Yang-Hee;Yang, Ick-Whan
    • Applied Biological Chemistry
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    • v.13 no.3
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    • pp.207-218
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    • 1970
  • Studies were carried out to develope the most economical and practical methods of packaging and preservation of kimchi, so commercialization of kimchi manufacture could proceed rapidly. The results obtained may be summarized as following. (1) It is generally established that the acceptable range of lactic acid content of kimchi is between 0.4% and 0.75%. Based on sensory evaluation, kimchi having lactic acid content below 0.4% and above 0.75% was not edible, and the time of optimum taste corresponded to the vicinity of 0.5% of lactic acid content. For the refrigeration storage with or without preservatives, the packaging kimchi in plastic film must be done at the lactic acid content of 0.45%, for lactic acid fermentation will continue slowly after the packaging. However, for the heat sterilized kimchi the packaging should be done at the 0.5% of lactic acid content for the best because lactic acid fermentation is completely stopped after the packaging. (2) Polyethylene, polypropylene, and polycello were chosen as suitable packaging materials. Polyethylene is cheapest among them but kimchi packaged in this film was damaged frequently in handling process and gave off kimchi flavor. On the other hand polypropylene also gave off kimchi flavor, but its higher mechanical strength gave better protection to kimchi and it had superior display effect due to the transparancy. Therefore polypropylene made much better packaging material. Polycello proved to be the best packaging material from the standpoint of physical characteristics but its price is higher than that of other plastic films. To be effective, the thickness of plastic films for packaging kimchi must exceed 0.08mm. (3) Keeping property of kimchi appeared to be excellent by means of freezing. However, by the time the frozen kimchi was thawed out at room temperature, moisture loss due to drip was extensive, rendering the kimchi too stringy. (4) Preservation of kimchi at refrigerated temperatures proved to be the best method and under the refrigerated condition the kimchi remained fresh as long as 3 months. The best results were obtained when kimchi was held at $0^{\circ}C$. (5) In general, preservatives alone were not too elective in preserving kimchi. Among them potassium sorbate appeared to be most effective with the four fold extension of self-life at $20^{\circ}C$ and two fold extension at $30^{\circ}C$. (6) In heat sterilization the thickness of packaged kimchi product had a geat effect upon the rate of heat penetration. When the thickness ranged from 1.5 to 1.8cm, the kimchi in such package could be sterilized at $65^{\circ}C$ for 20 minutes. Kimchi so heat treated could be kept at room temperature as long as one month without apparent changes in quality. (7) Among combination methods, preservation at refrigerated and heat sterilization could be favorably combined. When kimchi was stored at $4^{\circ}C$ after being sterilized at $65^{\circ}C$ for 20 minutes, it was possible to preserve the kimchi for more than 4 months.

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Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2010 (설비공학 분야의 최근 연구 동향 : 2010년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwa-Taik;Lee, Dae-Young;Kim, Seo-Young;Choi, Jong-Min;Kim, Su-Min;Kwon, Young-Chul;Baik, Yong-Kyu
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.6
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    • pp.449-469
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    • 2011
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering during 2010. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery, and new and renewable energy. Various topics were presented in the field of general thermal and fluid flow. Research issues mainly focused on the thermal reliability of axial fan and compressor in the field of fluid machinery. Studies on the design of ground source heat pump systems and solar chemical reactors were executed in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (3) Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and CO2 were studied. Performance improvement of refrigeration systems are tried applying various ideas of refrigerant subcooling, dual evaporator with hot gas bypass control and feedforward control. The hybrid solar systems combining the solar collection devices with absorption chillers or compression heat pumps are simulated and studied experimentally as well to improve the understanding and the feasibility for actual applications. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. Various studies on heating and cooling systems, HVAC facilities, indoor air environments and energy resources were carried to improve the maintenance and management of building service equipments. In the field of heating and cooling systems, papers on a transformer cooling system, a combined heat and power, a slab thermal storage and a heat pump were reported. In the field of HVAC facilities, papers on a cooling load, an ondol and a drying were presented. Also, studies on HVAC systems using unutilized indoor air environments and energy resources such as air curtains, bioviolence, cleanrooms, ventilation, district heating, landfill gas were studied. (5) In the field of architectural environment and energy, studies of various purposes were conducted such as indoor environment, building energy, renewable energy and green building. In particular, renewable energy and building energy-related researches have mainly been studied reflecting the global interest. In addition, many researches which related the domestic green building certification of school building were performed to improve the indoor environment of school.

Effects of freezing temperature on the physiological activities of garlic extracts (냉동 온도에 따른 마늘 추출물의 생리활성 변화)

  • Park, Jong Woo;Kim, Jinse;Park, Seok Ho;Choi, Dong Soo;Choi, Seung Ryul;Oh, Sungsik;Kim, Yong Hoon;Yoo, Seon Mi;Han, Gui Jeung
    • Food Science and Preservation
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    • v.22 no.4
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    • pp.520-527
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    • 2015
  • This study investigated the physiological activities of garlic extracts frozen at -20, -80, and $-196^{\circ}C$. To determine the optimum freezing temperature for maintaining garlic's physiological activity, antioxidant and antibacterial activities were investigated. The antioxidant activities were determined by DPPH radical scavenging ability, SOD-like activity, nitrite-scavenging ability, and reducing power. Total phenolic compounds and flavonoids of garlic extract frozen at $4^{\circ}C$ (control) were measured as $6.91{\pm}0.69{\mu}gGAE/g$ and $0.315{\pm}0.017{\mu}gQE/g$, respectively. Although the content of total phenolic compounds was not affected by the different freezing temperatures, the flavonoids contents of garlic extract frozen at $-20^{\circ}C$ were slightly decreased. The DPPH radical scavenging ability of garlic extracts (2 mg/mL) frozen at $-80^{\circ}C$ was 61%, whereas those frozen at $-20^{\circ}C$ and $-196^{\circ}C$ were 51%. SOD-like activity was slightly increased by freezing. However, the nitrite scavenging ability (18% at pH 3.0) and reducing power (OD700=1.6) were not affected by freezing temperatures. Antimicrobial activities did not show significant differences depending on freezing temperatures. Taken together, the physiological activities of the frozen garlic extracts were not significantly changed by the freezing temperatures; however, the antioxidant and antibacterial effects of the phenolic compounds and flavonoids were maintained at $-80^{\circ}C$. These results suggest that $-80^{\circ}C$ frozen garlic could maintain a higher quality than the conventional freezing method ($-20^{\circ}C$) without loss of physiological activities during the storage.

Properties of Baechu Kimchi treated with Black Rice Water Extract (흑미를 첨가하여 항산화성이 강화된 배추김치의 개발 및 품질 특성)

  • Mo, Eun-Kyoung;Kim, Seung-Mi;Yang, Sun-A;JeGal, Sung-A;Choi, Young-Sim;Ly, Sun-Yung;Sung, Chang-Keun
    • Food Science and Preservation
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    • v.17 no.1
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    • pp.50-57
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    • 2010
  • To develop a new functional kimchi with antioxidative properties, salted baechu was soaked in black rice water extract for 6 h at room temperature. The antioxidative property of the water extract was $78.75{\pm}1.18%$ that of the control (0.1% [w/v] alpha-tocopherol). The black rice gel was added to the baechu kimchi preparation. The color of baechu kimchi treated with black rice water extract changed to dark violet and/or black. Control kimchi and black rice water-treated kimchi were stored at $4^{\circ}C$ for 30 days. No significant differences were detected between the control and the black rice water-treated group in the early stages of fermentation. As fermentation time increased, pH decreased and titratable acidity increased rapidly in control kimchi. However, such marked changes were not evident in test kimchi. The hardness value of black rice water-treated kimchi was higher than that of control kimchi after the midpoint of the fermentation period. The storage life of baechu kimchi treated with black rice water extract was prolonged by up to 5 days compared with control samples, owing to a decline in lactic acid bacteria and yeast levels during the final fermentation period in black rice water-treated kimchi. The total phenolic levels and the antioxidative capacity of black rice water-treated kimchi (83%) were approximately 1.5-fold higher than in control kimchi (57%). In sensory evaluation, black rice water-treated kimchi scored higher than did control kimchi using a blind test protocol.

Effect of Chitosan Treatment on the Quality of Dried Lavers (건조김 제조시 키토산처리가 품질에 미치는 영향)

  • Park, Jeong-Wook;Kang, Seong-Gook;Oho, Si-Won;Park, Sun-Young;Jung, Soon-Teck;Park, Yang-Kyun;Rhim, Jong-Whan;Ham, Kyung-Sik
    • Korean Journal of Food Science and Technology
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    • v.31 no.4
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    • pp.1115-1119
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    • 1999
  • Chitosan was used to treat lavers during the production of dried lavers. In the procedure of washing the harvested lavers, the lavers were treated with various solutions of 0.1 and 0.01% of 30 cp chitosan and of 0.005 and 0.04% of 90 cp chitosan. Then treated lavers were processed as usual for the production of dried lavers. Significant differences between chitosan-treated and non-treated lavers were observed in flavor, in total microbial counts, and in the number of coliform microorganisms. Off-flavor of dried lavers was reduced significantly by treating with chitosan. Total microbial count was $3.7{\times}10^{4}$ cells/g in the non-treated dried lavers, but they were $5.7{\times}10^{3}$ cells/g and $2.1{\times}10^{3}$ cells/g, respectively, in the dried lavers treated with 0.01% and 0.1% of 30 cp chitosan. The number of coliform microorganisms was 240 cells/g in non-treated dried lavers. However, coliform microorganisms were not detected in the dried lavers treated with 0.1% of 30 cp chitosan. When the dried lavers were used to make Kimbab (rice rolled with laver), the number of total microorganisms increased very slowly during storage time at $20^{\circ}C$ in the Kimbab rolled with chitosan-treated dried lavers compared to that in the Kimbab rolled with non-treated dried lavers.

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SUITABILITY OF SHELLFISHES FOR PROCESSING 1. Suitability of Baby Clam for Processing (패류의 가공적성 1. 바지락의 가공적성)

  • LEE Eung-Ho;PYEUN Jae-Hyeung;KIM Soo-Hyeun;CHUNG Seung-Yong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.8 no.1
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    • pp.20-30
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    • 1975
  • It is matter of fact processing technology must affects the quality and yield of final product and these also depend on the selection of raw material directly or indirectly. So that the estimation of tile preprocessing condition of shellfish is of great importance for distributors and processors. This study was attempted to establish the basic data for evaluating the processing suitability of baby clam, which is one of the five important shellfishes for domestic use and export. The important results are as follows: 1. The ratio of meat volume and meat weight to the holding capacity by shells may be useful for measuring the condition index of baby clams. 2. Baby clams grown in the beds with the composition of a large quantity of gravel were low in condition index value than in sand and mud. 3. If the green feed phenomenon was the prime consideration for canned baby clams, tile most suitable harvest season if October. In this period, the digestive tract in body was almost colorless. 4. As a whole, seasonal changes of moisture and fat content in baby clams were reversely correlated. Protein content increased from April and slightly decreased for a while from July to August and increased again from September. In March, the content of glycogen was 6.3 to 6.8 percent. From this period to October, glycogen was rapidly decreased. In October, it was only 0.1 to 0.2 percent but increased from November. There were little seasonal changes in pH value and crude ash content. The pH value of meat was 6.0 to 6.2 and crude ash content was about 2 percent. 5. By the results of condition index and chemical composition of baby clams, the suitable harvest season as raw materials for processing was from March to June and from September to October. 6. The steamed baby clam meat was packed with 2 percent salt solution containing 0.15 percent, citric acid or 0.5 percent $Na_2$ EDTA in a round sanitary tin can coated with C-enamel that is 203.9 ml by volume and sterilized for 60 minutes at $112^{\circ}C$. The canned product has shown a good result to reserve the natural characteristics of baby clam through six month storage at room temperature.

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Improved Acroparesthesia During Enzyme Replacement Therapy in a Patient Lately Diagnosed with Fabry Disease (진단이 지연된 Fabry 병 환자에서 효소대체요법을 통한 사지 말단 동통의 호전을 보인 1례)

  • Yang, Aram;Kim, Jinsup;Cho, Sung Yoon;Jin, Dong-Kyu
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.17 no.3
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    • pp.92-95
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    • 2017
  • Fabry disease (FD) is an X-linked lysosomal storage disorder caused by an ${\alpha}$-galactosidase A (GLA, MIM 300644) enzyme deficiency due to pathogenic variants in the ${\alpha}$-galactosidase A gene (GLA). The disease leads to accumulation of globotriaosylceramide (Gb3) and related glycophospholipids affecting nearly all major organ systems, with the primary sites damaged by Gb3 including renal glomeruli, myocardium, neurons of the dorsal ganglion and autonomic nervous system, and vascular endothelial and smooth muscle. Progressive deposition in these organ systems present with various clinical manifestations including acroparesthesia, renal failure and heart failure. Here, we report a Chinese male diagnosed with Fabry disease in his late $4^{th}$ decades showing improvement of acroparesthesia during enzyme replacement therapy (ERT). A 48-year-old Chinese man who presented with chronic recurrent severe burning pain in his fingers and toes since the age of 10, with worse involvement of the former visited to our clinic for further evaluation. His medical history included a transient ischemic attack aged 40 and diagnosed with stage 4-5 chronic kidney disease aged 47. In the family history, the patient's brother was found to be have Fabry disease 1 month before his visit. Except for his brother, all other members of the family are healthy. Based on his medical history and family history, he was strongly suspicious for Fabry disease. He was found to have a galactose-alpha-1,3-galactose level 4.96 (Reference range, 42.5-67.9) suggestive of Fabry disease. The followed sequencing of GLA coding region in our patient revealed hemizyosity for the mutation c.988C>T (Q330X) in Exon 7. Since ERT start, he showed significant improvement in his symptoms of burning sensation of fingers and toes. On the contrary, due to deteriorating kidney function even with ERT, he is considered for kidney transplantation. Despite of diagnostic delay until late 4th decades, ERT showed a potential improvement of acroparesthesia in our patient. However, late start of ERT can lead to poor outcome in multiorgan function. Therefore, early diagnosis with high index of suspicion followed by continuous ERT with regular monitoring have an impact on quality of life in Fabry disease.

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Investigation on the Safety of Hydroquinone and Preservatives among Whitening Functional Cosmetics Containing Albutin in Korea (국내 유통 알부틴 함유 미백 기능성화장품 중 히드로퀴논 및 살균보존제 안전성 조사)

  • Cho, Joong Hee;Kim, Ji Hyeung;Eom, Sun Ah;Kang, Min Jeong;Han, Young Sun;Hur, Myong Je
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.45 no.4
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    • pp.399-408
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    • 2019
  • Arbutin, which is used as a whitening ingredient, can produce hydroquinone, known as causing skin disease and carcinogen. Preservatives are essential to prevent microbial contamination during long-term storage and use of cosmetics, but safety issues such as toxicity and skin irritation are being raised. This study was conducted to determine hydroquinone and 21 preservatives levels in 40 arbutin-containing whitening functional cosmetics sold on-line and off-line. Result showed that 9 products contained hydroquinone. The concentrations in 7 products were ranged from 0.3 to 0.9 ppm, which were within the maximum allowed amount established by the Ministry of Food and Drug Safety. However, 2 products were 8.4 and 50.5 ppm and exceeded the allowed amount. Preservatives were detected 20 products. Detected items and ranges were phenoxy ethanol 0.1 ~ 0.7% (N = 15), Methyl paraben 0.19 ~ 0.21% (N = 2), Chlorphenesin 0.13% (N = 1), chlorhexidine 0.006% (N = 1), Propyl paraben 0.06% (N = 1), which were within maximum allowed amount established by the Ministry of Food and Drug Safety. Also, in cases of functional cosmetics the phrase "functional cosmetics" should be expressed on the primary or secondary package of cosmetics by cosmetics act. However, 1 product did not state the phrase as functional cosmetics. This study suggest that preservatives were safely managed. However, hydroquinone in hydroquinone-detected products could be produced by the decomposition of arbutin. Thus, further studies on the decomposition of arbutin are required to improve the quality control of the cosmetics.

Effects of Gamma Irradiation and Ethylene Oxide Fumigation for the Quality Preservation of Spices and Dry Vegetables (건조향신 조미식품의 품질보존을 위한 효과적인 살균방법에 관한 비교연구)

  • 신광순;마점술;조종후
    • Journal of Food Hygiene and Safety
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    • v.4 no.2
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    • pp.119-132
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    • 1989
  • Gamma irradiation as a new physical treatment was applied to comparative investigates with a conventional ethylene oxide fumigant on the microbiological and physicochemical qualities of selected spices and dry vegetables such as powdered red pepper, black pepper, welsh onion, onion, garlic, carrot, korean cabbage and instant ramyon soup. The microorganisms contaminated in the sample, including total viable count, thermophilic bacteria, aerobic spore and fungi counts between the $10^4\;to\;10^6/g$ range. Coliforms were found only in black pepper and welsh onion powder as the $10^2\;to\;10^3/g$ level. A radiation dose of 7 to 10 KGy were sterilized completely to the contaminated microorganisms, while ehthylene oxide (E.O.) fumigation reduced of them to the $10^3/g$ level. An optimum dose of irradiation was less detrimental than E.O. fumigation to the physicochemical properties of the sample. Sensory evaluation after three months of storage at room temperatures showed that the overall acceptability of irradiated sample was higher than that of the non treated control as well as E.O. fumigated samples. Comparison gamma irradiation with E.O. gas treatment showed that E.O. treatment was less effective than radiation in cotrolling microbial contamination of spices and vegetables.

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