• Title/Summary/Keyword: washing and heat treatment

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Effects of Cooking and Processing on the Reduction of Aflatoxin Content in Corn (옥수수의 조리 및 가공이 Aflatoxin 감소에 미치는 영향)

  • 여현종;김종규
    • Journal of Food Hygiene and Safety
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    • v.18 no.2
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    • pp.87-93
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    • 2003
  • This study was performed to investigate aflatoxin reduction resulting from the pre-treatment and the cooking and processing of corn. Aflatoxin was produced by Aspergillus parasiticus ATCC 15517 on a type of corn imported from the United States. The aflatoxin-produced com (AC) was pre-treated in three ways in order to reduce aflatoxin: exposure to sun light for 7 days (SC); ultraviolet irradiation for 56 hours (UC); and washing with water three times (WC). Four kinds of cooking and processing methods (boiling, steaming, baking, and popping) were used to reduce aflatoxin in the AC control, SC, UC, and WC. These treatments produced com gruel, com cakes, com bread and popcorn. The aflatoxin content in the samples was determined by high performance liquid chromatography. The total aflatoxin level of the AC was significantly decreased by sun light and UV (p<0.05), and decreased by washing. After cooking and processing the AC, SC, UC, and WC, and averaging the total aflatoxin levels in the final products, the greatest reduction was found in the com gruel, then the popcorn, then the corn cakes, and the least reduction in the com bread. These results indicate that sunlight and ultraviolet energy could be effective factors in aflatokin degradation in corn before cooking and processing. This study also indicates that boiling, steaming, baking and popping were helpful in reducing the aflatoxin level in the com and that the most helpful factors were exposure time to heat. More research is needed to reduce the aflatoxin level down to below the maximum tolerable level of aflatoxin in foods.

Fabrication of Cr$_2$O$_3$powder from waste MgO-Cr refractory

  • Lee, Hoon-Ha;Sohn, Jin-Gun;Lee, Jae-Young;Kim, Dae-Young
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.357-361
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    • 2001
  • The possibility of producing Cr$_2$O$_3$powder from waste magnesia-chromium refractory was investigated by sulfuric acid reaction, alkali fusion, water leaching & purification and heat treatment. The effects of temperature, the amount of NaOH added and the flow rate of air on chromium extraction efficiency in an alkali fusion step were investigated. The fusion product was leached with methanol to solve free-NaOH, and then leached with water to produce a Na$_2$CrO$_4$solution. The purity of chrome(Ⅵ) oxides, prepared both from monochromate with an impurity content and monochromate purified with $CO_2$were also examined. The purified monochromate solution was reduced from Cr(Ⅵ) to Cr(III) with NaHSO$_3$solution. The reduced solution was neutralized with NaOH to produce Cr(OH)$_3$. Water washing was treated to eliminate Na$_2$SO$_4$from neutralized Cr(OH)$_3$slurry. The washed Cr(OH)$_3$was dried and thermally treated to produce Cr$_2$O$_3$powder. The properties like lightness and hue of Cr$_2$O$_3$fabricated in this study were L=47.47, a=-14.40 and b=17.21.

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Preparation and Characterization of Dense Suspension of Aloe Gel Microcapsule (알로에 겔 마이크로캡슐의 고농도 현탁액의 제조 및 특성)

  • Go, Nam Kyung;Lee, Jin Sil;Lee, Shin Young;Hur, Won
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.1
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    • pp.47-54
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    • 2013
  • Aloe gel microcapsule was prepared by dehydrating dispersed aloe gel droplets in the form of W/O emulsion using a vacuum evaporator. The microcapsules remained in stable suspensions after washing with mineral oil and had a homogeneous spherical structure with diameter less than 6.4 ${\mu}m$. The microcapsule suspension in mineral oil (> 41%) exhibited a step increase in viscosity and shear-thinning but not showed thixotropic behavior with a yield stress higher than 300 Pa. The dense suspension appeared to be semi-solid as the microcapsule fraction increases and to be stable after heat treatment at $105^{\circ}C$ for 15 min. In conclusion, the dense suspension composed of gel microcapsules is expected to provide a basic cosmetic formulation that can be applied to develop various types of aloe gel cosmetic products.

A Study on the Cellulose Blend Knit Fabrics using Burn-out Printing Convergence Technology (셀룰로오스 혼방 니트 편포의 착색번아웃 날염복합기술에 관한 연구)

  • Cho, Ho-Hyun;Chung, Myung-Hee;Lee, Jong-Lyel
    • Journal of the Korea Fashion and Costume Design Association
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    • v.16 no.4
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    • pp.229-235
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    • 2014
  • This study conducted a research on burn-out printing convergence technology for cellulose blend knit fabrics. Printing technology, which forms color pattern on the fabric, can be generally classified into four according to printer or printing method, e.g. screen printing, roller printing, rotary printing, digital printing. However, these printing methods are flat in design or pattern, which have limitation to overcome monotonousness of fabric, so that recently burn-out process method, which expresses three-dimensional pattern effect by treating chemical on the surface of fabric as the method to appeal its esthetics to the customers. Particularly, in case of cellulose/polyester composite material, first, it is proceeded in 2 processes, by dyeing cellulose or polyester fabric and burning out cellulose fabric, in this process, due to pollution caused by disperse dye migration, color of polyester fabric part could be discolored, which has high falt risk. This research considered coloring burn-out technique, which simultaneously proceed dyeing and burn-out by reducing dyeing and burn-out process to 1 stage, which were proceeded in 2 stages previously. As the research result, it was confirmed that reasonable depth of roller was 0.04~0.06mm in roller printing process, heat treatment condition of burn-out far-infrared radiation was $185^{\circ}C{\times}30m/min$. Color fastness to washing was confirmed to be 4-5 grade, color fastness to rubbing, 3-4 grade, color fastness to light, 4 grade. Also, it was confirmed that energy reduction effect appeared 38.19%, in case of energy cost per yard compared to the existing production, also, 19.74%, in case of production cost.

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Growth characteristics of pathogens isolated from surface of carcass (도체표면에서 분리한 병원성 미생물의 성장특성)

  • 정영숙;박나영;이신호
    • Food Science and Preservation
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    • v.9 no.4
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    • pp.434-440
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    • 2002
  • The growth characteristics of 5. coli O157:H7 CDFI, A. sobria CDF3 and S. aureus CDF2 isolated from surface of carcass were investigated to improve hygienic quality of beef. The total count of carcass surface before washing was higher than that of after washing. Total count of after cooling decreased about 10$^1$∼ 10$^2$/㎠ compare with before cooling. Total count of carcass surface after transfer increased regardless seasons. The growth E. coli O157:H7 CDF1 occurred at pH 4 and 6% NaCl but A. sobria CDF3 and S. aureus CDF2 did not grow at the same conditions. Although the growth of E. coli O157:H7 CDF1 and S. aureus CDF2 was inhibited by 0.3% lactic acid, but A sobria CDF3 did not grow in TSB containing 0.3% lactic acid. E. coli O157:H7 CDF1 grew rapidly after 3 days incubation at 10$\^{C}$ but did not grow at 4$\^{C}$. But A. sobria CDF3 grew rapidly after 3 days incubation at 4$\^{C}$. E. coli O157:H7 CDF1 and A. sobria CDF3 were destroyed by heat treatment for 3 min at 60$\^{C}$. S. aureus CDF2 did not detect after heat treatment for 2 min at 70$\^{C}$.

Antioxidant Activity and Physicochemical Characteristics of Pimpinella brachycarpa Nakai with Treatments Methods (처리 방법에 따른 참나물의 이화학적 특성 및 항산화 활성)

  • Chae, Hyun Suk;Lee, Sang Hoon;Jeong, Heon Sang;Kim, Woon Ju
    • The Korean Journal of Food And Nutrition
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    • v.26 no.1
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    • pp.125-131
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    • 2013
  • This study was carried out to evaluate the physicochemical characteristics of Pimpinella brachycarpa Nakai with treatments methods. Pimpinella brachycarpa Nakai was prepared with washing, blanching, and steaming. Pimpinella brachycarpa Nakai samples were analysed proximate compositions, ${\beta}$-carotene, folic acid, minerals, polyphenol and flavonoid content, and antioxidant activity. Crude protein, lipid, ash and fiber content of raw Pimpinella brachycarpa Nakai were 24.43, 9.02, 17.74, and 33.50%, respectively. pH ranged from 6.49 in blanched Pimpinella brachycarpa Nakai to 5.99 in steamed Pimpinella brachycarpa Nakai. The Hunter L value was decreased with heat treatment and a- value showed that the green color was higher in steamed Pimpinella brachycarpa Nakai. ${\beta}$-Carotene content was increased to 18% in washed Pimpinella brachycarpa Nakai, 54% in blanched Pimpinella brachycarpa Nakai, and 10% in steamed Pimpinella brachycarpa Nakai. Folic acid content of washed, raw, steamed, and blanched Pimpinella brachycarpa Nakai were 848.87, 772.16, 271.54, and 260.74 mg/100 g, respectively. Major minerals were K, Ca, Na, and Mg, and K content had the highest value of 93.13~244.38 mg/100 g with treatment. Total polyphenol and flavonoid content, and antioxidant activity were higher in the order of blanched, steamed, washed, and raw Pimpinella brachycarpa Nakai.

Practical Usage of Low-Temperature Metal Catalyst for the Destruction of Volatile Organic Compounds (VOCs) (휘발성 유기화합물(VOCs) 제거를 위한 저온금속촉매 실용화에 관한 연구)

  • Jung, Sung-Chul;Lee, Seung-Hwan
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.6
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    • pp.397-405
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    • 2012
  • In this study, performance evaluation of newly developed technology for the economical and safe removal of volatile organic compounds (VOCs) coming out from electronic devices washing operation and offensive odor induction materials was made. Metal oxidization catalyst has shown 50% of removal efficiency at the temperature of $220^{\circ}C$. Composite metal oxidization catalyst applied in this study has shown that the actual catalysis has started at the temperature of $100^{\circ}C$. Comprehensive analysis on the catalyst property using Mn-Cu metal oxidization catalyst in the pilot-scale unit was made and the removal efficiency was variable with temperature and space velocity. Full-scale unit developed based on the pilot-scale unit operation has shown 95% of removal efficiency at the temperature of $160^{\circ}C$. Optimum elimination effective rates for the space velocity was found to be $6,000hr^{-1}$. The most appropriate processing treatment range for the inflow concentration of VOCs was between 200 ppm to 4,000 ppm. Catalyst control temperature showed high destruction efficiency at $150{\sim}200^{\circ}C$ degrees Celsius in 90~99%. External heat source was not necessary due to the self-heat reaction incase of VOCs inflow concentration is more than 1,000 ppm. Equipment and fuel costs compared to the conventional RTO/RCO method can be reduced by 50% and 75% respectively. And it was checked when there was poisoning for sulfide and acid gas.

Evaluation of the HACCP System on Microbiological Hazard during Dressing Production (드레싱 제조업체의 HACCP 시스템 적용을 위한 미생물학적 위해도 평가)

  • Kwon, Sang-Chul
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.3
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    • pp.457-463
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    • 2013
  • The purpose of this study was to apply the Hazard Analysis Critical Control Point (HACCP) system to the production of dressing. The hazard analysis examined the main materials, industrial water, microbial evaluation, and airborne microorganisms of each working area, as well as the pathogenic microbial contamination risk. The survey was conducted at SJ Company in Jincheon (Chungchengbuk-do), Korea for 30 days from April 1, 2012 to April 30, 2012. The results showed that raw material microorganisms had a total plate count in industrial water below $3.00{\times}10$ CFU/mL in working room I, working room II, the packing room, washing water, and the inspection room for five times in each place. During dressing production (including heat treatment and mixing), general bacteria were detected at an average of $3{\times}10$ CFU/mL, but yeast, mold, and pathogenic bacteria were not detected. Airborne microbiological evaluation (for total plate count, yeast, and mold) found levels below the legal limit at each working area. While workers were positive for microbes in total plate counts, coliform and Staphylococcus aureus were not detected. In conclusion, standards for hygienic management should be established to prevent and decrease hazards, such as general bacteria and pathogenic microorganisms (for example, E. coli, B. cereus, Listeria spp, Salmonella spp, Staph. aureus, Clostridium perfringens, yeast, and mold), and to found critical limits for microorganisms with an HACCP system.

Recovery Process of Vanadium from the Leaching Solution of Salt-Roasted Vanadate Ore (바나듐광 염배소물 수침출 용액으로부터 바나듐 회수공정 고찰)

  • Yoon, Ho-Sung;Heo, Seo-Jin;Park, Yu-Jin;Kim, Chul-Joo;Chung, Kyeong Woo;Kim, Rina;Jeon, Ho-Seok
    • Resources Recycling
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    • v.31 no.2
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    • pp.40-48
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    • 2022
  • In this study, the effects of solution components were investigated in the recovery of vanadium as ammonium metavanadate from vanadium-ore-salt roasting-water leaching solution. The vanadium-containing solution is strongly alkaline (pH 13), so the pH must be lowered to 9 or less to increase the ammonium metavanadate precipitation efficiency. However, in the process of adjusting the solution pH using sulfuric acid, aluminum ions are co-precipitated, which must be removed first. In this study, aluminum was precipitated in the form of an aluminum-silicate compound using sodium silicate, and the conditions for minimizing vanadium loss in this process were investigated. After aluminum removal, the silicate was precipitated and removed by adjusting the solution pH to 9 or less using sulfuric acid. In this process, the concentration and addition rate of sulfuric acid have a significant influence on the loss of vanadium, and vanadium loss was minimized as much as possible by slowly adding dilute sulfuric acid. Ammonium metavanadate was precipitated using three equivalents of ammonium chloride at room temperature from the aluminum-free, aqueous solution of vanadium following the pH adjustment process. The recovery yield of vanadium in the form of ammonium metavanadate exceeded 81%. After washing the product, vanadium pentoxide with 98.6% purity was obtained following heat treatment at 550 ℃ for 2 hours.

Current Status of the Research on the Postharvest Technology of Melon(Cucumis melo L.) (멜론(Cucumis melo L.) 수확 후 관리기술 최근 연구 동향)

  • Oh, Su-Hwan;Bae, Ro-Na;Lee, Seung-Koo
    • Food Science and Preservation
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    • v.18 no.4
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    • pp.442-458
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    • 2011
  • Among Cucubitaceae, melon (Cucumis melo) is one of the most diversified fruits, with various forms, sizes, pulps, and peel colors, In addition, it is a commercially important crop because of its high sweetness, deep flavor, and abundant juice. In the species, there are both climacteric and non-climacteric melons depending on the respiration and ethylene production patterns after harvest. Ethylene is also considered a crucial hormone for determining sex expression, Phytohormones other than ethylene interact and regulate ripening, There are some indices that can be used to evaluate the optimum harvest maturity. The harvest time can be estimated after the pollination time, which is the most commonly used method of determining the harvest maturity of the fruit. Besides the physiological aspects, the biochemical alterations, including those of sweetness, firmness, flavor, color, and rind, contribute to the overall fruit quality. These changes can be categorized based on the ethylene-dependent and ethylene-independent phenomena due to the ethylene-suppressed transgenic melon. After harvest, the fruits are precooled to $10^{\circ}C$ to reduce the field heat, after which they are sized and packed. The fruits can be treated with hot water ($60^{\circ}C$ for 60 min) to prevent the softening of the enzyme activity and microorganisms, and with calcium to maintain their firmness. 1-methylenecyclopropene (1-MCP) treatment also maintains their storability by inhibiting respiration and ethylene production. The shelf life of melon is very short even under cold storage, like other cucurbits, and it is prone to obtaining chilling injury under $10^{\circ}C$. In South Korea, low-temperature ($10^{\circ}C$) storage is known to be the best storage condition for the fruit. For long-time transport, CA storage is a good method of maintaining the quality of the fruit by reducing the respiration and ethylene. For fresh-cut processing, washing with a sanitizing agent and packing with plastic-film processing are needed, and low-temperature storage is necessary. The consumer need and demand for fresh-cut melon are growing, but preserving the quality of fresh-cut melon is more challenging than preserving the quality of the whole fruit.