• 한국식품영양학회지
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• 제27권1호
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• pp.75-79
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• 2014

The following study is the result of herbal teas puffed at different temperatures between $140{\sim}220^{\circ}C$. Depending on treatment temperatures, the water contents decreased, while some carbonization occurred and crude ash contents relatively increased. Also, the crude protein and crude fat experienced little changes. B(${\alpha}$)P contents (0.16~0.17 ppb) showed little change according to treatment temperatures. From this result, the B(${\alpha}$)P content differed depending on the treatment temperature and raw materials. Solid elution rate figures of the herbal teas ranged from 0.27~0.45% (w/w) and the rate of solid elution increased along with higher puffing temperatures. The reason for the increase in solid elution rates is due to the breakage of cross bridges between the raw materials in the herbal tea which are carbohydrates, proteins, lipids and etc. after treatments of physical changes rather than chemical ones.

• 한국응용과학기술학회지
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• 제31권4호
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• pp.703-710
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• 2014

한방차의 roasting 온도를 $80{\sim}140^{\circ}C$ 범위로 하여 성분 변화를 분석한 결과, 온도의 상승에 따라 수분함량이 감소하고 일부 탄화가 발생하며 조 회분 함량이 소폭 상승하였고, 조 지방 및 조단백질 함량은 소폭 감소하였다. 한방차의 고형분 용출율은 0.15~0.32%(w/w)를 나타내었는데, roasting 온도가 상승할수록 감소하는 경향을 나타내었다. 처리온도가 $80{\sim}110^{\circ}C$구간에서는 큰 변화를 나타내지 않은 반면 $110{\sim}140^{\circ}C$구간에서는 고형분 용출율이 급격히 감소하였다. 온도가 상승할수록 용출율이 감소하는 것은 내부 조직이 치밀하여 상대적으로 용출이 어렵기 때문이다. 벤조피렌 함량은 0.29~0.51ppb으로 온도가 높을수록 $B({\alpha})P$함량이 증가하였다. 처리온도와 원재료에 따라 $B({\alpha})P$ 함량에 차이가 발생하며, 내부온도는 약 $200^{\circ}C$정도지만 roaster 표면의 실제 온도는 약 $2000^{\circ}C$에 이르는데 표면과 접촉한 부분에서 $B({\alpha})P$가 생성된다. $B({\alpha})P$는 주로 음식을 조리, 가공할 때 식품의 주성분인 탄수화물, 단백질, 지방 등이 열분해 되어 생성되는 것으로 생각된다.

• 한국응용과학기술학회지
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• 제31권2호
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• pp.305-312
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• 2014

팽화 처리온도를 각각 $140{\sim}220^{\circ}C$로 한 한방차 제품의 성분변화를 분석한 결과는 다음과 같다. 처리온도의 상승에 따라 일부 탄화가 발생하며 조회분 함량이 상대적으로 상승하는 소폭의 변화가 있었고, 조단백질 및 조지방 함량은 거의 변화가 없는 것으로 나타났으며 수분함량은 감소하였다. 한방차의 고형분 용출률은 0.18~0.27%(w/w)로 나타내었는데, 팽화온도가 상승할수록 증가하였다. 고형분의 용출은 온도가 화학적 변화보다 물리적 변화에 의해 식품의 원재료 성분인 탄수화물, 단백질, 지방 등이 천연 상태에서 상호가교 결합이 물리적인 힘으로 어느 정도 파괴되어 성분의 용출이 용이해지기 때문인 것으로 생각된다. 벤조피렌 함량은 0.18~0.24ppb로 처리온도, 원재료에 따라 B(${\alpha}$)P 함량에 차이가 발생한 것으로 나타났다.

• 한국응용과학기술학회지
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• 제30권4호
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• pp.790-796
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• 2013

Roasting 온도를 $80{\sim}140^{\circ}C$로 달리한 한방차의 성분 변화를 분석한 결과는 다음과 같다. 처리온도의 상승에 따라 수분함량이 감소하고, 일부 탄화가 발생하며 조회분 함량이 상대적으로 상승하는 소폭 변화가 있었고, 조단백질 및 조지방 함량은 거의 변화가 없는 것으로 나타났다. 벤조피렌 함량은 0.17~0.35ppb으로 처리온도가 상승할수록 $B({\alpha})P$ 함량이 증가하는 경향을 보였다. 이러한 결과를 볼 때, 처리온도와 원재료에 따라 $B({\alpha})P$ 함량에 차이가 발생한 것으로 나타났는데, roasting의 경우 실제 내부온도는 약 $200^{\circ}C$내외에 그치지만 roaster 표면의 온도는 약 $2,000^{\circ}C$에 이르기 때문에 이 표면과 직접 접촉한 부분에서 일부의 $B({\alpha})P$가 생성된 것으로 판단된다. 한방차의 고형분용출율을 0.18~0.35%(w/w)를 나타내었는데, roasting 온도가 상승할수록 고형분용출율이 감소하는 경향을 나타내었다. 처리온도가 $80{\sim}110^{\circ}C$처리구간에서는 큰 변화를 나타내지 않은 반면 $110{\sim}140^{\circ}C$처리구간에서는 고형분용출율이 급격히 감소하는 경향을 보였다. 처리온도가 상승할수록 고형분용출율이 감소하는 것은 내부 조직이 치밀하여 상대적으로 용출이 어렵기 때문으로 생각된다.

• 한국식품영양학회지
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• 제28권3호
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• pp.465-469
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• 2015

An analysis of changes in herbal tea composition according to the difference in processing conditions showed slightly reduced crude protein content and increased, moisture, crude fat and solid elution rate after treatment using the ash puffing process compared to roasting. Benzopyrene content was significantly reduced to 0.18 ppb from 0.51 ppb. This result indicated that, the $B({\alpha})P$ content differed depending on the processing condition and raw materials. Generation of food $B({\alpha})P$ is mainly include the thermal decomposition of food cooking, when the processing which is a main component of food carbohydrate, protein, fat reason despite severe heat treatment as a whole is to be detected even though the $B({\alpha})P$ in this way is considered to be. The taste, aroma and color did not show a large difference, but the strong bitters taste decreased.

• 한국물환경학회지
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• 제22권5호
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• pp.879-886
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• 2006

The analytical methods of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) for water sample with extremely low concentration was developed to extract large volume and to improve fast chromatography for clean up. Semi-automated solid phase extraction (SPE) system and column coupling chromatography using elution pump was optimized and applied to each processes of treatment plant. Results of disk type SPE indicated that this system was applicable below 40 L of aqueous sample with a flow rate of 0.08 ~ 0.2 L/min. Average recoveries of SPE using labeled sampling spike of $^{37}Cl$-2,3,7,8-TCDD was 97%. Column coupling method resulted in reduced clean up time, solvent volume, increased average recoveries with constant elution rate. The combined methods were applied to the monitoring of drinking water treatment plant. Limits of detection (LOD) of each process were calculated. For example, LOD of raw and treated water ranged 0.094~0.968 pg/L and 0.028~0.364 pg/L, respectively. Combined methods of extraction and cleanup techniques provided fast analysis of PCDD/Fs with high accuracy and low LODs for water samples.

• Bulletin of the Korean Chemical Society
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• 제28권2호
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• pp.276-280
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• 2007

In this work, caffeine and some catechin compounds + C, EC, EGC, and EGCG were extracted from green tea by using molecular imprinted polymers (MIP) as sorbent materials in a solid-phase extraction (SPE) process known as MISPE (molecular imprinted solid-phase extraction). For synthesis of MIP, caffeine was employed as the template, MAA as the monomer, EGDMA as the crosslinker, and AIBN as the initiator. A solution of caffeine (0.2 mg/mL in methanol) was utilized in the solid extraction cartridges following loading, washing, and elution procedures with acetonitrile, methanol, and methanol-acetic acid (90/10, %v/v) as the solvents, respectively. This solid-phase extraction protocol was applied for the extraction of caffeine and some catechin compounds from green tea. A comparison was made between the results obtained with the MIP cartridges and a traditional C18 reversed-phase cartridge. It was thereupon found that the recovery of caffeine by the MIPbased sorbent used in this work was almost two and four times greater than that by a commercially available C18 material. A quantitative analysis was conducted by high performance liquid chromatography (HPLC) using a C18 column (5 μm, 250 × 4.6 mm) with methanol/water (40/60, %v/v) as the mobile phase at a flow rate of 0.5 mL/min.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.337-341
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• 2001

A new method to extract gold from pyrite roster cinder, which combines ultra-fine-grinding with resin-in-pulp, has been studied in this paper. Compared with traditional leaching technology, it can short leaching time, avoid complex filter process, lower sodium cyanide consumption and increase gold recovery by 35%. During leaching, aluminium oxide ball was used as stirred medium, hydrogen peroxide as leaching aid and sodium hexametaphosphate as grinding aid. With the high efficiency and chemistry effect of ultra-fine-grinding, the leaching process was developed and the gold leaching rate may reach 88%. With AM-2 Б resin as abosorber and sulfocarbamide (TU) as eluent, gold was recovered from cyanide pulp by resin-in-pulp. AM-2 Б resin has good adsorbability in cyanide solution(pH=10). It was easy to elude gold from the loaded resin with 0.1㏖/L cholhydric acid and 1㏖/L sulfocabamide. The effect of contact time, temperature and acidity etc. on the gold absorption had been examined with static methods. The results showed that the adsorption and desorption of gold could both reach over 98%. The effects of flow rate of solution on dynamic adsorption and elution of gold had been examined with dynamic methods. Breakthrough curve and elution curve had been drawn in this paper. A mild condition was determined through a number of experiments: leaching time 2 hours, liquid solid ratio 4:1, sodium cyanide 3kg/t, hydrogen peroxide 0.05%, sodium hexametaphosphate 0.05%; adsorption time 30 minutes, temperature 10-3$0^{\circ}C$, resin($m\ell$) solid(g) ratio 1:10, eluent resin ratio 10-20:1, velocity of eluent $1.5m\ell$/min. Under the mild condition, the gold recovery may reach 85%.

• Journal of Radiation Protection and Research
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• 제45권4호
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• pp.154-162
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• 2020

Background: Several studies have reported that wild mushrooms contain high amounts of radioactive cesium (137Cs). After the Fukushima Daiichi Nuclear Power Plant Accident, a significantly high concentration of 137Cs has been detected in wild mushrooms, and their consumption may be the cause of the chronic internal exposure of local consumers to radioactivity. Therefore, an accurate evaluation of the internal radioactivity resulting from mushroom ingestion is needed. Materials and Methods: The 137Cs elution rate through the cooking and digestion stages was evaluated using in vitro experiments. The edible mushroom Pleurotus djamor was taken as a sample for the experiments. The mushrooms were cultivated onto solid media containing 137Cs. We evaluated the internal dose based on the actual conditions using the elution rate data. For various cooking methods, the results were compared with those of other wild edible mushrooms. Results and Discussion: From the elution experiment through cooking, we proved that 25%-55% of the 137Cs in the mushrooms was released during soaking, boiling, or frying. The results of a simulated digestion experiment after cooking revealed that almost all the 137Cs in the ingested mushrooms eluted in the digestive juice, regardless of the cooking method. The committed effective dose was reduced by 20%-75% when considering the dissolution through the cooking process. Conclusion: We found that cooking lowers 137Cs concentration in mushrooms, therefore reducing the amount of radioactivity intake. Besides, since there were differences between mushroom types, we demonstrated that the internal exposure dose should be evaluated in detail considering the release of 137Cs during the cooking stages.

• 한국환경과학회지
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• 제19권9호
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• pp.1119-1127
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• 2010

The behavior of copper throughout the whole process of wastewater treatment plant that uses the activated sludge process to treat the wastewater of petrochemical industry that contains low concentration of copper was investigated. Total inflow rate of wastewater that flows into the aeration tank was $697\;m^3$/day with 0.369 mg/L of copper concentration, that is, total copper influx was 257.2 g/day. The ranges of copper concentrations of the influent to the aeration tank and effluent from the one were 0.315 ~ 0.398 mg/L and 0.159 ~ 0.192 mg/L, respectively. The average removal rate of copper in the aeration tank was 50.8 %. The bioconcentration factor (BCF) of copper by microbes in the aeration tank was 3,320. The accumulated removal rate of copper throughout the activated sludge process was 71.3%, showing a high removal ratio by physical and chemical reactions in addition to biosorption by microbes. The concentration of copper in the solid dehydrated by filter press ranged from 74.8 mg/kg to 77.2 mg/kg and the concentration of copper by elution test of waste was 2.690 ~ 2.920 mg/L. It was judged that the copper concentration in dehydrated solid by bioconcentration could be managed with the control of that in the influent.