Influence of mixing ratio of blending oil (rice bran oil : RBD palm olein = 1 : 1, 1 : 4 mixture: w/w) and natural tocopherol, citric acid, and sodium polyphosphate on enhancement of oxidation stability of blending oil under the condition of tap water infulx(1 ml/min/200g oil) were compared by AOM test after heating these system at l80℃. In addition, the effects of tocopherol, and synergist on oxidition stability were also tested with potato chips fried with blending oil(1 : 4 mixture). The result obtained were as followes; 1. The test of RBD palm olein addition of 50% and 80% against rice bran oil on oxidation stability showed that the higher the palm olein contents in blending oil, the higher the oxidation stability. 2. The test of oxidation stability, adding l00ppm, 200ppm and 400ppm of natural tocopherol in two different types of blending oils, A(1 : 1 mixture) and B(1 : 4 mixture), disclosed that blending oil B was more positively effective, and this trend was superior at 200ppm level particularly, Furthermore, oxidation stability was enhanced remarkably upon addition of 100ppm of natural tocopherol, and 50ppm of citric acid together with 50ppm, 100ppm and 200ppm of sodium polyphosphate in general. Especially, 200ppm of sodium polyphosphate addition induced the most synergetic effect on oxidation stability showing as much as 3 times compare to control. 3. The results of oxidation stability obtained by peroxide value on potato chips fried with blending oil (1:4 mixture added tocopherol, citric acid and sodium polyphosphate and preserved at 60℃ revealed that addition of tocopherol and 50ppm of citric acid together with 200ppm of sodium polyphosphate treatment was the most synergistic coinciding with AOM test results.

The oxidative stability of palm oil with moisture addition during heationg was investigated and the antioxidant effects of tocopherol, citric acid and sodium polyphosphate were evaluated. The addition of natural tocopherol up to 200 ppm level did not improve the oxidative stability of palm oil with moisture (1m1 H2O additive to 200g of oil at 180℃). The maximum antioxidant effect was observed at the Concentration of 400 ppm. Addition of citirc acid did not influence the effective concentration of tocopherol. Whereas addition of sodium polyphosphate and citric acid increased the antioxidant effect of tocopherol. The maximum synergistice effect was observed at the concentrations of 50 ppm citric acid and 50 ppm of sodium polyphosphate. Addition of 50 ppm citric acid and 50 ppm sodium polyphosphate to 100 ppm of tocopherol exceeded the antioxidant effect of 400 ppm tocopherol alone.

Background : Kalopanax pictus is one of the most popular wild vegetables in Korea. In recent years Kalopanax pictus has been developed which has no thorns that can be efficiently harvested. Kalopanax pictus, now without thorns, breeds only by root cutting. This makes the price of ineffective and invisible Kalopanax pictus high. Therefore, tissue culture is necessary for efficient mass proliferation of visibly absent Kalopanax pictus. This study was conducted to investigate the effect of anti-browning treatment on tissue culture of thornless Kalopanax pictus. Methods and Results : Thornless Kalopanax pictus young leaves were cut into 5 ㎜ in diameter and cultured for 1 month at 2,4-D 1 ppm + TDZ 0.1 ppm + 3% sucrose. Add 0.05%, 0.1%, 0.15% and 0.2 ㎎/ℓ of browning inhibitor such as ascorbic acid, citric acid and activated charcoal to the MS + 2,4-D 0.2 ppm + 5% sucrose medium. And cultured at 25℃ for 24 hours Light condition for 1 month. In order to determine the optimum concentration of browning agent, characteristics such as callus size, adventitious shoot formation rate and browning degree were investigated. As a result, the callus size of ascorbic acid 0.05 ㎎/ℓ was the largest at 2.26 ± 0.4 ㎝ and the adventitious shoot formation rate was the highest at 16.4%. The degree of browning was 40.30 ± 4.92 in L value and 5.00 ± 2.23 in b value. Conclusion : When ascorbic acid 0.05 ㎎/ℓ is added to the secondary culture medium, the size of the callus increases and the degree of browning decreases. Using the above-mentioned results, we can establish a mass proliferation system through tissue culture of Thornless Kalopanax pictus.

A continuous process of persulfate oxidation and citric acid washing was investigated for ex-situ remediation of complex contaminated soil containing total recoverable petroleum hydrocarbons (TRPHs) and heavy metals (Cu, Pb, and Zn). The batch experiment results showed that TRPHs could be degraded by Fe2+ activated persulfate oxidation and that heavy metals could be removed by washing with citric acid. For efficient remediation of the complex contaminated soil, two-stage and three-stage processes were evaluated. Removal efficiency of the two-stage process (persulfate oxidation - citric acid washing) was 83% for TRPHs and 49%, 53%, 24% for Cu, Zn, and Pb, respectively. To improve the removal efficiency, a three-stage process was also tested; case A) water washing - persulfate oxidation - citirc acid washing and case B) persulfate oxidation - citric acid washing (1) - citric acid washing (2). In case A, 63% of TRPHs, 73% of Cu, 60% of Zn, and 55% of Pb were removed, while the removal efficiencies of TRPHs, Cu, Pb, and Zn were 24%, 68%, 62%, and 59% in case B, respectively. The results indicated that case A was better than case B. The three-stage process was more effective than the two-stage process for the remediation of complex-contaminated soil in therms of overall removal efficiency.

Magnetite (Fe3O4) has been prepared directly to avoid the reduction process prior to the H2 production from the high temperature water gas shift reaction of the simulated waste derived synthesis gas. Citric acid has been employed as a complexing agent for the direct synthesis of magnetite. Notably, without the reduction process, the catalyst prepared at the citric acid molar ratio of 1.0 showed 80% CO conversion at 350℃ at a gas hourly space velocity of 40,057 h-1.

새싹 채소 중 무순의 위생적인 재배 조건을 설정하기 위하여 종자세척 및 관수로서 이산화염소수, citric acid 및 glycerin의 적용 효과를 조사하였다. 무 종자에 인위적으로 오염시키기 위하여 Salmonella typhimurium은 실험실 조건에서 배양하였으며, 무 종자를 S. typhimurium 현탁액에 침지시켜 균수를 약 로 조절하였다. 무 종자에 대한 세척 효과는 이산화염소수 및 citric acid의 단독처리보다 병행처리시

강활의 캘러스 및 식물체 중 Ge 함량에 미치는 GeO2와 구연산의 영향을 구명하기 위하여 식물체 부위별로 캘러스를 유도하고 캘러스 증식시 GeO2와 구연산을 농도별로 처리하여 증식율 및 캘러스의 Ge 함량을 조사하였으며 강활을 pot에 재배하여 GeO2와 구연산을 농도별로 시용하여 식물체 중의 Ge 함량을 조사한 결과를 요약하면 다음과 같다. 1. 캘러스 유도는 소엽병 〉 엽병 〉 소엽 순으로 잘 되었고, 생장 조절제는 2, 4 - D 1. 0ppm에서 가장 잘되었다. 2. 캘러스 증식에는 2, 4 - D 농도별로는 2, 4 - D 2. 0ppm에서, 2, 4 - D 2. 0ppm이 첨가된 배지에서 GeO2 농도별로는 GeO2 2. 5ppm에서 2, 4 - D 2. 0ppm과 GeO2 2. 5ppm 첨가한 배지에서 구연산 농도와 pH별로는 구연산 0. 1, 1mM, pH 6에서 캘러스 증식이 가장 좋았다. 3. 캘러스 중 Ge 함량은 GeO2 시용량이 20ppm까지는 많을수록 높았고, 구연산과 pH 별로는 구연산은 0. 1mM, pH는 낮을수록 Ge 함량이 높았다. 4. 식물체 부위별 Ge 함량은 잎 〉 뿌리 〉 줄기 순으로 함량이 높았으며, GeO2 시용으로 Ge 함량이 높았고, 구연산 시용은 구연산 1mM에서 Ge 함량(含量)이 가장 높았고, 10mM 이상에서는 오히려 감소되었다. 5. GeO2 시용량 증가는 캘러스나 식물체 중 GeO2 함량을 증가시키나 기타 무기성분 함량은 감소되는 경향이었고 구연산 0. 1~1mM 시용으로 약간 증가되는 경향이다.