Curve - Fitting Program for Reaction Progress Curves

홍정화(Jeong-Hwa Hong),최진호(Jin-Ho Choi),변대석(Dae-Seok Byun) 한국식품영양과학회 1990 한국식품영양과학회지 Vol.19 No.3

포화성장모델을 이용하여 반응시간에 따른 생성물의 양을 예측하였다. 수용성 기질-수용성 효소간의 반응뿐만 아니라 비수용성 기질-수용성 효소간의 반응 결과에도 이 모델은 뛰어난 예측성을 나타내었다. 그외에도 측정치의 정확도도 이 모델로 대략 평가할 수 있었다.<br/> 사용자가 편리하도록 컴퓨터 프로그램을 BASIC 언어를 사용하여 제시하였고 이 프로그램을 이용하여 Pmax와 K 상수 값을 결정하고 상대오차의 평균값도 계산하였다. Saturation growth model was evaluated to predict the formation of product as a function of time. Good agreement was observed with homogenous and heterogenous reactions. Prediction of product yield can be made reasonably using this model. In addition, accuracy of measured values can be roughly evaluated by this model. User-friendly computer program in BASIC was written to evaluate the constants Pmax and K as well as averages of relative errors.

Acetylation of Fish Protein from Alaska Pollack

홍정화(Jeong-Hwa Hong),최진호(Jin-Ho Choi),변대석(Dae-Seok Byun) 한국식품영양과학회 1990 한국식품영양과학회지 Vol.19 No.3

명태(Alaska pollack)의 근원섬유 단백질을 Acetic anhydride로 pH 7.5 25℃에서 화학적으로 수식하였다. 그리고 이에 따른 기능성의 변화를 조사하였다. 근원섬유단백질의 아세틸화는 그 수식정도에 따라 독특한 기능성을 가진 단백질을 만들어냈다. 따라서 적합한 수식정도의 선택에 따라 단백질 용해도, 열 응고성 칼슘 침전성과 거품 및 유화성을 조절할 수 있음을 제시하였다. Myofibrillar protein from Alaska pollack was modified with acetic anhydride at pH 7.5 and 25℃ and changes in functional properties as affected by the degree of modification were determined. Acetylation of myofibrillar protein resulted in protein with unique functional properties dependent upon the degree of acetylation. By selecting appropriate degree of modification, it was possible to control protein solubility, heat coagulability, calcium precipitability, foaming and emulsion capacity.

고등어 아가미에서 추출한 Lipoxygenase 의 특성

홍정화,심선엽,변대석 ( Jeong Hwa Hong,Sun Yup Shim,Dae Seok Byun ) 한국수산과학회 1994 한국수산과학회지 Vol.27 No.6

Lipoxygenase of mackerel gill exhibited the highest reactivity toward eicosapentaenoic acid (EPA) followed by arachidonic acid, linoleic acid. The optimum pH were pH 4.5, 5.0 and 4.8 for EPA, arachidonic acid and linoleic acid, respectively. The enzyme was the most stable at pH 5.5. Optimum temperature was 25℃ for all substrate fatty acids. For linoleic and arachidonic acids the highest thermal stability was observed at 8℃; whereas, for (EPA) at 20℃. Optimum ionic strength was 0.22M. Sn^(2+), vitamin E and catechin completely inhibited the enzyme at the concentration of 1.0mM. Molecular weight of the enzyme was 42,000 dalton.

오징어 내장으로부터 추출한 지질성분의 항산화효과

정용실,홍정화,변대석 ( Yong Sil Jeong,Jeong Hwa Hong,Dae Seok Byun ) 한국수산과학회 1994 한국수산과학회지 Vol.27 No.6

To utilize waste of squid effectively, antioxidant properities of squid viscera were elucidated. Major fatty acids of total lipid, neutral lipid and phospholipid were C_(16:0), C_(18:1), and C_(20:5), C_(22:6) and consisted 63∼71% of total fatty acids. Total lipid did not show significant antioxidant activity when added to the fish oil at the concentration below 5.0%, Antioxidant activity of hexane extract was lower than total lipid or tetra carbon chloride-methanol(CCl₄-MeOH) extract. Extracts with CCl₄-MeOH exerted higher antioxidant activity as the methanol ratio was increased, suggesting that polar lipid plays and important role.

고등어 내장으로부터 추출한 지질성분의 항산화효과

정용실(Yong-Sil Jeong),홍정화(Jeong-Hwa Hong),변대석(Dae-Seok Byun) 한국식품영양과학회 1995 한국식품영양과학회지 Vol.24 No.1

미이용자원의 효율적인 이용을 위해서 고등어 내장으로부터 항산화물질을 추출하여 그 효과를 알아보고자 본 실험을 행하였다. 내장으로 부터 총지질을 추출하여 다시 헥산 추출물, 사염화탄소-메탄올 추출물(1 : 1, 1 : 3, 1 : 9, v/v), 안지질, 포스파티딜콜린(PC), PC를 제외한 나머지 인지질획분(PCF)로 추출하여 40℃ 항온기에서 10일간 산화억제실험을 하였다. 그 결과 핵산 추출물은 총지질이나 사염화탄소-메탄올 보다 산화억제 효과가 낮았고 사염화탄소-메탄올(1 : 1, 1 : 3, 1 : 9 v/v) 추출물은 극성이 높을수록 효과가 컸다. 극성지질인 인지질(PL)과인지질을 구성하는 포스파티딜콜린(PC)과 그 나머지 획분(PCF=PC free PL)도 모두 현저한 산화억제 효과를 나타내었으며 그 중에서도 PC가 가장 효과적인 것을 알 수 있었다. PC의 항산화 효과를 알아 보기 위해 천연 및 합성항산화제와의 효과를 비교한 결과 PC첨가군이 다른 항산화제 보다 2~3배 산화억제력이 높게 나타났다. 이상의 결과를 종합해보면 인지질의 항산화작용을 인정할 수 있으며 그 주체는 PC임을 알 수 있다. 수산폐기물로 부터 항산화물질의 이용이라는 대단히 긍정적인 결과와 함께 어유의 산화안정 효과에 대단히 큰 영향을 미치리라고 예상된다. To utilize the mackerel viscera effectively, antioxidant substances were extracted and the effects on the oxidation were evaluated. Total lipid(TL) extracted from mackerel viscera were fractionated into hexane extracts, tetracarbon chloride (CCl₄)-methanol (1 : 1, 1 : 3, 1 : 9, v/v) extracts, phospholipid (PL), phospha-tidylcholine (PC), and PC free fractions (PCF). Inhibition of fish oil oxidation was investigated using these fractions. Hexane fraction showed lower antioxidant activity compared to the TL or CCl₄-methanol fractions-(C-M) ; in addition, antioxidant activities increased as polarity of C-M increased. Significant antioxidant activities were observed with PL, PC, and PCF ; among them, PC was the most effective. To determine the antioxidant activity of PC, effects of natural or synthetic antioxidant were compared. Addition of PC to fish oil proved to enhance antioxidant activity the antioxidant activity of phospholipids was derived mainly from PC.

Effects of Phospholipid Extract from Squid Viscera on Lipid Oxidation of Fish Oil

정용실(Yong-Sil Jeong),홍정화(Jeong-Hwa Hong),김인수(In-Soo Kim),변대석(Dae-Seok Byun) 한국식품영양과학회 1995 한국식품영양과학회지 Vol.24 No.3

오징어 내장으로 부터 인지질(PL)을 추출하고 이것을 포스파티딜콜린 (PC)과 나머지 부분 (PCF)으로 나누어 각각의 항산화효과를 검토하였다. 추출획분의 고도불포화지방산 (PUFA)의 함량은 각각 PC(46.7%), PL(44.8%), PCF(40.9%)의 순으로 PC 획분이 불포화도가 가장 높은 것으로 나타났다. 이들 각 획분을 정제어유에 중량당 5% 농도(w/w)로 첨가하여 40℃에서 10일간 저장하면서 정제어유의 산화안정성에 미치는 영향을 조사하였다. 과산화물가는 저장 2일째 까지는 비슷한 경향을 보였으나 그 이후에는 PC획분 첨가군이 가장 높은 산화안정성을 보였으며, PL과 PCF 첨가군에서도 대조군에 비해서 어유의 산화안정성에 있어서 효과가 대단히 높은 것으로 나타났다. PC의 산화안정성 효과는 정제어유에 BHT(0.05%), 카테킨(1%), 토코페롤(1%)을 첨가하였을 때 보다 높은 항산화효과를 보였다. Phospholipid (PL), phosphatidylcholine (PC) and phosphatidylcholine free PL (PCF) were extracted from squid viscera and the antioxidant effects of each fraction on the oxidation of refined fish oil were evaluated. Polyunsaturated fatty acid contents were the highest in PC (46.7%) followed by PL (44.8%) and PCF (40.9%). The effects of each phospholipid fraction on stabilizing fish oil were compared by incubating at 40℃ for 10 days. At the initial period (2 days), changes in peroxide value did not show any significant difference ; however, as incubation time was extended, PC fraction showed the strongest antioxidant activity. PL and PCF added to fish oils also resulted in increased stability against oxidation. Antioxidative effect of PC at the 5% level was equivalent to 0.05% BHT, 1% catechin and 1% tocopherol.

Oxidation Stability Model of Fish Oil

김진우(Jin-Woo Kim),홍정화(Jeong-Hwa Hong),변대석(Dae-Seok Byun) 한국식품영양과학회 1995 한국식품영양과학회지 Vol.24 No.3

어유는 고도불포화지방산 함량이 높아 산화가 쉽게 되므로 식품가공용이나 기능성식품으로 응용되기에는 많은 제약이 따른다. 이러한 문제를 해결하기 위하여 어유의 산화안정성을 예측할 수 있는 기본 모델을 다음과 같은 식을 이용하여 제시하였다. dp/dt= kㆍp(t)ㆍ[Pmax-p(t)]. 상기식을 적분하면, p(t)=Pmax/[1+{(Pmax/P(o)-1)ㆍEXP(-K_pㆍ(t)]. 여기서 산화온도가 50, 60와 70 및 80℃일 때, K_p는 각각 0.00535, 0.01345와 0.02516 및 0.04675였다. 상기식은 대부분 측정치와 잘 일치하였다. 또한 K_p를 아래와 같이 온도의 함수로 표현할 수 있었다. K_p=(1/Pmax) EXP [1-(8148/T)+20.1]. 여기서 T 절대온도 (°K)이다. High content of polyunsaturated fatty acid in fish oil makes it very susceptible to oxidation, which prevent fish oil from successful application to food processing or functional foods. To resolve this problem, oxidation stability model of fish oil was developed using the following differential equation : dp/dt= kㆍp(t)ㆍ[Pmax-p(t)]. This differential equation can be integrated using analytical techniques to give : p(t)=Pmax/[1+{(Pmax/P(o)-1}ㆍEXP(-K_pㆍt)]. At 50, 60, 70 and 80℃, K_p were 0.00535, 0.01345, 0.02516 and 0.04675, respectively. The proposed model was well agreed with the measured data except for some minor deviations. In addition, K_p was expressed as a function of temperature : K_p= (l/Pmax) EXP [1-(8148/T)+20.1]. Where T is absolute temperature (°K)

n-3 고도 불포화 지방산의 산화억제에 미치는 플라보노이드와 α - 토코페롤의 효과 : 1 . 정제어유의 가열 및 저장 중 산화억제 효과 1 . Inhibition of Fish Oil Oxidation by Heating and During Storage

변대석,홍정화,정동윤,권미나 한국수산학회 1994 한국수산과학회지 Vol.27 No.2

To evaluate the antioxidant effect of flavonoids and α-tocopherol on purified fish oil(up to 40% of n-3 polyunsaturated fatty acids), lipid peroxidation, and fatty acids content dosing storage and upon heating were determined. The potential of these compounds for inhibiting and delaying both oxidation and lipoxygenase processes was also evaluated. The oxidation of fish oil was effectively inhibited by flavonoids and α-tocopherol. The antioxidizing effect of them compounds increased in proportion to their concentration. The addition of α-tocopherol and catechin-α-tocopherol mixture were prolonged induction period of lipid oxidation by 3.5 to 4 times. All other flavonoids also shown more than twice the prolonging effect. Lipoxygenase activity was decreased by catechin and α-tocopherol effectively.

n-3 고도 불포화 지방산의 산화억제에 미치는 플라보노이드와 α - 토코페롤의 효과 : 2 . 지질과산화를 촉진시킨 흰 쥐의 체내지질의 산화 억제 효과 2 . Antioxdizing Effect of Catechin and α - Tocopherol in Rats with Chemically Induced Lipid Peroxidation

변대석,홍정화,권미나,정동윤 한국수산학회 1994 한국수산과학회지 Vol.27 No.2

To evalulate the antioxidant effect of flavonoid(+)-catechin on n-3 polyunsaturated fatty acids in vivo, rats were fed with diets containing 5% corn oil(CO), 5% corn oil and 15% purified fresh fish oil(FO) or peroxidized fish oil(PFO) for 10 days. To accerelate lipid peroxidation, all of them were injected with 60㎎ phenobarbital(a day per ㎏ body weight), and treated with phorone(diisopropylidene acetone) before the rats were killed. Contents of triglyceride, phospholipid, cholesterol and lipid peroxide and the activities of GOT, GPT in serum and total lipid and cholesterol content in liver of PFO group rats were significantly higher than those of the FO one. Contrary to our expectations, the activities of superoxide dismutase(SOD), catalase and glutathione peroxidase(GSH-Px) in liver of the FO group were lower than those of the PFO group. These results might be explained as the results of homeostasis. Even though the hepatic glutathione were depleted, catechin and α-tocopherol inhibited production of lipid peroxide effectively. These results suggested that catechin be considered an antioxidative and hepatoprotective agent.