감자를 마이크로웨이브 콜드 플라스마(microwave-powered cold plasma, MW-CP)로 처리한 후, 처리된 감자 내 polyphenol oxidase (PPO) 저해에 있어 표면적 대 부피 비의 영향을 관찰하였고, 형광 측정을 통해 단백질 구조의 변화를 관찰하였으며, 처리의 pH 및 저장 중 색도와 갈변도의 변화를 연구하였다. 또한, 감자에서 추출한 PPO 시료를 MW-CP 처리하여 Weibull model을 이용한 처리 시간에 따른 효소 활성을 예측하였다. MW-CP 형성 가스로 공기(O221%/N2)를 사용하였고, 667 Pa 압력에서 처리 전력 900 W로 40분 동안 감자를 MW-CP 처리하였다. 감자에서 추출한 PPO 시료는 처리 전력(500, 600, 800, 그리고 900 W)과 처리 시간(0, 10, 20, 30, 그리고 40분)을 다르게 하여 MW-CP 처리하였다. 감자의 표면적 대 부피 비가 7.13과 9.00일 때, PPO의 잔존 활성도는 각각 72.4와 58.9%로 표면적대 부피 비가 클수록 높은 저해 정도를 보였다(p<0.05). MW-CP 처리한 감자는 무처리군보다 유의적으로 낮은 형광강도를 보여(p<0.05), 단백질 구조의 변화로 인해 PPO의 활성이 저해되었음을 알 수 있었다. MW-CP 처리 전후 시료의 pH는 각각 6.5 ± 0.1과 6.5 ± 0.0으로 유의적인 차이를 보이지 않았으며(p>0.05), 감자의 명도는 처리 전보다 후가 더 높았고(p<0.05), 저장 시간이 지날수록 낮아졌다(p<0.05). 적색도와 황색도는 MW-CP 처리 전후의 변화가 없었으며, 황색도는 저장 시간이 지나도 유의적인 차이를 나타내지 않았다(p>0.05). MW-CP 처리된 감자의 갈변도는 처리되지 않은 감자보다 더 낮은 값을 보여(p<0.05), 색 관찰을 통해 MW-CP 처리가 감자의 갈변을 지연시킴을 알 수 있었다. Weibull model의 R2값은 처리 전력이 500, 600, 그리고 800 W일 때 각각 0.84, 0.76, 그리고 0.80으로 PPO 저해 예측에 적합함을 알 수 있었다. 본 연구를 통해 MW-CP 처리가 감자의 PPO를 저해시킬 수 있는 기술로서의 가능성을 확인하였다.

This study was conducted in an effort to investigate the effect of Maillard reaction products (MRPs) on enzymatic browning of burdock and their anti-oxidant activity. The MRPs were prepared by heating glucose and amino acids at 90°C, which served to produce a strong inhibitory effect on burdock polyphenol oxidase. As the reaction time of the solution containing glucose and amino acid increased at 90°C, the production of MRPs increased and intensity of the brown color deepened. When MRPs were prepared by heating at 90°C for five hours, the absorbance of MRPs from glucose and lysine was 6.44, while those of glucose and glycine was 1.95. The MRPs synthesized from the glucose and lysine also reduced the pH of MRPs from 5.60 to 4.51, but those from glucose and glycine decreased slightly from 5.57 to 5.33. The Michealis-Menten constant value (Km) of burdock PPO with pyrocatechol as a substrate was 16.0 mM, and MRPs were a non-competitive inhibitor against burdock PPO. The anti-oxidant activity of MRPs was measured by evaluating its radical scavenging activities of DPPH radicals, ABTS radicals and reducing power. The color intensity of MRPs produced by lysine and glucose were deeper than that produced by glucose and glycine. It was also found that MRPs produced from glucose and lysine exhibited stronger anti-oxidant properties than those produced by glucose and glycine.

Hunter's color value “a” in dried-persimmon of table and full ripe fruit was higher than that in unripe fruit. In case of soluble solid content, full ripe fruit was 50o Brix, the highest degree, while unripe fruit was 40o Brix, the lowest degree. PPO activation of unripe fruit was 4.7, which was higher than table-ripe fruit (0.7) and full ripe (1.0). Polyphenol oxidase activation remained even while drying, but there was no difference in PPO activation degree as drying period increased. Total phenol content of unripe fruit was 101.4, which was higher than table-ripe fruit (57.5) and full ripe fruit (67.4). Total phenol content level increased as drying period increased, which was based on fresh weight. Hardness of unripe and table ripe fruit continued to decrease until three weeks during softening. After that, hardness was high and it started drying. However, in full ripe fruit, hardness increased after two weeks and softening was fast during the drying period, and its weight reduction rate was lower than that of unripe and table ripe fruit.

The antioxidant, xanthine oxidase, tyrosinase inhibitory activities and polyphenol contents of the fruiting bodies of Pleurotus cornucopae extracted with acetone, hot water and methanol (hereinafter referred to Fr. Ace, Fr. HW and Fr. MeOH). The antioxidant activities in the Fr. Ace, Fr. HW and Fr. MeOH were 93.23%, 89.55% and 92.58%, respectively at the concentration of 2.0 mg/ml. Xanthine oxidase inhibition activity in the Fr. Ace, Fr. HW and Fr. MeOH were 45.84%, 46.50% and 45.60%, respectively at the concentration of 5 mg/ml. Tyrosinase inhibition activity in the Fr. Ace, Fr. HW and Fr. MeOH were 52.11%, 50.12% and 55.81%, respectively at the concentration of 1.0 mg/ml. Total polyphenol contents in the Fr. Ace, Fr. HW and Fr. MeOH were 18.99 mgGAEs/ g, 16.73 mgGAEs/g and 18.66 mgGAEs/g. These experimental results suggested that fruiting bodies of P. cornucopae contained good physio-chemical substances for promoting human health.

Three potato cultivars, Sumi,Daejima and Namjak, were prepared as slices. They were dipped in distilled water for 20 seconds. The potato slices were packed in polyethylene bags and stored at 5℃. Browning degree, total phenol and chlorogenic acid contents and polyphenol oxidase (PPO) activity were measured. And the correlation analysis of browning parameters were conducted. The results were as follows. There were increase in browning degree, phenolic content and PPO activity during cold storage of potato slices with different cultivars. Among three cultivars, Sumi showed the highest browning degree, phenolic content and PPO activity and also showed the highest % increse of browning and PPO activity during cold storage. On the contrary, Daejima was the lowest. But Daejima showed the highest % increase in phenolic contents during cold storage. With Sumi, browning degree was significantly correlated with PPO activity and phenolic contents (p〈0.05). With Daejima and Namjak, a significant correlation was found between browning degree and PPO activity (p〈0.05). From the above results, enzymatic browning reactions of potato slices and factors affecting them were dependent on cultivar. Among the tested three cultivars, Daejima showed the lowest browning degree during cold storage and thus seems to be desirable for minimal processing.

밤과실의 가공 및 저장중 갈변기구를 규명하는 일환으로 밤에 함유된 polyphenol 화합물 및 PPO를 분리, 동정하고 PPO의 생화학적 특성에 대해 연구한 결과는 다음과 같다. 밤의 total phenol 함량은 이었고 ferulic acid, caffeic acid, synapic acid, p-coumaric acid, gallic acid, salicylic acid 순으로 함량이 높았다. PPO를 분리, 정제하여 전기영동한 결과 단일의 단백질 및 효소활성밴드를 확인하였으며 정제된 효소의 비활성도는 260.9이고 조효소액보다 11.7배 정제되었다. PPO의 최적 pH와 온도는 각각 5.9, 였으며 효소활성은 에서 15분 처리시 거의 실활되었다. 무기염의 영향을 본 결과 , , 들은 효소활성을 증가시켰으나 , , 는 활성을 저해시켰다. 저해제로는 L-ascorbic acid, thiourea, sodium chloride, L-cysteine의 저해작용이 강했다. 밤의 PPO는 o-diphenol에 대한 강한 활성을 나타냈으며 특히 catech이에 대해 가장 강했으며 monophenol에는 활성을 나타내지 않았다. PPO의 Km값은 catechol에 대해 5mM이었다.

배과실(果實)의 PPO를 분리(分離) 정제(精製)한 후(後) 그 특성(特性)을 조사(調査)한 결과(結果)는 다음과 같다. 조효소액(粗酵素液)을 전기영동한 결과 2개의 활성분리대(活性分離帶)가 관찰(觀察)되었으며, 이 조효소액(粗酵素液)을 acetone 심몰(沈沒)과 DEAE-cellulose chromatography로 부분정제(部分精製)한 결과 PPO A 분획(分劃)과 PPO B 분획(分劃)을 얻었다. 각 구분을 전기영동(電氣泳動)한 결과 PPO A, B 각각 Rm치가 0.58, 0.68인 단일 활성분리대(活性分離帶)가 관찰(觀察)되었다. PPO A와 PPO B의 최종 정제도(精製度)는 각각 7.8와 8.7배(倍)였다. PPO A의 최적(最適) pH와 온도(溫度)는 pH 7, 인 반면 PPO B의 최적(最適) pH와 온도(溫度)는 pH 4.2, 로 나타났다. PPO A, B의 열(熱) 안정성(安定性)은 이상(以上)의 온도(溫度)에서는 급격히 활성(活性)이 감소했으며 PPO B보다 PPO A가 더 안전(安定)하였다. 배의 두 PPO는 o-diphenol에 강한 활성을 나타냈으며 특히 PPO A는 catechol에 PPO B는 chlorogenic acid에 활성이 강했다. 또한 PPO A는 pyrogallol에도 활성을 나타냈다. 그러나 두 PPO는 m-diphenol, p-diphenol과 monophenol에는 활성(活性)을 나타내지 않았다. 무기염(無機鹽)의 영향(影響)을 본 결과(結果)는 10mM농도(濃度)에서 은 PPO A의 활성(活性)을 증가(增加)시켰으나 는 저해(沮害)했고 반면 , 는 PPO B는 활성(活性)을 증가(增加)시켰으나 , , , 는 저해(沮害)했다. 는 저농도(低濃度)에서는 효소(酵素)를 활성화(活性化)시켰으나 10mM의 고농도(高濃度)에서는 저해작용(沮害作用)을 했다. 저해제(沮害劑)의 작용(作用)을 조사(調査)한 결과(結果), L-ascorbic acid, L-cysteine, thiourea 등이 저해작용(沮害作用)이 강했다. PPO A와 PPO B의 catechol에 대한 Km치는 각각 20mM과 14.3mM이었다.

사과 Fuji와 국광을 저온(低溫) 상태하(狀態下)에서 저장방법(貯藏方法)을 달리하였을 때, 내부갈변(內部褐變) 및 PPO.의 변화(變化)에 대하여 조사한 결과는 다음과 같다. 1. P.E film저장(貯藏)에 있어서 내부갈변(內部褐變) 정도(程度)는 11월(月)에 수확(收穫)한 Fuji가 10월(月)에 수확(收穫)한 Fuji보다 많았고, 0.09mm 2%구(區)에서 가장 많이 나타났고 0.06mm 2%구(區), 0.06mm 2%구(區)의 순(順)이었으며 를 완전히 제거(除去)한 감압저장(減壓貯藏)에서는 내부갈변(內部褐變)을 볼 수 없었다. 2. P.E film저장중(貯藏中) Fuji의 PPO. activity 및 PPO. specific activity는 11월(月) 수확(收穫)이 10월(月) 수확(收穫)에 비해 높았으며, 0.09mm의 2%구(區)가 0.06mm구(區)보다 높았고, 저장중(貯藏中) 증가(增加)하는 경향이었고, 를 완전히 제거(除去)한 감압저장(減壓貯藏) 동안 Fuji의 PPO. activity는 변화(變化)가 거의 없었으나 PPO. specific activity는 계속 감소(減少)하였다. 3. 국광의 PPO. activity는 Fuji에 비해 상당히 높았고 저장중(貯藏中) PPO. activity 및 specific activity는 저장(貯藏) 초기(初期)와 거의 차이(差異)가 없었다. 4. 이상(以上)으로 미루어 Fuji의 내부갈변(內附褐變)은 저온장해(低溫障害)보다는 장해(障害)로 보이며 품종간(品種間)의 PPO. activity의 정도(程度)와 내부갈변(內附褐變)의 관련(關聯)은 찾을 수 없는 것 같다. 그러나 Fuji의 경우 PPO. activity증대(增大)는 의 영향(影響)을 받은 것으로 보이며 내부갈변(內部褐變)과 어느정도 관련(關聯)이 있는 것 같다.

Background : We have previously reported that Oligonol, a low-molecular polyphenol derived from lychee fruit, has protective effect on the liver and kidney of diabetic animal model. In this study, we examined whether Oligonol has any beneficial effects on pancreas of diabetic rats. Methods and Results : Oligonol was orally administered at a dose of 10 and 20 mg/kg body weight for 10 days to STZ-induced diabetic rats, and the effects were compared with those of vehicle-treated diabetic control and non-diabetic control rats. The administration of Oligonol reduced hyperglycemia in diabetic rats through an improvement of serum and pancreatic insulin levels. The increased reactive oxygen species levels in pancreas of diabetic control rats was attenuated by the Oligonol administration through inhibiting the expression of NADPH oxidase-related proteins. The enhanced expression of pro-apoptotic proteins in pancreas of diabetic control rats was significantly reduced by Oligonol administration through down-regulation of phosphor-c-Jun N-terminal kinases protein in pancreas. Furthermore, the expressions of cell proliferation-related protein were also augmented in Oligonol treated-diabetic rats. However, Oligonol treatment led to improved histological changes in the pancreas. Conclusion : These pancreatoprotective effects of Oligonol were achieved through attenuation of oxidative stress and its sensitive protein expression associated with apoptosis and cell proliferation in diabetic rats.

밀가루와 면대 색이 밝은 품종의 육종효율을 증진하기 위하여 PPO 활성과 연관된 sequence-tagged site(STS) 분자표지인 PPO-05, PPO-16, PPO-18, PPO-30과 PPO-43을 이용하여 국내의 밀 품종의 PPO활성 수준과 유전자형 간의 관계를 분석하였다. Ppo-A1에 연관된 PPO-18이 국내 밀 품종의 PPO 활성 판별과 선발에 유용한 분자표지로 확인되었다. PPO 활성은 Ppo-A1b 유전자형 품종(0.446)이 P

밀가루 및 국수 면대의 색깔 변화에 영향을 미치는 요인을 분석하여 소비자가 선호하는 밝은 색택의 밀가루 및 국수 제조에 적합한 품종의 육성에 유용한 간편 분석법을 확립하고자 본 연구를 수행하였다. 국산밀 25 품종을 이용하여 종실 및 밀가루 특성과 저장기간 동안 국수 면대의 밝기 변화를 조사하였다. 종실의 PPO 활성은 천립중이 낮을수록, 종실 회분과 단백질 함량이 낮을수록 낮은 경향을 나타내었다. 종실의 PPO 활성은 총폴리페놀 함량(r=0.609**

Polyphenol oxidase (PPO) is implicated in discoloration of white salted noodles and other wheat based foods. PPO activity was evaluated to determine the effect on discoloration of noodle dough sheets prepared from 25 Korean wheat flours during storage and to screen experimental lines with low PPO activity in 52 Korean wheats. PPO activity was assayed with whole-seed and performed with L-dihydroxyphenylalanine (L-DOPA) as substrates. Absorbance by L-DOPA assay of 25 Korean wheats was from 0.285 to 1.368 at 475 nm. PPO activity was significantly related with grain characteristics, including 1000-kernel weight and grain colors. In flour characteristics, PPO activity positively correlated with ash and protein content (r = 0.658, P < 0.001 and r = 0.424, P < 0.05, respectively) and negatively correlated with L* value of flour (r = 0.412, P < 0.05). In the changes of color of noodle dough sheet, L* and b* values consistently decreased and a* value increased during storage. PPO activity negatively correlated with L* value of noodle dough sheet during storage (r = 0.566, P < 0.01 at 2 hr, r = 0.547, P < 0.01 at 24 hr, and r = 0.509, P < 0.01 at 48 hr). But, no significant relationship was found in between PPO activity, a* and b* values during storage. The 52 Korean wheat lines examined in this study were divided into 3 different groups, low (< 0.500), medium (0.501-0.999) and high level (> 1.000), on the basis of the level of PPO activity. Twenty two Korean wheat lines showed low level of PPO activity and Suwon 252, 277 and 280 showed lower PPO activity (< 0.200) than others.

본 연구는 적변 유발 세균에 의해 발생하는 적변삼과 polyphenol 및 polyphenol oxidase 활성과의 관계를 조사하였으며, 이는 다음과 같다. 1. 적변 유발 균주를 상처낸 건전 인삼 외피에 접종하여 무처리구와 비교하였을 때, 접종일수의 증가에 따라 Hue angle값이 접종 후 1일 101.2, 10일 95.9, 20일 90.1, 30일 60.9로 적색으로 변화되었다. 2. Lysobacter gummosus, Pseudomonas veronii 및 Agrobacterium tumefaciens 균주를 인삼의 상처부위에 접종하였을 때, 총페놀의 함량은 일수가 경과할수록 증가하였다. 3. Lysobacter gummosus, Pseudomonas veronii 및 Agrobacterium tumefaciens 균주를 상처낸 인삼에 접종하였을 때 페놀함량의 증가와 함께 효소의 활성이 증가하였으나 단백질당 PPO의 활성은 감소하였다.

우엉 뿌리(Arctium lappa L.)에서 polyphenol oxidase가 DEAE-Cellulose 음이온 수지, 황산암모늄 침전법, Phenyl-sepharose CL-4B 친화크로마토그래피 그리고 Sephadex G-100 겔여과크로마토그래피 등의 과정으로 정제되었며 정제효소의 효소학적 특성을 검토하였다. 정제된 효소의 분자량은 약 30 kDa의 단일폴리펩티드 사슬로 구성되어 있었다. 효소반응의 최적 pH와 온도는 각각 7.0과 35

The environment in which a given genotype is grown may influence its grain quality characteristics. When varieties are ~times evaluated over numerous environments, a variety environment interaction usually is observed, but the relative magnitude of environmental(E), genetic(G), and G ~times E effects on quality is unclear. In order to determine relative contribution of genotype, environment, and G ~times E interaction to the variations observed in grain quality characteristics, 18 Korean wheat cultivars and experimental lines were evaluated in two environments in 1998 and 1999. Correlation coefficients between grain quality and agronomic characteristics were also estimated. The analysis of variance for the optical density obtained by reaction bet- ween gliadin and anti-gliadin polyclonal antibody (AGPab) indicated that gliadin content measured by Enzyme-Linked Immunosorbent Assay(ELISA) was significantly in- fluenced by environment and cultivar differences. The significant differences of year and year ~times location were also found. The ratio of the variances associated with environmental effects to the variances associated with genetic effect gave relatively greater influence of environmental factor on gliadin content. The different protein content from same genotype grown in different environment might be associated with degree of storage protein accumulations. Significant relationships between ELISA and protein content, yield, ten spike weight, and ten spike number were detected. Polyphenol oxidase (PPO) activity was significantly influenced by year, location, cultivar and year ~times location. The variance in grain PPO activities among growing years appeared larger than the variation produced by the cultivar examined. This suggested that the growing environment contributed more to variability in grain PPO concentration.

The effects of wounding and jasmonic acid(JA) on polyphenol oxidase(PPO) in tomato(Lycopersicon esculentum Mill.) seedlings were investigated. PPO was strongly induced by wounding or JA, and the response was also shown to be systemically induced by wounding. Mechanical wounding in cotyledon or leaf produced a signal that caused the concentration of PPO to increase in the unwounded cotyledon, in the first leaves but not in the second leaves. Severity of wounding and light intensity also affected wound induced change in PPO activity, JA showed a stimulatory effect on the loss of chlorophyll and the rapid increase in PPO activity. The PPO was clearly more active in the wounded leaves than in controls. The potency and specificity of the JA indicate a close relationship between JA and wound-induced changes in PPO in tomato species. JA and abscisic acid(ABA) acted similarly on both unwounded and wounded leaves, but the amount of PPO in the wounded leaves was always more than the respective controls. The highest increase in PPO activity occurred in woundand JA-induced leaves of seedlings kept under bright lighting. Benzyladenine(BA) completely abolished JA- and ABA-induced PPO activity. The results suggest that JA-induced PPO activity is due to de novo PPO synthesis. Histochemical tests for PPO in stems of wound- and JA-treated tomato plants indicate that PPO was localized primarily in the outer cortex and xylem parenchyma. It is concluded that exogenously applied JA acts as stress agents and PPO may be a component of the inducible anti-hervivore defense response.