• Title/Summary/Keyword: Polyphenoloxidase Activity (PPO)

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Studies on Antimutagenic Effects and Gene Repair of Enzymatic Browning Reaction Products (효소적 갈변반응 생성물의 돌연변이 억제효과 및 유전자 수복에 관한 연구)

  • Ham, Seung-Shi;Kim, Sung-Wan;Kim, Young-Myung
    • Korean Journal of Food Science and Technology
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    • v.22 no.6
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    • pp.632-639
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    • 1990
  • The biological activities of twelve different kinds of enzymatic browning reaction products(EBRP), which resulted from the reactants four kinds of polyphenols with polyphenol oxidase extracted from Ligularia fischeri, pimpinella brachycarpa and Aster scaber of edible mountain herbs. All of twelve samples did not show any mutagenic effect in the spore rec-assay, Ames mutagenicity test and DNA breaking test. However metal ions such as $Cu^{2+},\;Fe^{2+}$, and $Ni^{2+}$ were increased the DNA breakage in rec-assay. The EBRPs inhibited the mutagenicities induced by $benzo({\alpha})pyrene (B({\alpha})P)$, 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b]indole(Trp-P-1) and 2-aminofluorene(2-AF) in Salmonella/microsome assay system with S-9 mix. In effects of EBRPs on the DNA repair system, the activity of EcoRI was highly inhibited and that of $T_{4}$ DNA ligase was inactivated by addition of EBRPs. The results of transformation ratio of plasmid pGA658 into E. coli HB 101 was significantly decreased by the reaction products of S. brachycarpa polyphenoloxidase (PPO). When UV light was exposed to the mixture of DNA and EBRP before the thanformation, the reaction products from L. fischeri PPO with pyrogallol, catechol and hydroxyhydroquinone stimulated transformation ratio.

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Effects of Processing Temperature and Browning Inhibitor on Quality Properties of Fresh-cut Burdock Roots (가공 온도 및 갈변 억제제가 신선절단 우엉의 품질 특성에 미치는 영향)

  • Chung, Hun-Sik;Seong, Jong-Hwan;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.19 no.1
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    • pp.31-36
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    • 2012
  • Fresh-cut burdock roots were processed at 4 and $25^{\circ}C$, respectively. The fresh-cut burdock roots were treated with different browning inhibitors (3% citric acid, 3% sodium chloride, 0.3% cystein, and 3% sodium acetate solutions), and the changes in their quality and browning characteristics were investigated. The respiration rate and browning index of the cut roots prepared at $4^{\circ}C$ were lower than those of the cut roots prepared at $25^{\circ}C$. The soluble solid content was higher in the cut roots prepared at $4^{\circ}C$ than in those prepared at $25^{\circ}C$. The weight loss and flesh firmness were not affected by the processing temperatures. Among the browning inhibitors, 0.3% cystein showed the best browning-retarding effect. There was no difference in phenolic compound content between the browning-inhibitor-treated roots and the nontreated roots, but the PPO activity was higher in the latter than in the former. Therefore, the processing temperatures of fresh-cut burdock roots affected their quality and browning development, and the combination of a low processing temperature and the use of the proper browning inhibitor should be applied for the higher quality of the produce.