Research Article Open Access

Characterization of Crude Polyphenol Oxidase Activity in Buckwheat Sprouts

Yuedong Song1, Yangfang Zhang1, Yilin Wang1, Jin Zhang1, Fei Wang1, Guanglei Chu2, Haifang Xiao1 and Xia Sun1
  • 1 Shandong University of Technology, China
  • 2 Shandong Provincial Engineering Research Center of Vegetable Safety and Quality Traceability, China

Abstract

Buckwheat sprouts can not only effectively reduce the trypsin inhibitor in buckwheat grain, but also improve the content of bioactive ingredients such as flavonoids and other effective components. However, Polyphenol Oxidase (PPO) in buckwheat sprouts causes browning of food, which limits the application of buckwheat sprouts in food. In addressing this problem, studying the characteristics of PPO in buckwheat sprouts is necessary. PPO in buckwheat sprouts was first studied by germinating buckwheat sprouts as raw material for 10 days. Results showed that the optimum temperature and pH of PPO in buckwheat sprouts were 32°C and 7.2, respectively. PPO had specificity to substrates. The catalytic capacity of PPO with pyrogallic acid was higher than that of catechol, which had weak catalytic capacity of hydroquinone and resorcinol and no catalytic capacity to gallic acid. PPO showed strong thermal stability because its relative activity remained 23.1%±1.69% even heating at 90°C for 30 min. Ascorbic acid, L-cysteine, sodium hydrogen sulfite and sodium sulfite all had significant inhibition effect on PPO activity. The best inhibitor was ascorbic acid, whereas citric acid and Ethylenediaminetetraacetic acid disodium salt had no evident effect. The PPO activity was inhibited at a low concentration of Cu2+ and Mg2+ (0-1 mm) and it can be significantly activated at a higher concentration (5-50 mm) by adding AL3+, whereas no significance was observed when adding Ca2+. This study can provide reliable theoretical support for avoiding browning of buckwheat sprouts during food processing.

American Journal of Biochemistry and Biotechnology
Volume 17 No. 2, 2021, 281-289

DOI: https://doi.org/10.3844/ajbbsp.2021.281.289

Submitted On: 7 February 2021 Published On: 25 June 2021

How to Cite: Song, Y., Zhang, Y., Wang, Y., Zhang, J., Wang, F., Chu, G., Xiao, H. & Sun, X. (2021). Characterization of Crude Polyphenol Oxidase Activity in Buckwheat Sprouts. American Journal of Biochemistry and Biotechnology, 17(2), 281-289. https://doi.org/10.3844/ajbbsp.2021.281.289

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Keywords

  • Polyphenol Oxidase
  • Buckwheat Sprouts
  • Enzyme Characteristics
  • Kinetic Characteristics
  • Inhibitor