Enzymatic improvement in the polyphenol extractability and antioxidant activity of green tea extracts

Yang Hee Hong, Eun Young Jung, Yooheon Park, Kwang Soon Shin, Tae Young Kim, Kwang Won Yu, Un Jae Chang, Hyung Joo Suh

Research output: Contribution to journalArticlepeer-review

47 Citations (Scopus)


This study describes increases in extraction efficiency and the bioconversion of catechins after treatment with several commercial enzymes. Tannase was also used to improve the anti-radical activities of green tea extracts. Enzymatic treatment with various commercial enzymes was introduced to improve the extraction efficiency of polyphenols. The total polyphenol, flavonoid, and catechin contents and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the green tea extract treated with Viscozyme (VG) were significantly higher than those treated with other commercial enzymatic extractions (p < 0:05). More than 95% of the epigallocatechingallate (EGCG) and of the epicatechingallate (ECG) was hydrolyzed to epigallocatechin (EGC) and to epicatechin (EC) in successive 20 min treatments with Viscozyme and tannase (TG). Due to its hydrolytic activity, treatment involving tannase resulted in a significant release of gallic acid (GA), EGC, and EC, leading to greater radical scavenging activities. Regarding the IC50 values of the DPPH and 2,2-azino-di-(3- ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, the green tea extract treated with TG showed values of 131.23 and 28.83μg/mL, VG showed values of 224.70 and 32.54μg/mL, and normal green tea extract (NG) showed values of 241.11 and 66.27μg/mL, respectively. These results indicate that successive treatment with Viscozyme and tannase improves the extraction efficiency of polyphenols and increases radical scavenging activities.

Original languageEnglish
Pages (from-to)22-29
Number of pages8
JournalBioscience, Biotechnology and Biochemistry
Issue number1
Publication statusPublished - 2013

Bibliographical note

Funding Information:
This research was supported by the Technology Development Program for Food, of the Ministry for Food, Agriculture, Forestry, and Fisheries of the Republic of Korea.


  • Antioxidant
  • Extractability
  • Green tea
  • Tannase
  • Viscozyme

ASJC Scopus subject areas

  • Biotechnology
  • Analytical Chemistry
  • Biochemistry
  • Applied Microbiology and Biotechnology
  • Molecular Biology
  • Organic Chemistry


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