Genes cloning, sequencing and function identification of recombinant polyphenol oxidase isozymes for production of monomeric theaflavins from Camellia sinensis

Article Food Science & Technology

In vitro enzymatic synthesis of a monomeric theaflavin using a polyphenol oxidase isozyme from tea (Camellia sinensis) leaf

Jie Teng et al.

Summary: This study successfully synthesized monomeric theaflavins by purifying the PPOI isozyme, providing further insight into the important role of PPO in tea production.

INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY (2022)

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Article Food Science & Technology

Cloning, sequencing and structural analysis of membrane-bound polyphenol oxidase from Granny Smith apples (Malus x domestica Borkh)

Qian-Yun Han et al.

Summary: The gene sequence of membrane-bound polyphenol oxidase (mPPO) was successfully cloned using PCR method, revealing a highly conserved di-copper binding region. The three-dimensional structure of mPPO showed two catalytic copper ions coordinated with histidine residues, with smaller ligands exhibiting higher affinity. Molecular dynamic simulation highlighted the significance of Phe 353 in influencing enzymatic activity through substrate coordination in the active site.

INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY (2022)

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Article Biotechnology & Applied Microbiology

Optimization of enzymatic synthesis of theaflavins from potato polyphenol oxidase

Dong Li et al.

Summary: In this study, the synthesis of theaflavins using polyphenol oxidase catalysis was investigated. The optimal synthesis conditions were determined, and the dynamic changes and correlations of the main substrates and products were analyzed. This study lays a foundation for the industrial production of theaflavins.

BIOPROCESS AND BIOSYSTEMS ENGINEERING (2022)

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Article Chemistry, Applied

Improved yield of theaflavin-3,3′-digallate from Bacillus megaterium tyrosinase via directed evolution

Jinghui Zhou et al.

Summary: Theaflavin-3,3'-digallate (TFDG) from black tea has various health benefits, but its application is limited due to low yields. In this study, tyrosinases from Bacillus megaterium were used to synthesize TFDG through directed evolution and high-throughput screening. Mutant Bmtyrc-3 showed significantly improved catalytic efficiency and higher production of TFDG. The broader substrate binding area of Bmtyrc-3 resulted in increased activity of substrates EGCG and ECG.

FOOD CHEMISTRY (2022)

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Review Food Science & Technology

Metabolomics in quality formation and characterisation of tea products: a review

Hongli Cai et al.

Summary: This article summarizes the application of metabolomics in tea, including the main metabolites in tea and their implications on tea quality, research on optimizing tea processing steps, and methods to distinguish different grades of tea through metabolomics. These studies provide guidance for improving tea quality and highlight potential challenges.

INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY (2022)

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Article Multidisciplinary Sciences

Molecular characterization of polyphenol oxidase between small and large leaf tea cultivars

Chung-Tse Chen et al.

Summary: This study compared the molecular properties of CsPPO between two tea varieties and clarified the physiological role of PPO in tea. The results indicated that the harvest season and altitude affected the CsPPO transcript level, and temperature had a more significant regulatory effect on CsPPO in the small-leaf variety.

SCIENTIFIC REPORTS (2022)

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Article Food Science & Technology

Influence of enzyme source and catechins on theaflavins formation during in vitro liquid-state fermentation

Jinjie Hua et al.

Summary: The study optimized the production of TFs from catechins in vitro using different enzyme sources and addition timings. It was found that using PPO as an enzyme source and batchwise addition of catechins can improve the formation of TFs, especially with a 1:2 ratio of EGC/EGCG. This research provides insights into the mechanisms of TFs synthesis.

LWT-FOOD SCIENCE AND TECHNOLOGY (2021)

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Article Chemistry, Applied

Polyphenol oxidase dominates the conversions of flavonol glycosides in tea leaves

Xiao-Yuan Guo et al.

Summary: The study revealed that PPO plays a significant role in catalyzing flavonol glycosides in tea leaves, with the addition of POD enhancing the oxidation process. Myricetin glycosides showed the highest sensitivity to PPO, and sugar moieties enhanced the binding affinity of flavonol glycosides for PPO.

FOOD CHEMISTRY (2021)

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Article Chemistry, Applied

Exploring the biochemical properties of three polyphenol oxidases from blueberry (Vaccinium corymbosum L.)

Yulong Wei et al.

Summary: The first purification of three PPOs from blueberries was achieved, with their optimal conditions and activity changes under different treatments being discovered. Additionally, the binding of substrate to catalytic cavity was found to be related to certain amino acid residues.

FOOD CHEMISTRY (2021)

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Article Food Science & Technology

Antioxidant capacity and characteristics of theaflavin catechins and ginger freeze-dried extract as affected by extraction techniques

Ali Imran et al.

Summary: The study found that ultrasound extraction technique was more effective in extracting polyphenols from green tea, black tea, and ginger. Green tea showed better antioxidant performance compared to other varieties, with ethanol being the preferred solvent. Isolates demonstrated higher antioxidant potential than extracts, with catechins showing the highest effectiveness.

INTERNATIONAL JOURNAL OF FOOD PROPERTIES (2021)

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Article Food Science & Technology