Loading...

Producing l-theanine from Liquid Waste Obtained from Tea Polyphenol Production(and Biosynthesis of Theanine by Glutaminase)

Sakhaei, Minoo | 2017

674 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 49923 (03)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Alemzadeh, Iran
  7. Abstract:
  8. Theanine is a non-protein amino acid which was first isolated from tea plant leaves (Camellia sinensis) and also found in a mushroom named Xerocomus badius and some other Camellia species such as C.japonica and C.sasanqua. Theanine comprises about 50% of amino acids in tea and 1-2% of dry weight of tea leaves. It contributes to the umami taste and unique flavor to tea infusion and has many physiological and pharmaceutical effects such as anti-tumor and anti-cancer activity, neuroprotection, antihypertensive, relaxation, increased focus and anti-obesity effects. So this compound is essential for human body but is not synthesized in it and should be administrated orally. In recent years, study of different synthesis methods and pharmaceutical effects of theanine have achieved much attention. In present study, at first we used a two-phase method to extract theanine. For this purpose hot water (60 ℃) was added to crudely crushed tea leaves so that tea compound were entered to water. Then, in a two-step liquid-liquid extraction the above mixture filtrate was decaffeinated and its polyphenols were extracted from Decaffeinated Crude Extract. In next step, solutions with certain concentrations of SDS (anionic surfactant) and CTAB (cationic surfactant) were prepared separately by adding SDS and CTAB to the mentioned liquid. The two solutions were mixed at certain proportions and shaken for some time and was stand for phase separation at constant temperature. In spite of repeating the experiments, two-phase system was not formed and desired result was not achieved. Thus, the method changed. In the second method, Solid state fermentation (SSF) was carried out for the production of L-glutaminase by the fungal strain Trichoderma koningii using sesamum oil cake as the solid substrate. Biosynthesis of theanine was performed in presence of extracted enzyme solution and ethylamine and L-glutamine as substrates. theanine production reaction, the hydrolysis reaction of L-glutamine in presence of L-glutaminase enzyme solution happenedas an undesirable one. In theanine synthesis reaction the effective parameters, namely as Glutamine and ethylamine concentration and volume of enzyme solution on theanine production were evaluated based on response surface methodology coupled with central composite design. The highest theanine concentration was obtained 43 mM at ethylamine concentration of 0.9 M, glutamine concentration of 0.3 M and enzyme solution of 3 mlit
  9. Keywords:
  10. Polyphenols ; Enzymatic Synthesis ; Theanine ; Glutaminase ; Trichoderma Koningii

 Digital Object List

 Bookmark

No TOC