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浙江大学学报（农业与生命科学版）
Journal of Zhejiang University (Agriculture and Life Sciences)  2014, Vol. 40 Issue (6): 679-687    DOI: 10.3785/j.issn.1008-9209.2013.12.091
Food sciences     
Adsorption kinetics of tea waste to catechins.
Hu Shuqin, Tang Yi*, Liu Li
(Department of Tea Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China)
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Abstract  Catechins, the main functional components in tea, were generally recognized as possessing desirable biological and physiological effects, such as anti-oxidation, anti-cancer, reducing the risk of cardiovascular diseases etc. Therefore, application areas of tea catechins in food and pharmaceuticals were expanding rapidly. At present, conventional extraction technologies of catechins contained hot water extraction method, organic solvent extraction process, resin extraction method and supercritical CO2 extraction method. However, the application value was limited because of the low efficiency, high cost and potentially toxic residues. In order to extract catechins efficiently and safely, the recent studies found that lignocellulose could absorb catechins in abundance and in a low cost. Tea waste was used as a new kind of adsorbent in this paper. Because of the porous structure, it had large specific surface area. Meanwhile, the main components of tea waste were cellulose and protein. They all contained a mass of carboxyl groups and hydroxyl radicals which could form hydrogen bonds with catechins. The tea waste was similar to lignocellulose in structure and it was eatable, safe with no poisonous residue. The experiments were carried out as below. The equations of pseudo-first-order model and pseudo-second-order model were used to simulate the adsorption kinetics respectively. Then, different concentrations of ethanol were used to desorb the tea waste when it reached adsorption saturation. Finally, the same size tea waste was used to pack the chromatography column and the breakthrough curves of catechins and caffeine were drawn, then different concentrations of ethanol were used to elute the column gradely when it reached adsorption equilibrium. The results indicated that the kinetics were more fitted to the pseudo-second-order model (R2=0.913 60.997 1). The order of the secondary adsorption speed constant k2 was epigallocatechin gallate (EGCG) (0.000 5 g/(mg?min))

Published: 20 November 2014
CLC:  TS 272  
  S 571.1  
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Hu Shuqin
Tang Yi*
Liu Li
Cite this article:

Hu Shuqin, Tang Yi*, Liu Li . Adsorption kinetics of tea waste to catechins.. Journal of Zhejiang University (Agriculture and Life Sciences), 2014, 40(6): 679-687.

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http://www.zjujournals.com/agr/10.3785/j.issn.1008-9209.2013.12.091     OR     http://www.zjujournals.com/agr/Y2014/V40/I6/679


茶渣对儿茶素的吸附动力学

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