Comparison of the free and bound phenolic profiles and cellular antioxidant activities of litchi pulp extracts from different solvents

BMC Complementary and Alternative Medicine

Research Article

Fangli Hou¹  Dongxiao Su²  Fei Huang²  Mingwei Zhang³  Jinxin Guo³  Ruifen Zhang³  Yuanyuan Deng³  Zhencheng Wei³ 

[1] College of Food Science, Guangdong Pharmaceutical University, 528458, Zhongshan, P.R. China;Department of Food Science and Technology, Huazhong Agricultural University, 430070, Wuhan, P.R. China;Sericultural and Agri-food Research Institute, Guangdong Academy of Agricultural Sciences, 510610, Guangzhou, P.R. China;Sericultural and Agri-food Research Institute, Guangdong Academy of Agricultural Sciences, 510610, Guangzhou, P.R. China;

关键词: Phenolic Compound;    Rutin;    Total Phenolic Content;    Alkaline Hydrolysis;    Vanillic Acid;   

DOI  :  10.1186/1472-6882-14-9

 received in 2013-09-04, accepted in 2013-12-18,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundThe phenolic contents and antioxidant activities of fruits could be underestimated if the bound phenolic compounds are not considered. In the present study, the extraction efficiencies of various solvents were investigated in terms of the total content of the free and bound phenolic compounds, as well as the phenolic profiles and antioxidant activities of the extracts.MethodsFive different solvent mixtures were used to extract the free phenolic compounds from litchi pulp. Alkaline and acidic hydrolysis methods were compared for the hydrolysis of bound phenolic compounds from litchi pulp residue. The phenolic compositions of the free and bound fractions from the litchi pulp were identified using HPLC-DAD. The antioxidant activities of the litchi pulp extracts were determined by oxygen radical absorbance capacity (ORAC) and cellular antioxidant activity (CAA) assays.ResultsOf the solvents tested, aqueous acetone extracted the largest amount of total free phenolic compounds (210.7 mg GAE/100 g FW) from litchi pulp, followed sequentially by aqueous mixtures of methanol, ethanol and ethyl acetate, and water itself. The acid hydrolysis method released twice as many bound phenolic compounds as the alkaline hydrolysis method. Nine phenolic compounds were detected in the aqueous acetone extract. In contrast, not all of these compounds were found in the other four extracts. The classification and content of the bound phenolic compounds released by the acid hydrolysis method were higher than those achieved by the alkaline hydrolysis. The aqueous acetone extract showing the highest ORAC value (3406.9 μmol TE/100 g FW) for the free phenolic extracts. For the CAA method, however, the aqueous acetone and methanol extracts (56.7 and 55.1 μmol QE/100 g FW) showed the highest levels of activity of the five extracts tested. The ORAC and CAA values of the bound phenolic compounds obtained by acid hydrolysis were 2.6- and 1.9-fold higher than those obtained using the alkaline hydrolysis method.ConclusionsThe free and bound phenolic contents and profiles and antioxidant activities of the extracts were found to be dependent on the extraction solvent used. Litchi exhibited good cellular antioxidant activity and could be a potentially useful natural source of antioxidants.

【 授权许可】

Unknown   
© Su et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.