title: Transformation of Litchi Pericarp-Derived Condensed Tannin with Aspergillus awamori.
abstract: Condensed tannin is a ubiquitous polyphenol in plants that possesses substantial antioxidant capacity. In this study, we have investigated the polyphenol extraction recovery and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity of the extracted polyphenol after litchi pericarp is treated with Aspergillus awamori, Aspergillus sojae or Aspergillus oryzae. We have further explored the activity of A. awamori in the formation of condensed tannin. The treatment of A. awamori appeared to produce the highest antioxidant activity of polyphenol from litchi pericarp. Further studies suggested that the treatment of A. awamori releases the non-extractable condensed tannin from cell walls of litchi pericarp. The total extractable tannin in the litchi pericarp residue after a six-time extraction with 60% ethanol increased from 199.92 ± 14.47-318.38 ± 7.59 μg/g dry weight (DW) after the treatment of A. awamori. The ESI-TOF-MS and HPLC-MS² analyses further revealed that treatment of A. awamori degraded B-type condensed tannin (condensed flavan-3-ol via C4-C8 linkage), but exhibited a limited capacity to degrade the condensed tannin containing A-type linkage subunits (C4-C8 coupled C2-O-C7 linkage). These results suggest that the treatment of A. awamori can significantly improve the production of condensed tannin from litchi pericarp.
authors.affiliation: Key Laboratory of Plant Resource Conservation and Sustainable Utilization/Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China. youhulinsen@hotmail.com.
authors.forename: Sen
authors.initials: S
authors.lastname: Lin
authors.affiliation: Wenzhou Institute of Biomaterials and Engineering (in Preparation), Chinese Academy of Science, Wenzhou 325000, China. liqing@wibe.ac.cn.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.affiliation: Key Laboratory of Plant Resource Conservation and Sustainable Utilization/Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China. yangbao@scbg.ac.cn.
authors.forename: Bao
authors.initials: B
authors.lastname: Yang
authors.affiliation: Key Laboratory of Plant Resource Conservation and Sustainable Utilization/Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China. xwduan@scbg.ac.cn.
authors.forename: Xuewu
authors.initials: X
authors.lastname: Duan
authors.affiliation: Sericultural &amp; Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China. mwzhh@163.net.
authors.forename: Mingwei
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Guelph Research and Development Center, Agriculture and Agri-Food Canada, Guelph, ON N1G 5C9, Canada. john.shi@agr.gc.ca.
authors.forename: John
authors.initials: J
authors.lastname: Shi
authors.affiliation: Key Laboratory of Plant Resource Conservation and Sustainable Utilization/Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China. ymjiang@scbg.ac.cn.
authors.forename: Yueming
authors.initials: Y
authors.lastname: Jiang
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001230:Aspergillus / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D005638:Fruit / Q000737:chemistry / Q000378:metabolism; D032125:Litchi / Q000737:chemistry* / Q000378:metabolism; D013058:Mass Spectrometry; D059808:Polyphenols / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D013634:Tannins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D059808:Polyphenols; D013634:Tannins
keywords: A. awamori; antioxidant activity; condensed tannin; litchi pericarp; transformation