title: Exposure assessment of lovastatin in Pu-erh tea.
abstract: This paper reports the results of an extensive survey on the levels of lovastatin in Pu-erh tea samples. The microbial source of lovastatin was assessed by testing the ability of fungi with higher isolation frequency in the Pu-erh tea samples to produce lovastatin on Czapek yeast extract agar (CYA). Lovastatin was not detected in any of the raw Pu-erh tea samples without storage but was found in almost all the ripe Pu-erh tea samples, with lovastatin contents ranging from 20.61 ng/gdw to 226.38 ng/gdw. After five years' storage, the lovastatin levels increased obviously in ripe Pu-erh tea samples and 55% of raw Pu-erh tea samples from 2007 were found to contain lovastatin with concentrations ranging between 28.41 ng/gdw and 228.61 ng/gdw. With increasing storage time, lovastatin concentration in ripe Pu-erh tea, and the occurrence and concentration of lovastatin for raw Pu-erh tea increased significantly. Three genera of fungi: Aspergillus, Penicillium and Trichoderma were often isolated from Pu-erh tea samples. A total of 40 strains from 3 fungal genera were selected to test their ability to produce lovastatin. Only 6 strains, Aspergillus tubingensis, Aspergillus wentii, Aspergillus fumigatus, Penicillium chrysogenum, Trichoderma asperellum and Trichoderma citrinoviride, were able to produce lovastatin reaching concentrations of 9.59 ± 0.42 ng/g CYA, 2.33 ± 0.21 ng/g CYA, 2.77 ± 0.13 ng/g CYA, 3.36 ± 0.69 ng/g CYA, 4.8 ± 0.17 ng/g CYA, and 1.47 ± 0.36 ng/g CYA respectively in Czapek yeast extract agar.
authors.affiliation: College of Horticulture and Landscape Architecture, Yangtze University, Jingzhou, Hubei 434025, PR China. zzjswu@126.com
authors.forename: Zhen-Jun
authors.initials: ZJ
authors.lastname: Zhao
authors.forename: You-Zhao
authors.initials: YZ
authors.lastname: Pan
authors.forename: Qin-Jin
authors.initials: QJ
authors.lastname: Liu
authors.forename: Xing-Hui
authors.initials: XH
authors.lastname: Li
mesh_terms: D005511:Food Handling; D005516:Food Microbiology; D005658:Fungi / Q000302:isolation & purification / Q000378:metabolism; D008148:Lovastatin / Q000032:analysis* / Q000096:biosynthesis; D013662:Tea / Q000737:chemistry* / Q000382:microbiology*; D013997:Time Factors
chemical_list: D013662:Tea; D008148:Lovastatin