• Food Science and Biotechnology
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• v.16 no.6
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• pp.935-942
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• 2007

The stem bark of Rhus verniciflua (RVSB) has been used in herbal medicine to treat diabetes mellitus and stomach ailments for thousands of years in Korea, despite its content of the plant allergen, urushiol. A new biological approach for the removal of urushiol from RVSB using mushrooms is described. All mushroom species (11 sp.) employed in this study were able to grow on RVSB, although the growth rate (mm/day) was lower than the control (sawdust). The components of urushiol congeners [C15 triene (m/z 314), C15 diene (m/z 316), C15 monoene (m/z 318), and C15 saturated (m/z 320)] were purified by HPLC and identified by GC-MS. A C15:3 (3-pentadecatrienly catechol) was found to be most abundant in RVSB. Urushiol analogues decreased remarkably from 154.15 to 10.73 mg/100 g (approximately 93%) by Fomitella fraxinea, whereas Trametes vercicolor showed only a 1.46% degradation capacity despite its 2 fold higher growth rate. Similarly, laccase activity was found to be high for F. fraxinea and low for T. vercicolor. Moreover, approximately 98% detoxification was accomplished by F. fraxinea cultivated on RVSB supplemented with 20%(w/w) rice bran. These findings suggest that mushrooms can be used in the detoxification of RVSB.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.7
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• pp.927-933
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• 2008

The quality of Gangjung added with detoxified stem bark of Rhus verniciflua (RVSB) extract ($0{\sim}7%$, w/w) during room temperature storage ($25^{\circ}C$, 60 days) was investigated. The moisture content of Gangjung slightly decreased as the storage period increased, especially Gangjung at concentrations between $0{\sim}1%$, $3{\sim}5%$, and 7% decreased after 30, 40 and 50 days of storage, respectively. No significant differences in the hardness were found among the control and experimental samples. However, the peak number of Gangjung containing detoxified RVSB extract at concentrations of $0{\sim}3%$ significantly decreased after 60 days of storage, while that of Gangjung with 5% and 7% addition were not changed during storage. The acid, peroxide and TBA values of Gangjung increased as the storage period increased but the acid value was significantly lower for the Gangjung prepared with 7% (w/w) detoxified RVSB extract after 40 days of storage. Moreover, from 40 to 60 days of room temperature storage, peroxide value significantly decreased as the concentrations of detoxified RVSB extract increased and TBA value significantly decreased when the addition of detoxified RVSB extract was over 3% (w/w). These results suggest that the physical texture of Gangjung improved and lipid oxidation was reduced by the addition of detoxified RVSB extract.