• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.265-275
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• 2002

Flavonoid biosynthesis is one of the most extensively studied areas in the secondary metabolism. Due to the study of flavonoid metabolism in diverse plant system, the pathways become the best characterized secondary metabolites and can be excellent targets for metabolic engineering. These flavonoid-derived secondary metabolites have been considerably divergent functional roles: floral pigment, anticancer, antiviral, antitoxin, and hepatoprotective. Three species have been significant for elucidating the flavonoid metabolism and isolating the genes controlling the flavonoid genes: maize (Zea mays), snapdragon (Antirrhinum majus) and petunia (Prtunia hybrida). Recently, many genes involved in biosynthesis of flavonoid have been isolated and characterized using mutation and recombinant DNA technologies including transposon tagging and T-DNA tagging which are novel approaches for the discovery of uncharacterized genes. Metabolic engineering of flavonoid biosynthesis was approached by sense or antisense manipulation of the genes related with flavonoid pathway, or by modified expression of regulatory genes. So, the use of a variety of experimental tools and metabolic engineering facilitated the characterization of the flavonoid metabolism. Here we review recent progresses in flavonoid metabolism: confirmation of genes, metabolic engineering, and applications in the industrial use.

• Food Science and Preservation
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• v.23 no.1
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• pp.49-56
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• 2016

This study analyzed the physicochemical characteristics of Astragalus membranaceus (AM) fermented with seven different mushroom mycelia. Physicochemical characteristics, such as contents of moisture, pH, total reducing sugars, free sugar, and isoflavonoid, were investigated. The moisture content was increased in most of the samples. The pH values of AM fermented with Phellinus linteus and Flammulina velutipes were increased, while the pH of other samples were similar to that of non-fermented AM. The reducing sugar content was in the range of 211.69~391.74 mg/100 g. The extraction yield using water was higher than that when extracted with 80% ethanol. The free sugar content was increased through fermentation with mushroom mycelia. However, the glucose contents of the 80% ethanol and water extracts were decreased. Finally, the calycosin and formononetin contents in 80% ethanol and water extracts of AM fermented with Phellinus linteus were 2,549.24 mg/g, and 827.66 mg/g for calycosin, and 1,366.69 mg/g and 221.28 mg/g for formononetin, respectively. These results suggest that fermentation with mushroom mycelia could be used to increase the bioactivity of AM. The mycelium-fermented AM might be a valuable source of functional material and edible resource for industry.

• Food Science and Preservation
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• v.23 no.5
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• pp.680-688
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• 2016

This study analyzed the changes in physicochemical components of Astragalus membranaceus (AM) fermented with Phellinus linteus. Moisture content, pH, total acidity, total reducing sugar content, extraction yield, free sugar content, free amino acid and isoflavonoid (calycosin, formononetin) were investigated. The moisture content was increased during fermentation with Phellinus linteus. The pH level increased while the total acidity significantly decreased during fermentation. The reducing sugar content were in the range of 0.32~0.61%. The extraction yield using water was higher than that using 80% ethanol. The major free sugars were identified as glucose, fructose, sucrose and the content of free sugars decreased through fermentation. However, the glucose and sucrose contents of the water extracts were increased. In addition, the free amino acid increased significantly during fermentation. Finally, calycosin and formononetins contents in water extracts of after 30 days of AM fermentaion with Phellinus linteus were (3.91 mg/100 g) and (1.38 mg/100 g), respectively. These results suggest that fermentation with Phellinus linteus could be used to increase the bioactivity of AM. The mycelium-fermented AM could be a valuable source of functional material and edible resource for industry.