Papers by Author: Ming Duo Yang

Abstract: Hot water extracts from Armillaria mellea and Hohenbuehelia serotina fruit bodies were prepared and investigated for their antioxidant capacity in three different assays, namely, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, reducing power and chelating ability on ferrous ions. Among the two mushrooms hot water extracts, extract from A. mellea was better than that from H. serotina in scavenging ability and chelating effect on ferrous ions. With regard to reducing power, EC50 value of extracts from H. serotina was 0.447 mg/mL, while that of extracts from A. mellea was 1.914. From EC50 values obtained, it can be concluded that hot water extracts from A. mellea and H. serotina were good in antioxidant properties.

Abstract: Holiota nameko is an edible mushroom widely cultivated in the northeast of China. The cold water, hot water and ethanol extracts were prepared and their antioxidant properties were studied. At 2 mg/mL, the cold water extract showed a high reducing power of 1.502, whereas those of hot water and ethanol extracts were 0.868 and 0.159. With regard to the scavenging ability on DPPH free radicals, extracts were effective in the order: cold water > hot water > ethanol extracts. EC50 values for chelating ability on ferrous ions for cold water, hot water, and ethanol extracts were 1.461, 0.663, and 11.791 mg/mL, respectively. Based on EC50 values, the water extracts of P. nameko were effective antioxidants.

Abstract: 50% (V/V) ethanol extract from laoying tea (Litsea coreana Level.) was fractionated by liquid-liquid partition using ethyl acetate, n-butanol and water, respectively. The activities of nitrite scavenging (NS) and nitrosamine formation inhibiting (NFI) of three different fractions have been investigated in vitro systems. In the above assays, all the fractions showed NS and NFI potentials to varying degrees. With regard to NS activity, fractions were effective in the order: ethyl acetate > n-butanol > water fraction. EC₅₀ values for inhibiting ability on nitrosamine formation for ethyl acetate, n-butanol and water fraction were 0.170, 0.554 and 0.725 mg/mL, respectively. Total flavonoids could be the major NS and NFI components and were in the order: ethyl acetate > n-butanol > water fraction. Based on EC₅₀ values, laoying tea especially ethyl acetate-soluble fraction may have a preventive effect against carcinogenesis induced by nitrosamines.

Abstract: The modification of the pretreated wheat bran by extrusion technology and cellulose enzyme method was studied to improve the content of soluble dietary fiber and enhance product functionality. First ,the pretreated dietary fiber (DF1) was modified by extrusion technology to get DF2,then DF2 were modified by enzymolysis of cellulose enzyme . The results showed as fowllow: the optimum conditions for extrusion modification was 45% material moisture content, 25 r•min^-1 feeding speed, 200 r•min-1screw speed, 70-90-110-130-150°Cextrusion temperature, and the SDF content of DF2 is 33.95%. the optimal enzymatic modification conditions for DF2 was 1:0solid-liquid ratio, 30U/g enzyme adding, 4h enzymatic hydrolysis time.

Abstract: Differences in physicochemical properties of starch isolated from red bean and mung bean, including chemical composition, amylose content, starch granule morphology, swelling power and solubility, thermal properties and freeze-thaw stability were compared. There was no significant difference on the chemical compositions between the two starches. Most of the granules of red bean starch was oval or elliptical, the diameter was between 9.54 μm-30.98μm, the granules from mung bean starch was round or oval, the diameter was between 10.50 μm-27.59μm; The extent of solubility in mung bean starch was significantly higher than red bean starch between 60 and 90°C, the temperature that the swelling power began to increase obviously of mung bean starch was higher than that of red starch at 60 to 90°C. T_o, T_p, T_c andΔH of red bean starch were higher than that of mung bean.

Abstract: Laoying Tea, leaves of Litsea coreana L., is conventionally consumed as healthy tea beverage in southern China for hundreds of years. The ethanolic, cold water and hot water extracts were prepared and their antioxidant properties studied. At 160 µg/mL, the cold water extract showed a high reducing power of 1.056. With regard to the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals, extracts were effective in the order: ethanolic > cold water > hot water extracts. EC₅₀ values for chelating ability on ferrous ions for ethanolic, cold water and hot water extracts were 10.23, 0.85 and 1.12 mg/mL, respectively. Total phenols were the major naturally occurring antioxidant components found and were in the order: cold water > hot water > ethanolic extracts. Based on EC₅₀ values, the various extracts from laoying tea were effective antioxidants.

Abstract: Chroogomphis rutillus is an ectomycorrhizal edible mushroom available in China. The ethanolic, cold water and hot water extracts were prepared and their antioxidant properties studied. At 4 mg/mL, the ethanolic extract showed a high reducing power of 1.561, whereas those of cold water and hot water extracts were 1.161 and 0.808. With regard to the scavenging ability on 1,1-diphenyl-2-picrylhydrazyl radicals, extracts were effective in the order: ethanolic > cold water > hot water extracts. EC₅₀ values for chelating ability on ferrous ions for ethanolic, cold water and hot water extracts were 15.755, 0.059, and 0.067 mg/mL, respectively. Based on EC₅₀ values, the various extracts from C. rutillus were effective antioxidants.

Abstract: Mung bean grows widely in the world, and is the good source of mung bean starch, which contains higher content of amylose and has special gelling properties. Isolation methods, molecular structure (x-ray pattern) and important physiochemical properties of mung bean starch and influencing factors in recent studies were reviewed, which is helpful for the further and comprehensive use of mung bean starch.