为了提高树莓粉理化性质和抗氧化性质,以麦芽糊精为助干剂,考查喷雾干燥条件对树莓粉理化指标和抗氧化指标的影响。结果表明:进风温度(190~230℃)、麦芽糊精添加量(70%~110%,按照树莓汁固形物计算)、热空气流量(0.66~1.10 m3/min)、进料...为了提高树莓粉理化性质和抗氧化性质,以麦芽糊精为助干剂,考查喷雾干燥条件对树莓粉理化指标和抗氧化指标的影响。结果表明:进风温度(190~230℃)、麦芽糊精添加量(70%~110%,按照树莓汁固形物计算)、热空气流量(0.66~1.10 m3/min)、进料量(2.67~8 m L/min)对树莓粉的理化性质和抗氧化性质产生显著的影响,树莓粉得率、堆积密度、溶解时间、红度值和黄度值都呈现升高趋势,含水率、亮度值、总酚浓度、(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率、超氧自由基清除率、羟自由基清除率都呈现下降的趋势。并且,麦芽糊精添加量110%,树莓粉得率、总酚浓度和抗氧化能力显著增加,然而进风温度220℃、热空气流量0.99 m3/min和进料量6.67 m L/min使树莓粉得率升高时,其总酚浓度和抗氧化能力均显著降低(P<0.05)。展开更多
Wheat germ protein hydrolysates were prepared by protease hydrolysis, ultrafiltration and dynamical adsorption of resin. The total amount of amino acids in 100 g wheat germ protein hydrolysates is 93.95 g. Wheat germ ...Wheat germ protein hydrolysates were prepared by protease hydrolysis, ultrafiltration and dynamical adsorption of resin. The total amount of amino acids in 100 g wheat germ protein hydrolysates is 93.95 g. Wheat germ protein hydrolysates are primarily composed of 4 fractions: 17.78% in the relative molecular mass range of 115631512, 17.50% in 1512842, 27.38% in 842372 and 30.65% in 37276, respectively. The antioxidant properties of wheat germ protein hydrolysates were evaluated by using different antioxidant tests in vitro. 1.20 g/L wheat germ protein hydrolysates exhibit 78.75% inhibition of peroxidation in linolei acid system; and 1.6g/L wheat germ protein hydrolysates show 81.11% scavenging effect on the 1,1-diphenyl-2-picrylhrazyl radical. The reducing power of 2.50 g/L wheat germ protein hydrolysates is 0.84. Furthermore, the scavenging activity of 0.60 g/L wheat germ protein hydrolysates against superoxide radical is 75.40%; 0.50 g/L wheat germ protein hydrolysates exhibit 63.35% chelating effect on ferrous ion. These antioxidant activities of wheat germ protein hydrolsates increase with the increase of its concentration. Experimental results suggest that wheat germ protein hydrolysate is a suitable natural antioxidant rich in nutrition and nontoxic.展开更多
The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance ...The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe2O4 when content of CaO is less than 4%(mass fraction), bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 MPa, but that of the samples without CaO is only 60 MPa. Fracture toughness is improved obviously by CaO doping, the samples doped with 2% CaO have the maximum fracture toughness of 2.12 MPa ·m1/2 , which is about two times of that of the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe2O4 composite ceramics.展开更多
The high-temperature oxidation resistance behavior of 7% （mass fraction） Y203-ZrO2 thermal barrier coatings （TBCs） irradiated by high-intensity pulsed ion beam （HIPIB） was investigated under the cyclic oxidation...The high-temperature oxidation resistance behavior of 7% （mass fraction） Y203-ZrO2 thermal barrier coatings （TBCs） irradiated by high-intensity pulsed ion beam （HIPIB） was investigated under the cyclic oxidation condition of 1 050 ℃ and 1 h. The columnar grains in the TBCs disappear after the HIPIB irradiation at ion current densities of 100-200 A/cm^2 and the irradiated surface becomes smooth and densified after remelting and ablation due to the HIPIB irradiation. The thermally grown oxide （TGO） layer thickness of the irradiated TBCs is smaller than that of the original TBCs. After 15 cycles, the mass gains of the original TBCs and those irradiated by ion current densities of 100 and 200 A/cm^2 due to the oxidation are found to be 0.8-0.9, 0.6-0.7, and 0.3-0.4 mg/cm^2, respectively. The inward diffusion of oxygen through the irradiated TBCs is significantly impeded by the densified top layer formed due to irradiation, which is the main reason for the improved overall oxidation resistance of the irradiated TBCs.展开更多
文摘为了提高树莓粉理化性质和抗氧化性质,以麦芽糊精为助干剂,考查喷雾干燥条件对树莓粉理化指标和抗氧化指标的影响。结果表明:进风温度(190~230℃)、麦芽糊精添加量(70%~110%,按照树莓汁固形物计算)、热空气流量(0.66~1.10 m3/min)、进料量(2.67~8 m L/min)对树莓粉的理化性质和抗氧化性质产生显著的影响,树莓粉得率、堆积密度、溶解时间、红度值和黄度值都呈现升高趋势,含水率、亮度值、总酚浓度、(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率、超氧自由基清除率、羟自由基清除率都呈现下降的趋势。并且,麦芽糊精添加量110%,树莓粉得率、总酚浓度和抗氧化能力显著增加,然而进风温度220℃、热空气流量0.99 m3/min和进料量6.67 m L/min使树莓粉得率升高时,其总酚浓度和抗氧化能力均显著降低(P<0.05)。
文摘Wheat germ protein hydrolysates were prepared by protease hydrolysis, ultrafiltration and dynamical adsorption of resin. The total amount of amino acids in 100 g wheat germ protein hydrolysates is 93.95 g. Wheat germ protein hydrolysates are primarily composed of 4 fractions: 17.78% in the relative molecular mass range of 115631512, 17.50% in 1512842, 27.38% in 842372 and 30.65% in 37276, respectively. The antioxidant properties of wheat germ protein hydrolysates were evaluated by using different antioxidant tests in vitro. 1.20 g/L wheat germ protein hydrolysates exhibit 78.75% inhibition of peroxidation in linolei acid system; and 1.6g/L wheat germ protein hydrolysates show 81.11% scavenging effect on the 1,1-diphenyl-2-picrylhrazyl radical. The reducing power of 2.50 g/L wheat germ protein hydrolysates is 0.84. Furthermore, the scavenging activity of 0.60 g/L wheat germ protein hydrolysates against superoxide radical is 75.40%; 0.50 g/L wheat germ protein hydrolysates exhibit 63.35% chelating effect on ferrous ion. These antioxidant activities of wheat germ protein hydrolsates increase with the increase of its concentration. Experimental results suggest that wheat germ protein hydrolysate is a suitable natural antioxidant rich in nutrition and nontoxic.
基金Project(2005CB623703) supported by the National Basic Research Program of China
文摘The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe2O4 when content of CaO is less than 4%(mass fraction), bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 MPa, but that of the samples without CaO is only 60 MPa. Fracture toughness is improved obviously by CaO doping, the samples doped with 2% CaO have the maximum fracture toughness of 2.12 MPa ·m1/2 , which is about two times of that of the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe2O4 composite ceramics.
基金Projects supported by The 2nd Stage of Brain Korea and Korea Research Foundation
文摘The high-temperature oxidation resistance behavior of 7% （mass fraction） Y203-ZrO2 thermal barrier coatings （TBCs） irradiated by high-intensity pulsed ion beam （HIPIB） was investigated under the cyclic oxidation condition of 1 050 ℃ and 1 h. The columnar grains in the TBCs disappear after the HIPIB irradiation at ion current densities of 100-200 A/cm^2 and the irradiated surface becomes smooth and densified after remelting and ablation due to the HIPIB irradiation. The thermally grown oxide （TGO） layer thickness of the irradiated TBCs is smaller than that of the original TBCs. After 15 cycles, the mass gains of the original TBCs and those irradiated by ion current densities of 100 and 200 A/cm^2 due to the oxidation are found to be 0.8-0.9, 0.6-0.7, and 0.3-0.4 mg/cm^2, respectively. The inward diffusion of oxygen through the irradiated TBCs is significantly impeded by the densified top layer formed due to irradiation, which is the main reason for the improved overall oxidation resistance of the irradiated TBCs.
