Densities of glycine,L-alanine and L-serine in various aqueous D-xylose solutions were measured at 298.15 K by an Anton Paar Model 55 densimeter.Apparent molar volumes,limiting partial molar volumes and hydration numb...Densities of glycine,L-alanine and L-serine in various aqueous D-xylose solutions were measured at 298.15 K by an Anton Paar Model 55 densimeter.Apparent molar volumes,limiting partial molar volumes and hydration numbers for these amino acids were calculated.The transfer volumes from water to aqueous(D-xylose) solutions were obtained and discussed in terms of the structural hydration interaction model.The results show that all of the transfer volumes are positive,and increase with increasing xylose concentration;the side-chain contributions to the transfer volumes are highly related to the nature of side-chain groups;the hydration numbers for the three amino acids in solutions decrease with increasing xylose concentration.展开更多
为分析实际体系美拉德反应产物(MRPs)的抗氧化活性,采用4种不同品种鱼肉(鲢鱼、草鱼、鲫鱼和鲤鱼)蛋白与D-木糖建立实际体系进行美拉德反应,反应产物通过恒温油浴加热制备,以DPPH自由基(DPPH·)作为美拉德反应产物抗氧化活性的测定...为分析实际体系美拉德反应产物(MRPs)的抗氧化活性,采用4种不同品种鱼肉(鲢鱼、草鱼、鲫鱼和鲤鱼)蛋白与D-木糖建立实际体系进行美拉德反应,反应产物通过恒温油浴加热制备,以DPPH自由基(DPPH·)作为美拉德反应产物抗氧化活性的测定指标。单因素试验考察加热温度、时间、p H及反应底物质量比对美拉德反应的影响,优化出MRPs抗氧化活性最强的鲫鱼蛋白-D-木糖为实际反应体系。均匀试验结果表明,鲫鱼蛋白-D-木糖实际体系MRPs对DPPH自由基的清除率最高,抗氧化活性最强。且最佳工艺条件为:反应时间70 min,温度136℃,初始p H 12.0及反应底物质量比(鲫鱼蛋白∶D-木糖)为3∶1。展开更多
文摘Densities of glycine,L-alanine and L-serine in various aqueous D-xylose solutions were measured at 298.15 K by an Anton Paar Model 55 densimeter.Apparent molar volumes,limiting partial molar volumes and hydration numbers for these amino acids were calculated.The transfer volumes from water to aqueous(D-xylose) solutions were obtained and discussed in terms of the structural hydration interaction model.The results show that all of the transfer volumes are positive,and increase with increasing xylose concentration;the side-chain contributions to the transfer volumes are highly related to the nature of side-chain groups;the hydration numbers for the three amino acids in solutions decrease with increasing xylose concentration.
文摘为分析实际体系美拉德反应产物(MRPs)的抗氧化活性,采用4种不同品种鱼肉(鲢鱼、草鱼、鲫鱼和鲤鱼)蛋白与D-木糖建立实际体系进行美拉德反应,反应产物通过恒温油浴加热制备,以DPPH自由基(DPPH·)作为美拉德反应产物抗氧化活性的测定指标。单因素试验考察加热温度、时间、p H及反应底物质量比对美拉德反应的影响,优化出MRPs抗氧化活性最强的鲫鱼蛋白-D-木糖为实际反应体系。均匀试验结果表明,鲫鱼蛋白-D-木糖实际体系MRPs对DPPH自由基的清除率最高,抗氧化活性最强。且最佳工艺条件为:反应时间70 min,温度136℃,初始p H 12.0及反应底物质量比(鲫鱼蛋白∶D-木糖)为3∶1。