The variations of muscle tissus, peroxidase and Ca2+-ATPase activities and Vp （pasteurization value） were investigated with the fresh samples of grass carp （Ctenopharyngodon idellus） heated at different temperatur...The variations of muscle tissus, peroxidase and Ca2+-ATPase activities and Vp （pasteurization value） were investigated with the fresh samples of grass carp （Ctenopharyngodon idellus） heated at different temperatures, thus revealing the mechanism of denaturation of muscle protein by heating. The experimental results showed the great difference in muscle tissue structure before and after the samples heated. In the initial stage of heating the water loss accounted for 50% of the total. When the samples were separately heated at 75, 85, and 95℃, fh values （dehydration curve slope） were 5, 4.1 and 1.7, respectively, while Vp reaching 40 minutes were 22, 8 and 5 min, respectively. As to the time for deactivation of peroxidase in the heated samples at the various temperatures, it varied from 38, 10 and to less than 6 min, respectively and the deactivation rates of Ca2+-ATPase in 1 min were 50%, 88% and 100%, respectively. Consequently, the higher temperature the sample was heated, the faster rate of thermocon ductivity, the lower rate of water loss, and the faster rate of peroxidase deactivation it was. Also, the Vp for the least requirement of pasteurization （Vp≥40min） was obtained.展开更多
为了探讨坛紫菜（Porphyra haitanensisChang et Zheng）干品的等温吸湿曲线特性,为今后的坛紫菜加工和贮藏制定合理的工艺条件,对坛紫菜在5-50℃温度范围内的几条等温吸湿曲线进行了绘制研究,并通过计算机拟合出各曲线相应的回归方程....为了探讨坛紫菜（Porphyra haitanensisChang et Zheng）干品的等温吸湿曲线特性,为今后的坛紫菜加工和贮藏制定合理的工艺条件,对坛紫菜在5-50℃温度范围内的几条等温吸湿曲线进行了绘制研究,并通过计算机拟合出各曲线相应的回归方程.研究结果表明：坛紫菜试样5℃的等温吸湿曲线呈“反S型”,随着温度的升高坛紫菜的等温吸湿曲线从反S型逐渐趋近于类似指数函数曲线;在5-50℃范围内,随着温度的升高,质量干基含水量≤15%的试样水分活度Aw值变化不显著;坛紫菜等温吸湿曲线拟合方程的R^2值均大于0.98.展开更多
文摘The variations of muscle tissus, peroxidase and Ca2+-ATPase activities and Vp （pasteurization value） were investigated with the fresh samples of grass carp （Ctenopharyngodon idellus） heated at different temperatures, thus revealing the mechanism of denaturation of muscle protein by heating. The experimental results showed the great difference in muscle tissue structure before and after the samples heated. In the initial stage of heating the water loss accounted for 50% of the total. When the samples were separately heated at 75, 85, and 95℃, fh values （dehydration curve slope） were 5, 4.1 and 1.7, respectively, while Vp reaching 40 minutes were 22, 8 and 5 min, respectively. As to the time for deactivation of peroxidase in the heated samples at the various temperatures, it varied from 38, 10 and to less than 6 min, respectively and the deactivation rates of Ca2+-ATPase in 1 min were 50%, 88% and 100%, respectively. Consequently, the higher temperature the sample was heated, the faster rate of thermocon ductivity, the lower rate of water loss, and the faster rate of peroxidase deactivation it was. Also, the Vp for the least requirement of pasteurization （Vp≥40min） was obtained.
文摘为了探讨坛紫菜（Porphyra haitanensisChang et Zheng）干品的等温吸湿曲线特性,为今后的坛紫菜加工和贮藏制定合理的工艺条件,对坛紫菜在5-50℃温度范围内的几条等温吸湿曲线进行了绘制研究,并通过计算机拟合出各曲线相应的回归方程.研究结果表明：坛紫菜试样5℃的等温吸湿曲线呈“反S型”,随着温度的升高坛紫菜的等温吸湿曲线从反S型逐渐趋近于类似指数函数曲线;在5-50℃范围内,随着温度的升高,质量干基含水量≤15%的试样水分活度Aw值变化不显著;坛紫菜等温吸湿曲线拟合方程的R^2值均大于0.98.
