【作者】 艳茹；

【导师】 德力格尔桑；

【作者基本信息】 内蒙古农业大学 ， 农产品加工及贮藏工程， 2006， 硕士

【摘要】 利用生物电阻抗仪检测了30头肉牛宰后1～10天(1～-1℃)的生物电阻抗值变化,同时测定pH、羟脯氨酸、肌浆Ca2+浓度和游离氨基酸含量。结果表明:随着驱动频率的升高生物电阻抗值均呈下降趋势,宰后初期电阻抗值上升,直到第三天生物电阻抗值达到最大,第四天开始逐渐下降。骨骼肌肉电极化系数随时间呈下降趋势,第三天稍有起伏。介电损耗正切角宰后前三天呈上升趋势,第四天开始下降。随着时间的延长介电损耗正切角变化差异显著(p<0.05)。宰后特征频率随时间延长而增大,变化范围为10～200KHz。宰后前几天阻抗值的位点分布在Cole-Cole圆图的左侧,随着时间的推移向右移动。频率在5KHz～100KHz时,肌纤维方向对牛肉生物电阻抗的影响较大,横向电阻(沿垂直于骨骼肌方向)大于纵向电阻(沿骨骼肌方向),100KHz～200KHz时,肌纤维方向的影响不明显。宰后前三天pH值与生物电阻抗呈现极大负相关,r=-0.99～-1(p<0.01)。生物电阻抗值与羟脯氨酸含量无明显的相关性。生物电阻抗值与Ca2+浓度、总游离氨基酸含量呈负相关(p<0.05)。更多还原

【Abstract】 Changes of bio-impedance and level of hydroxide- praline ,pH,Ca2+ ,total free amino acid of muscle (stored at 1～-1℃) collected from 30 heads of cattle after slaughtering have been studied . The results showed that the higher frequency of initial curent, the lower impedance of the meat sample. Impedances of the sample were increasing at the first 3-day after slaughtering, then lowering steadily after that. Polarization coefficient( K ) changed slightly around third day and the tangent of angle of electric losses(tgδ) were also increasing at the first 3days,and decreasing after then ,the changes were showed significantly(p<0.05).Characteristic frequencies(fc) were increasing during 1～10 days storage time and were ranging from 10 KHz to 200KHz. The track sites of impedance were located mostly in the left side of Cole-Cole plot in early days, then moved to the right side of the plot. Muscle impedance of transverse direction was greater than longitudinal direction.which were remarkble when frequency ranged from 5KHz to 100KHz, but not from 100KHz to 200KHz. Bio-impedances were negatively correlated with pH at first 3 days(p<0.01), were not correlated with the change of hydroxide- praline. The impedance were negatively correlated with the concentration of Ca2+ and free amino acid level of muscle(p<0.05).更多还原