Abstract: The detection of morphology index is an important part of routine nutrition evaluation of fish. At present, the method of analyzing fish tissue-weight ratio will cause damage to fish, and the sampling process is complex, so it is urgent to analyze fish tissue-weight ratio by rapid non-destructive detection technology. Low-field nuclear magnetic resonance (NMR) technology has the characteristics of rapid and nondestructive detection. Low-field NMR T1 spectroscopy has been used to detect the volume of adipose tissue in mice, but low-field NMR T1-T2 spectroscopy has not been used for qualitative and quantitative analysis of fish tissues and organs yet. Based on this, the muscle tissue, abdominal adipose tissue, liver tissue and intestinal tissue of tilapia after separation were scanned and analyzed by using low-field NMR T1-T2 spectroscopy independently and mixed. It was found that the muscle tissue and abdominal adipose tissue of tilapia could be separated by using low-field NMR T1-T2 spectroscopy, but liver tissue and intestinal tissue could not be distinguished. Furthermore, a quantitative analysis model was established for muscle tissue and adipose tissue which could be separated, and the correlation between tissue signal strength and tissue weight of tilapia was analyzed. The results showed that the correlation (R2) of muscle tissue was 0.974 3, and that of abdominal adipose tissue was 0965 0. The reliability of the quantitative analysis model of muscle tissue was verified by tilapia in vivo, and the muscle signal size in vivo was converted into muscle tissue weight and its correlation with the whole fish weight was analyzed. The results showed that the correlation (R2) between muscle tissue weight and body weight was 0.806 9. The research showed that the low-field NMR T1-T2 spectroscopy could be used to quantitatively analyze the content of muscle tissue in fish quickly and non-destructively.

Key words: fish nutrition, low-field nuclear magnetic resonance T1-T2 spectroscopy, tilapia, muscle tissue

摘要： 形体指标的检测是鱼类常规营养评定的重要组成部分。目前，分析鱼类组织体重比的方法会对鱼体造成损伤，且取样过程复杂，迫切需要无损快速检测技术分析鱼体组织占比。低场核磁共振技术具有快速无损检测的特点，已有研究利用低场核磁共振T1谱技术检测小鼠内脂肪组织体积，但尚未有研究应用低场核磁共振T1-T2谱技术对鱼类各组织器官进行定性和定量分析。基于此，利用低场核磁共振T1-T2谱技术，将分离后的罗非鱼的肌肉组织、腹腔脂肪组织、肝脏组织、肠道组织单独以及混合后进行扫描分析，结果发现利用低场核磁共振T1-T2谱技术可以分离罗非鱼肌肉组织和腹腔脂肪组织，但是无法区分肝脏组织和肠道组织。进一步对能够实现分离的肌肉组织和脂肪组织建立定量分析的模型，分析罗非鱼组织信号强度与组织重量相关性，结果显示，肌肉组织相关性R2=0.974 3，腹腔脂肪组织相关性R2=0965 0。并利用罗非鱼活体验证了肌肉组织定量分析模型的可靠性，将活体扫描肌肉信号大小转换成肌肉组织重量并分析其与全鱼体重相关性，结果显示肌肉组织重量与体重相关性R2=0.806 9。研究表明，在鱼类营养代谢研究中，可以利用低场核磁共振T1-T2谱技术快速无损地定量分析鱼体内肌肉组织含量。

关键词: 鱼类营养, 低场核磁共振T1-T2谱, 罗非鱼, 肌肉组织