罗非鱼体内土腥味物质的分布特征研究

Study on distribution characteristics of earthy odor in tilapia

中文关键词:  罗非鱼  土腥素  二甲基异莰醇  固相微萃取  膳食评估

英文关键词:tilapia  geosmin  2-methylisoborneol  solid phase microextraction  dietary evaluation

中文摘要:

      目的 探究罗非鱼体内土腥味物质在不同组织间的分布特征, 为罗非鱼土腥味问题提供膳食建议。方法 采用微波辅助蒸馏-固相微萃取-气相质谱分析法对养殖水体和罗非鱼体内各部位(罗非鱼肠道内容物、血液、肝脏和肌肉组织)的土臭素(geosmin, GSM)和二甲基异莰醇(2-methylisoborneol, 2-MIB)进行检测和比较。结果 检出的土腥味物质为GSM, 2-MIB未检出。鱼肉中GSM浓度均值范围分别为血液0.59~0.80 μg/L、肠道内容物2.27~5.00 μg/kg、肝脏0.97~2.58 μg/kg、肌肉0.64~0.97 μg/kg, 肠道内容物中GSM含量显著高于肝脏、血液和肌肉(P<0.05), 肝脏则显著高于血液和肌肉(P<0.05)。鱼体土腥味贡献率依次为肌肉组织>肠道内容物>肝脏>血液。结论 水体和鱼体中的GSM含量具有明显的相关性(r2=-0.293、r2=0.238、r2=0.488、r2=0.524), 罗非鱼中的土腥味物质在肠道中含量最高, 但是根据贡献率, 罗非鱼的土腥味物质主要集中在肌肉中, 肌肉是罗非鱼土腥味的主要贡献者。

英文摘要:

      Objective To explore the distribution characteristics of earthy odor in different tissues of tilapia, and provide dietary suggestions for earthy odor problems of earthy odor in tilapia. Methods Geosmin (GSM) and 2-methylisobornenol (2-MIB) in various parts (intestinal content, blood, liver and muscle tissues of tilapia) of aquaculture water and tilapia were detected and compared by microwave-assisted distillation-solid phase microextraction-gas mass spectrometry. Results The detected earthy odor substance was GSM, and 2-MIB was not detected. The mean concentrations of GSM in fish ranged from 0.59-0.80 μg/L in blood, 2.27-5.00 μg/kg in intestinal content, 0.97-2.58 μg/kg in liver, and 0.64-0.97 μg/kg in muscle. The content of GSM in intestinal contents was significantly higher than that in liver, blood and muscle (P<0.05), and that in liver was significantly higher than that in blood and muscle (P<0.05). The contribution rate of earthy odor in fish was in the order of muscle tissue>intestinal content>liver>blood. Conclusion There is a significant correlation between fish and GSM content in water (r2=-0.293, r2=0.238, r2=0.488, r2=0.524), and the earthy smell of tilapia is the highest in intestinal tract, but according to the contribution rate, the earthy smell of tilapia is mainly concentrated in muscle, and muscle is the main contributor to the earthy smell of tilapia.