洞庭湖鲶鱼体表黏液和肌肉营养组成对比分析

Comparison of Nutritional Components in Surface Mucus and Muscle of Catfish Grown in Dongting Lake Area

对洞庭湖野生鲶鱼体表黏液及肌肉的营养成分进行分析比较。结果表明:黏液中水分含量极显著高于肌肉(P<0.01),而粗蛋白、粗灰分和粗脂肪含量均极显著低于肌肉(P<0.01)。微量元素含量除Mn外均是黏液显著高于肌肉,Cu、Zn、Fe的比值合理。黏液和肌肉的氨基酸组成基本一致,均含有18种氨基酸,氨基酸总量分别是80.46%和81.65%,呈味氨基酸分别为31.37%和31.35%,必需氨基酸指数(EAAI)分别为59.73、64.53。色氨酸、蛋氨酸和胱氨酸为限制性氨基酸。黏液中二十碳五烯酸(EPA)与二十二碳六烯酸(DHA)的含量极显著高于肌肉(P<0.01),分别为8.79%、13.48%;黏液中花生四烯酸(ARA)的含量为3.21%,而肌肉中未检出。

This study deals with comparisons of nutritional components in surface mucus and muscle of catfish（Silnrus asotus） from Dongting Lake area.Results showed that water content,crude protein,crude fat and crude ash were（95.34 ± 2.38） %,（2.54 ± 0.22） %,（0.52 ± 0.08） % and（1.55 ± 0.17） % in surface mucus;（77.68 ± 3.14） %,（13.81± 0.43） %,（3.79 ± 0.11） % and（4.54 ± 0.15） % in muscle of catfish,respectively.The water content in surface mucus of catfish was significantly higher than that of muscle（P〈0.01）,while crude protein,crude fat and crude ash in muscle were significantly higher than those of surface mucus（P〈0.01）.In dry samples,minerals such as Ca,Zn,Fe and Cu in surface mucus were much higher than those in muscle.The ratios of Zn and Cu,Zn and Fe were rational.Surface mucus of catfish contained 18 kinds of amino acids;so did muscle.The contents of total amino acids（WTAA）,total essential amino acids（WEAA）,total half-essential amino acids（WHEAA）,total nonessential amino acids（WNEAA） in dry samples were（80.46 ± 0.89） %,（25.62 ± 0.69） %,（4.94 ± 0.19） % and（49.91 ± 0.38） % in surface mucus;（81.65 ± 0.80） %,（32.74 ± 0.29） %,（7.35 ± 0.07） % and（41.57 ± 0.55） % in muscle of catfish,respectively.The content of WEAA,WHEAA and WNEAA was significantly difference between surface mucus and muscle（P 〈0.05）.The essential amino acids index（EAAI） was 59.43 and 64.53,respectively.According to nutrition evaluation,amino acid score（AAS） and chemical score（CS）,limited amino acids in surface mucus and muscle were Trp,Met and Cys.There were 6 saturated fatty acids（SFA）,5 mono-unsaturated fatty acids（MUFA） and 5 poly-unsaturated fatty acids（PUFA） in surface mucus of catfish,while 6 SFA,2 MUFA and 4 PUFA in muscle of catfish were observed.The SFA,MUFA and PUFA in fatty aids were（30.98 ± 1.91） %,（28.76 ± 0.68） % and（30.93 ± 0.73） % in surface mucus;（35.03 ±1.31） %,（21.64 ± 0.83） % and（21.41 ± 0.85） %,respectively.The amount of EPA ＋ DHA in fatty acids was（22.27 ± 0.28） % and（7.40 ± 0.22） %,respectively.The amount of MUFA,EPA,DHA,OUFA and EPA ＋ DHA in surface mucus of catfish was significantly higher than muscle（P〈 0.01）.The amount of SFA in surface mucus was significantly lower than muscle（P〈0.05）.The ARA in fatty aids of surface mucus was（3.21 ± 0.38） %,but not detected in muscle.