Analysis And Evaluation Of The Nutritional Composition Of Farmed Male Pufferfish(Takifugu Obscurus)

The nutritional composition (proximate composition, minerals, amino acids andfatty acids) in meat, testes and livers of farmed Takifugu obscurus from two areas(Jiangsu Zhongyang and Shanghai Nengzheng) were investigated. And ahigh-performance liquid chromatography (HPLC) method using pre-columnderivatization for the determination of taurine in the meat of farmed Takifugu obscuruswas developed.All tissues were reported in this study showed that higher contents of crude proteinin meat (18.44%) and testes (17.15%), lower contents in livers (3.89%). At the sametime, higher contents of crude fat(63.86%) were found in livers, lower crude fat contents（1.82%and1.31%, respectively）were found in testes and meat. Concerning about theminerals, it was found that K was the most abundant macroelement in the meat, testesand livers (1462.39±45.07mg/100g,1534.16±49.76mg/100g,102.10±11.96mg/100g, respectively). Zn was the most abundant microelement in meat (7.06±0.60mg/100g) and testes (11.88±0.96mg/100g), Fe (4.94±0.54mg/100g) was the mostabundant microelement in livers. The contents of Se were abundant in both meat andtestes. Furthermore, the mineral contents in meat and testes were significantly higherthan that in livers (P <0.05). As the differences found here were probably stronglyinfluenced by farmed environments and feed.In addition, the contents of total amino acid (TAA) in meat, testes and livers were80.08±0.75g/100g,63.33±0.10g/100g,5.66g/100g, respectively. The ratios of totalessential AA (TEAA) to TAA in the three tissues were between39.05%and40.60%.The ratios were fit to the good protein resource reference values recommended byFAO/WHO, espcially in the meat. The ratios of total umami amino acids (TUAA) toTAA were ranged from41.76%to46.12%, especially the testes contained the highest ratios. It was dominated by glutamic acid (11.97±0.18g/100g) in the meat. Testes weredominated by arginine (8.63±0.01g/100g). According to amino acid score (AAS), thefirst limiting acid in the meat and testes were tryptophan and (phenylalanine+tyrosine),respecially. It was showed that meat and testes are good protein resources. Thedifferences among the three tissues may relate with texture characteristic and maternalcompensation. According to AA composition contents and nutritional evaluation, it wasshowed that the pufferfish from Shanghai was one of good protein resources comparedwith pufferfish from Jiangsu.In the aspect of fatty acids (FA),22kinds of FA were determined in the threetissues. The total fatty acid content in livers (64.07%) was significantly higher than thatin meat (1.31%) and testes (1.82%). The content of polyunsaturated fatty acids (PUFA)was high in meat(0.52%). The contents of mono-unsaturated fatty acids were high inthe testes (0.76%) and livers (42.07%). The FA contents in the3tissues were dominatedby oleic acid (it was33.53%in livers, especially). The contents of AA(0.08%)in thetestes was higher than some fresh water fishes, since AA contents be concentrated forforming sperm membrane and strengthening sperm quality during breeding phase. Thecontents of DHA(1.96%)、EPA(0.68%)、AA(0.30%)in livers significantly higherthan that in meat and testes. The ratio of DHA/EPA in livers was reached to2.88, mayrelated to intake more nutrients from feeding. Furthermore, the ratios of n-6/n-3in liverswas0.41, it was showed that high content of n-3PUFA existed in the farmed pufferfish.The differences of FA compositon and contents in livers from two areas were explainedthat farmed environment and energy consumption were different.As taurine is abundant in the meat of farmed Takifugu obscurus, the content wasfurther to be determined in this study.Taurine was derivatized with Ophthalaldehyde(OPA). The derivatives were separated on a reversed-phase XbridgeTMC18column by amobile phase using (A) methanol,(B) acetonitrile and (C) water (10/20/70). Samplesize was about20μL, flow rate was about1mL/min and detected at330nm byultraviolet detector. Results showed that the linear ranger of taurine was5～30μg/mL,correlation coefficient(R2)=0.9991.The recoveries=95.35～98.19%，relative standarddeviation(RSD)＝2.03～3.71%(n=3). The precision RSD=0.51%(n=6) and thedetection limit was1.14μg/mL. The taurine contents in the meat from J. and S. were 442.08±5.99mg/100g and396.59±1.96mg/100g, respectively.The research on this topic not only provided basic data for the development ofpufferfish farming and effective utilization of pufferfish resources, but also guiding thefuture development of pufferfish consumption market.