67C-15 |
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D.-F. Hwang1, C.-I. Wei2, T.-Y. CHEN1, and C.-Y. Shiau1. (1) Dept. of Food Science, National Taiwan Ocean Univ., 2 Pei-Ning Rd., Keelung, 202, Taiwan, (2) Dept. of Nutritional Sciences, Oklahoma State Univ., 143 HES, Stillwater, OK 74078 The harmless puffer fish Lagocephalus gloveri has been used to prepare dried dressed fish fillet, a favorite Taiwanese snack food. However, because of morphological similarities, the manufacturers have difficulty in distinguishing L. gloveri from toxic L. lunaris which accumulates tetrodotoxin in its muscle. Therefore, food poisoning incidents due to ingestion of toxic dried dressed fish fillets have occasionally occurred in Taiwan. The development of effective identification methodologies for puffer fish identification is critically needed for consumer protection. The aims of this study were to determine the differential characterization of the urea-soluble protein components of puffer fish species and to establish a preliminary proteomic database. Muscle proteins of five species (Lagocephalus gloveri, L. wheeleri, L. lunaris, L. inermis, and L. sceleratus) were extracted by 8 M urea solution and determined by Coomassie protein assay, followed by immobilized pH gradient-2-D electrophoresis. The gel images were analyzed by the Discovery Series PDQuest 2-D Analysis Software. The puffer fish proteins resolved into 171-260 spots in the 2-D gels, with a pI range of 3-10 and molecular weight (Mw) range of 7.4-205.0 kD. Fish proteins in the pI region of 3.5-7.0 and Mws of 7.4-45.0 kD were well resolved for species comparison. The abundant puffer fish proteins were neutral/acidic in nature and had low Mws. The major protein spot appeared to be tropomyosin (pI 4.6/36.8-37.3 kD) when compared to sea bass proteome. From the 2-D pattern similarity analysis, the match rates of the protein spots for the four species to those of L. gloveri ranged from 20.8% to 29.6%, while that for L. wheeleri and L. inermis was the highest at above 40%. The more acidic proteins of lower Mws showed species-specific characteristics. Therefore, the species of puffer fish can be differentiated from the comparison of the characteristic 2-D protein patterns.
Session 67C, Food Chemistry: Food analysis, irradiation and toxicology
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