Microbiological evaluation and storage stability of snakehead fish extract (Channa striata) using steaming method

The snakehead fish (SHF) has commercial value due to its health benefit. Steaming extraction method using distilled water within temperature below 60°C is the one of extraction methods to obtaining the SHF extract with high yield of valuable soluble protein albumin, as well as relatively simple to applied at home industries. Recently, the recommended storage for these conventional steamed SHF extract (SSHFE) product is in freeze temperature (-20°C), not in room temperature. Evaluation to find scientific reason related to the SSHFE storage stability is necessary required. The series of storage stability and microbiological test toward SSHFE had investigated included total plate count (TPC); most probable number (MPN) of coliform and Eschericia coli test using Gram staining and Indol, Methyl Red, Voges Praskauer, Citrate (IMVIC) at different storage stability treatments. This research found that SHF extract during storage of 0 week after out from freezer were negatively contaminated (TPC= <10² CFU/ml). While, TPC at storage of 1; 4; 8 weeks after out from freezer showed contamination in level of 1.722x10³ CFU/ml; 1.327x10⁴. CFU/ml and 6.839x10⁴ CFU/ml, respectively which still below threshold that stipulated by Indonesian Food Standardization (5x10⁵ CFU/ml). While MPN index were exceed the standard, i.e. 24/g (1 week), 350/g (4 weeks), and <1600/g (8 weeks). Moreover, the gram stain and IMVIC test indicated that they were positively contaminated by Eschericia coli. Accordingly, SSHFE is recommended to store at freeze temperature and immediately consumed after melt in room temperature. Further research of sterilizing methods for SSHFE processing is suggested.