Melanosis and quality changes of Pacific white shrimps(Litopenaeus vannamei) treated with Houttuynia cordataextract during cold storage

Changes in melanosis, microbiology, and fat oxidation in Pacific white shrimps (Litopenaeus vannamei) when treated with Houttuynia cordata extract (designated E-DC) were monitored during cold storage for seven days at 20C. Whole shrimps treated with E-DC solution (0.025%, w/v) revealed slow growth of total aerobic microorganisms, Enterobacteriaceae and Pseudomonas aeruginosa, throughout cold storage in comparison to the control sample treated by water (p<0.05). The changes in pH, grey value, and TBARS value (thiobarbituric acid reactive substances) of shrimp samples treated with 0.025% E-DC solution were lower than those of control samples (p<0.05) and not different significantly in comparison to the 1.25% (w/v) sodium metabisulfite (SMS) samples (p>0.05). These results suggested the potential of using natural compounds from vegetable extraction as a safe and effective alternative for commercial chemical-derived preservatives in shrimp storage.