Bactericidal effects of organic acids as sanitizing agent on iced storage shrimp

Abstract

The microbial population and sensory of Penaeus vannamei white shrimp were observed during iced storage period in order to keep fresh and prolong its shelf life through treatments by levulinic acid plus sodium dodecyl sulfate (SDS) and lactic acid. Results indicated that the microbial growths in shrimp meat and shrimp intestine were relatively slow. However, the microbial growths in shrimp shell and shrimp head were rapid during iced storage, especially after the 8th day. At the same time, shrimp’s qualities begun to deteriorate on the surface, from shrimp shell and head to the interior of shrimp meat. Treatments by levulinic acid plus SDS and lactic acid were compared. Results demonstrated that both levulinic acid plus SDS and lactic acid effectively reduced the microbial growth in the shrimp meat, head, and shell (p<0.01). The log reduction is related with sanitization concentration, i. e., there were 0.87, 1.06, 0.73, 0.91 log (CFU/g-1) reductions of shrimp shell and head in treatments of dipping 0.5% levulinic acid plus 0.05% SDS, 1.0% levulinic acid plus 0.1% SDS, 0.5% and 1.0% lactic acid when compared with the control group, respectively. Results revealed that levulinic acid plus SDS and lactic acid can be used as sanitizing agents and their antibacterial effects in the shrimp head and shell were better than that obtained from the shrimp meat (p<0.05). The shrimp treated with levulinic acid and SDS had better color, flavor and texture conditions than the control.