Effect of antibacterial agents on quality characteristics of iced headless giant freshwater prawn (Macrobrachium rosenbergii de Man)

Abstract

The experiment was designed to investigate the effect of antibacterial agents including sodium lactate, sodium acetate, and sodium triphosphate at the equal concentration of 10% (w/w) on quality characteristics and shelf-life of headless giant freshwater prawns. The prawns were dipped (2 minutes) in each antibacterial solution and stored in ice. Quality characteristics including psychrotrophic bacteria, mesophilic bacteria, surface color, muscle hardness, muscular pH, total volatile base nitrogen, and sensorial scores (appearance, odor, hand-feel texture, and overall acceptability) were measured on day 0, 4, 8, 12, 16, and 20 after storage. All antibacterial agents had no effect on surface color, muscular pH, muscle hardness, odor, and hand-feel texture of prawn meat. Sodium acetate effectively decreased total volatile base nitrogen. Sodium acetate and sodium triphosphate effectively reduced psychrotrophic bacteria by 1.77 and 1.50 log cfu/g, respectively. In addition, they reduced mesophilic bacteria by 0.93 and 0.65 log cfu/g, respectively, when compared to the control. The reduction of bacteria in the prawns after dipping in sodium acetate and sodium triphosphate delayed the prawn spoilage, which resulted in higher sensorial scores (appearance and overall acceptability) compared to the control. Sodium acetate and sodium triphosphate effectively extended shelf-life of the prawns from 12 to more than 20 days (>60 %).