Effect of purging on quality changes of ice-chilled freshwater prawn, Macrobrachium rosenbergii

Abstract Post-harvest purging of freshwater prawn by partly clearing the animal's stomach and guts has been considered as a quality improvement measure before delivery to the market. Duplicate experiments of 18 hr overnight purging of freshwater prawns were conducted to determine the effect of purging on the animal's muscle pH value, ammonia content, soluble/insoluble collagen ratio, texture profile (peak heightlplateau height ratio) and their overall appearance. Experimental results showed no significant difference (P 5 0.05) between the purged prawns and the control in their muscle pH values, ammonia content, solublelinsoluble collagen ratios, and peak heightlplateau height ratios. However, with both control and purged prawns stored on ice, the decrease in peak heightlplateau height, increase in pH, ammonia content and the solublelinsoluble collagen ratio with icechilling time were highly significant (P 5 0.01). Purging helped to improve the appearance slightly.