The impact of autolysis times prior to salting and salt concentrations on the physicochemical and sensory characteristics of Ka-pi-plaa, Thai fermented fish paste produced from beardless barb

Influences of different autolysis times on the quality of beardless barb (Anematichthys apogon) and the resultant fermented fish paste, known as Ka-pi-plaa, were studied. When beardless barb was left to undergo autolysis at ambient temperature (28–30 °C) for a maximum of 36 h, the pH, thiobarbituric acid reactive substances, total volatile base, trimethylamine contents and total viable counts increased with increasing autolysis time. Analysis of fish proteolytic degradation using SDS-PAGE showed little hydrolysis of myosin heavy chain, but a notable increase in the amount of trichloroacetic acid-soluble peptides was detected over time (P < 0.05). The autolysis time of beardless barb before salting, as well as salt concentration, significantly impacted the quality of resultant Ka-pi-plaa. The Ka-pi-plaa that was made by combining salt and beardless barb stored for 24 h in 7:1 (w/w) ratio received the greatest overall likeness scores. Hence, the autolysis time of fish utilized as the primary ingredient and the quantity of salt should be considered as crucial factors in determining the characteristics as well as quality of final Ka-pi-plaa.