Effects of Fermentation on Physical Properties and Lactic Acid Bacteria (LAB) Growth in Fermented Fish (Pekasam)d Fish (Pekasam)

Abstract

Fermentation of fish is a food processing method that enables the storage of fish for extended periods. Pekasam is an example of freshwater fermented fish from Malaysia. Fermented fish or seafood causes the presence of lactic acid bacteria (LAB) such as Lactobacillus spp. to aid in the fermentation process. However, the fermentation process can alter the physical properties of the fish, which directly affect consumer acceptability and product quality. Therefore, there is a critical need to evaluate the physical changes occurring in freshwater fermented fish throughout the fermentation period. The goals of this study were to determine the physical properties of different freshwater fish before and after fermentation and to evaluate the colony of LAB during the production of fermented fish. Three species of freshwater fish, silver barbs, three-spot gourami, and climbing perch were prepared and fermented for 7 days. The water activity (aw), salt content, and protein composition were measured using the AOAC method. The LAB growth was measured using the total plate count method (TPC). The aw for all fishes, silver barb, climbing perch, and three-spot gourami significantly decreased after 7 days of fermentation from 0.96% to 0.77% due to the presence of salt in fermented fish. Silver barb recorded the highest salt content (2.70%) after 7 days of fermentation, followed by three-spot gourami (2.10%) and climbing perch (1.60%). The crude protein content for all fish species decreased significantly from a range of 78.07% to 59.82% before fermentation and 57.76% to 37.83% after fermentation due to the protein hydrolysis process. The result of the viability of the LAB growth showed that the three-spot gourami had the highest log CFU/mL, which was 7.46. This corresponds with its highest protein content among the three fish species.