Microbiological, physicochemical, and sensory changes during masin—shrimp fermentation

Masin , a traditional fermented shrimp product originating from Sumbawa, Indonesia, has been studied to understand the transformations it undergoes during fermentation. This research aimed to examine the changes in microbiological, physicochemical, and sensory characteristics of masin throughout the fermentation process. The study utilized rebon shrimp (Acetes indicus), which were combined with salt, granulated sugar, ground red chili, and tamarind in specific proportions (15 salt, 8 sugar, 50 chili, and 5 tamarind). The mixture was sealed in plastic bottles and left to ferment at room temperature for 18 days. Samples were collected every two days to analyze microbiological (lactic acid bacteria and total bacteria), physicochemical (pH, titratable acidity, total volatile base levels, soluble nitrogen, protease activity, water content, color and viscosity), and sensory attributes. The fermentation process of masin involves lactic acid bacteria, whose population peaked during the early stages before declining later. The pH level dropped from 7.13 to 5.02, indicating increased acidity. Total volatile base nitrogen (TVBN) rose significantly, from 26 mg N/100 g to 155 mg N/100 g, by the end of the fermentation period. Sensory changes included the development of a distinct sour aroma, a color shift from red to dark red, and a reduction in viscosity due to shrimp disintegration. Fermentation of masin was considered complete after day 12, characterized by stable pH and TVBN values. The typical sensory characteristics of masin began to appear on day 8, although the pH and TVBN values continued to fluctuate until day 12. © 2025 Elsevier B.V.