Effect of Salt Concentrations on the Proximate Composition, Microbial Load, and Sensory Attributes of Dry-Salted Labeobarbus Species

Abstract

Salting is a traditional fish preservation method that reduces moisture content, enhances shelf life, and improves sensory attributes. In Lake Tana, inconsistent salt application by fishers affects preservation effectiveness, highlighting the need to determine optimal salt concentrations for improved fish quality. The objective of this study was to assess how varying salt concentrations influence the proximate composition, microbial counts, and sensory characteristics of Labeobarbus spp. Mature Labeobarbus spp. of similar length were purchased from the Bahir Dar landing site, then gutted, split into butterfly fillets, and washed. The fish were divided into three equal-weight batches (~3 kg) and dry-salted with coarsely ground commercial-grade NaCl at concentrations of 10%, 20%, and 30% for 7 days. Then the dry-salted products were analyzed for proximate composition, microbial load, and sensory attributes. The study found that higher salt concentrations in dry-salted Labeobarbus spp. reduced moisture content (58.63% at 10% salt treatment to 45.42% at 30% salt treatment) with no significant difference between 20% and 30% salt treatments. The ash content increased, while fat and protein levels did not significantly differ between 20% and 30% treatments. Water activity decreased as salt concentration increased, likely enhancing preservation. Higher salt concentrations also reduced microbial load, with the 30% treatment showing the lowest bacterial load (3.06 log CFU/g). Sensory analysis indicated that the 10% salt treatment scored lower in most attributes, except color, compared to the 20% and 30% treatments, with scores ranging from 2.4 for odor at 10% to 7.6 for color at 20% and 30%. The experimental findings indicate that treatments with 20% and 30% salt concentrations result in desirable sensory attributes and acceptable microbial and nutritional quality.