Effectiveness of salt and propolis combinations in preservation of Brycinus nurse from Lake Albert, Uganda

Abstract

Brycinus nurse from Lake Albert takes long period of time from 3-7 days to dry. This compromises its quality, often resulting in its diversion to animal feed rather than human consumption. The study was designed to hasten drying rate and therefore reduce the percentage of B. nurse being channeled to feed production. This study investigated the effectiveness of salt and honeybee propolis (HBP) combinations in preservation of Brycinus nurse (Ruppell, 1832) from Lake Albert, Uganda. In order to achieve this, B. nurse samples were subjected to sixteen (16) different concentrations of salt, propolis, and salt-propolis combinations and sun-drying. During 150 days of storage at room temperature, samples were evaluated every 30 days for sensory, chemical, and microbial characteristics to determine the overall acceptability. The results indicated that, the most effective salt and HBP concentrations for preserving B. nurse were 20% and 15% respectively. B. nurse samples preserved with HBP were rejected earlier than those of salt, indicating that salt is a stronger preservative than HPB. Effective combination of HBP and salt was 20% Salt + 15% HBP for both sensory, microbial and chemical quality as it exhibited higher sustained acceptability scores than the rest of the samples throughout the storage time. However the study found out that 20% salt + 10% HBP, 20% salt + 15% HBP 30% salt + 5% HBP, 30% salt + 10% HBP, and 30% salt + 15% HBP combinations preserved the fish samples for 150 days. It can be concluded that Salt-HBP combination is more effective in preservation of B. nurse compared to salt and HBP. This study provides the first systematic evaluation of salt–HBP combinations for fish preservation in Uganda, demonstrating their synergistic effect in extending shelf life, and enhancing fish marketability. Introducing propolis, a locally available, underutilized natural preservative, this research advances existing knowledge on sustainable fish preservation technologies and offers practical solutions for reducing post-harvest losses and improving livelihoods among fishing communities around Lake Albert. The study recommends using propolis and salt combinations of 20% salt + 15% HBP due to their synergistic effect in maintaining sensory, microbial, chemical properties and its acceptability, marketability and profitability. Key words: Brycinus nurse, Salt, Honeybee propolis, Alestidae