Title: Differences in sensory characteristics, chemical composition and physical properties of farmed and wild-caught Tilapia and their effect on shelf life.

Nile tilapia (Oreochromis niloticus) is an economically important freshwater fish species in Uganda. The intensive farming of Nile tilapia and the decline in wild-caught tilapia have made farmed tilapia more available to consumers and mainstream seafood markets. This study aimed to evaluate the sensory characteristics, shelf life, and chemical composition of farmed tilapia compared with wild-caught tilapia, and to assess whether existing Quality Index Method (QIM) schemes available in the literature for tilapia, developed primarily for wild-caught fish, can also be applied to farmed tilapia. There was a significant difference (P=0.01) in fat content, with 2.36±0.44 g/100 g of muscle for farmed tilapia and 1.14±0.42 g/100 g of muscle for wild caught tilapia. The difference in water content was significant between farmed and wild-caught tilapia (p<0.05). The water content of farmed tilapia was 77.65±0.43%, and that of wild-caught tilapia was 79.47 ± 1.02 %. Higher Quality Index (QI) scores were recorded for wild-caught tilapia than for farmed tilapia throughout the storage period. A high correlation of R² =0.829 between QI and storage time for wild and R² =0.726 for farmed was recorded. On GDA, positive odour and flavour attributes were higher in farmed than in wild-caught fish. Negative odour and flavour attributes were more prominent in wild-caught than in farmed tilapia. The QI scores increased differently with storage time but showed a linear relationship in both groups. This indicates that the revised QIM scheme is applicable to both farmed and wild-caught tilapia.