Hplc Phenolic Composition, Bioactivities of Spices and Their Effect on the Sensory Properties of Hot Smoked Fillets of Pangasius Hypophthalmus

Smoked fish, although highly appreciated, is a very perishable product due to its chemical composition, hence the need to add bio-preservatives such as spices which also add value to the finished product. In this preliminary study, the antioxidant capacity, the antimicrobial activity, the phenolic profile and the sensory properties of aqueous extracts of the spices ( Xylopia aethiopica , Aframomum citratum , Aframomum melegueta , Afrostyrax lepidophyllus , Monodora myristica , Syzygium aromaticum , black and white Piper nigrum ) were determined, in order to evaluate their biopreservative potential. The results obtained showed that the aqueous extracts of S. aromaticum , X. aethiopica and black P. nigrum have the strongest antiradical (DPPH and ABTS test) and reducing capacities (FRAP-TPTZ, RP and TAC test). Likewise, these extracts showed inhibitory activity on all bacterial strains tested ( Salmonella enterica , Salmonella newport , Salmonella typhi , Listeria monocytogenes and Staphylococcus aureus ) with minimum inhibitory concentration (MIC) from 1.56 to 12.5 mg/mL. High performance liquid chromatography analysis revealed that gallic acid (0.85 – 5670.77 µg/g DW) and eugenol (0.03 – 5150.15 µg/g DW) were detected in the aqueous extracts of all the spices. On the other hand, smoked fillets of Pangasius hypophthalmus added with the spices A. lepidophyllus , M. myristica and white P. nigrum were the most accepted after sensory evaluation using the hedonic test. This study suggests that certain local spices used in the preparation of “ Mbongo tchobi ” may add value to hot-smoked fish and may extend their shelf life