Antimicrobial activity of natural compounds against Listeria spp. and their effects on sensory attributes in salmon (Salmo salar) and cod (Gadus morhua).

Publication date: Available online 15 July 2019Source: Food ControlAuthor(s): S. Pedrós-Garrido, I. Clemente, J.B. Calanche, S. Condón-Abanto, J.A. Beltrán, J.G. Lyng, N. Brunton, D. Bolton, P. WhyteAbstractThe application of natural preservatives on fresh fish has potential to extend shelf-life. In the present study, 8 essential oils (EOs) (lemon, lemongrass, lime, garlic, onion, oregano, thyme and rosemary) and 3 organic acids (OAs) (ascorbic, citric and lactic) were evaluated. The antimicrobial activity of these compounds was tested in-vitro against four confirmed Listeria spp. isolated from retail skin-packed salmon and cod. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were established for each compound. Then, a sensory evaluation was performed by a panel of ‘expert assessors’ on cooked fish treated with all of the OAs and any 4 EOs with a MIC <0.8%. A series of descriptors were assigned to characterize the combination of each compound with cooked salmon or cod.The highest antimicrobial effect against all Listeria spp. was observed for lactic acid (0.31-2.5%), but treatment with this compound resulted in the development of organoleptically unacceptable changes in salmon or cod. The most acceptable OAs for salmon and cod were ascorbic acid (1.25%) and citric acid (0.63%) respectively, which were shown to enhance certain organoleptic characteristics.The most effective EO against all Listeria strains evaluated was oregano...
Source: Food Control - Category: Food Science Source Type: research