Natural extracts and bioactive compounds against L3 larvae of Anisakis spp: in vitro and ex vivo evaluation and potential application in marinated products

This work investigated the efficacy of rosemary essential oil (REO) and Boswellia serrata extracts (BSE) against Anisakis larvae for possible industrial applications. In-vitro assays exposed Anisakis type I larvae to various media containing REO (1-5%) or BSE (1-5%) with spermidine and ferulic acid at different temperatures and times. Ex-vivo trials in experimentally infested anchovy fillets were carried out only for REO. REO demonstrated significant anisakicidal activity, achieving the fastest efficacy in oil (15h at 4 °C with 5% REO). Lower concentrations (1%) showed limited effectiveness. BSE achieved a maximum 92% larval devitalisation at 5%. Ex-vivo experiments revealed initial devitalisation after 72h, reaching 100% by 168h in anchovy fillets with 5% REO-oil at 20 °C. REO exhibited substantial anisakicidal effects in marinated anchovies under refrigeration and lipid conditions. These findings highlight REO as a promising natural additive for enhancing marinated fish product safety, offering an alternative or complement to freezing for Anisakis risk management.