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

This work investigated the efficacy of rosemary essential oil (REO) and <i>Boswellia serrata</i> extracts (BSE) against <i>Anisakis</i> larvae for possible industrial applications. <i>In-vitro</i> assays exposed <i>Anisakis</i> type I larvae to various media containing REO (1-5%) or BSE (1-5%) with spermidine and ferulic acid at different temperatures and times. <i>Ex-vivo</i> 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%. <i>Ex-vivo</i> 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 <i>Anisakis</i> risk management.