Anisakis simplex allergens remain active after conventional or microwave heating and pepsin treatments of chilled and frozen L3 larvae

Abstract

BACKGROUND: Some Anisakis simplex allergens, Ani s 4 among them, are reported to be resistant to freezing, heat and pepsin. However, the effect of conventional and microwave heating on live and frozen larvae, common conditions for fish preparation, and consecutive pepsin treatment have not been studied previously. In this study, live and frozen/thawed A. simplex larvae were subjected to conventional or microwave heating during time–temperature sufficient to kill live larvae, and digested with pepsin in the strong conditions used in fish inspection. The antigenicity of A. simplex in the larvae extracts and in the incubation media filtrates after all treatments was studied. RESULTS: The immunoblotting assay showed the presence of Ani s 4 in all the larvae extracts and all the incubation media filtrates. A. simplex crude antigens were detected in all conditions; nevertheless, differences were observed among treatments, with lower values detected in the filtrates obtained after the strong acidic pepsin treatment. CONCLUSION: The results indicate that ingestion of A. simplex larvae can cause allergy in consumers already sensitised to this allergen, even if the parasitised fish is consumed well‐cooked and after freezing in the recommended conditions selected for killing the larvae to avoid human anisakiasis. Copyright © 2009 Society of Chemical Industry

Antigenicity of Anisakis simplex s.s. L3 in parasitized fish after heating conditions used in the canning processing

“…However, the heating conditions during the pre‐heating may have led to trapping of some soluble compounds, including the allergens, into the protein matrix in a higher percentage than without a pre‐heating step. In addition, the harsher heating conditions of PC‐L samples, as opposed to DR‐L, could in principle liberate more allergen from the Anisakis , probably owing to the changes in permeability of the cuticle due to the heat conditions applied . Another factor is the denaturation stability of Ani s 4 upon heating.…”

“…High pressure applied to infected muscle or isolated larvae also causes the death of the larvae. The minimum pressure necessary to kill the larvae is ≥200 MPa, although the time of application differs among studies . However, some Anisakis allergens remain stable at conditions of pressure and time higher than 200 MPa for 15 min, and even after pepsin treatment …”

Morphological and molecular diagnosis of Pseudoterranova decipiens (sensu stricto) (Anisakidae) in imported cod sold in Brazil

“…With regard to the harmful effects of these parasites on human health, various authors have produced contradictory results/conclusions about the efficacy of salting to inactivate helminth larvae (RAMOS, 2011). Some authors claim that only live parasites can affect human health (ALONSO et al, 1997;RODRÍGUEZ et al, 2006;AUDICANA & KENNEDY, 2008), while others have demonstrated that even inactivated parasites can cause allergic reactions (FERNÁNDEZ DE CORRES et al, 1996;DEL REY MORENO et al, 2006;VIDACEK et al, 2009).…”

IgE sensitisation to the fish parasite Anisakis simplex in a Norwegian population . A pilot study

“…In addition, Norwegians consume a considerable amount of farmed fish and a recent study has shown that anisakid nematodes seem to be absent from the flesh of farmed Atlantic salmon in Norway [29]. On the other hand, studies have reported several thermo and pepsin-resistant allergens of A. simplex [7,8]. Therefore an option remains that ingestion of dead parasites in fishery products could lead to IgE sensitisation and thus still represents a health hazard to the consumers.…”

“…Moreover, A. simplex larvae may induce IgE-mediated allergic reactions such as urticaria and anaphylaxis in sensitised persons [6]. Some studies have reported several thermo and pepsin-resistant allergens of A. simplex and therefore ingestion of material even from dead parasites in fishery products may represent health hazards to the consumers [7,8]. According to one study, the most common hidden food allergen was found to be the A. simplex larvae present in fish and shellfish [9].…”