Quality of fish muscle infested with anisakis simplex

7 páginas,2 figura, 5 tablasMarine fish species infested with Anisakidae larvae are reported in many fishing grounds. Besides the problems related to consumerĝ€™s health when the live larvae are ingested (anisakidosis) or to allergic problems caused by the larvae, the products excreted/secreted or released by the larvae are recognized as proteases, protease inhibitors or antioxidants, which can cause changes in fish muscle during storage. To study this problem, live larvae or a homogenate of larvae in water were added in controlled conditions to gelatin agar gels and minced fish muscle and stored at 20 or 5 °C for 7 days. A high activity in the gelatin agar gels was observed, whereas the inclusion of larvae or larvae homogenates in the muscle did not produce detrimental changes in texture, viscosity, color, or oxidation of fish muscle. The electrophoretic pattern of the extracted natural actomyosin presented fewer changes during storage in the larvae and larvae homogenate added lots than in the control lots. Nevertheless in naturally infested fish different parasite-host mechanisms might be involved. Parasitized fish has to be processed with treatments which kill the larvae to avoid consumersĝ€™ anisakidosis. However, as some of the Anisakis allergens are very stable to heat, patients allergic to Anisakis sp. have to be informed before ingesting parasitized fish or fish products. © 2009 SAGE Publications.This work has been financed by the Spanish projects AGL2005-05699-C02-01 ALI, PIE 2004 7 0E 160, and PIE 2004 7 0E 340 CSIC. Dr Sanja Vidacek carried out her work on a grant provided by the Spanish Ministry of Foreign Affairs, Spanish Agency of International Cooperation (MAE-AECI Scholarship).Peer reviewe

Effect of high hydrostatic pressure on mortality and allergenicity of Anisakis simplex L3 and on muscle properties of infested hake

Background: High pressure (HP) ranging from 100 to 350 MPa (1-15 min) was applied to Anisakis simplex larvae and parasitised hake (Merluccius merluccius) muscle. The aim of the study was to kill the larvae to prevent human anisakidosis, to evaluate the effect on A. simplex allergens and to minimally alter fish muscle quality. Results: The larvae were killed at pressures ≥200 MPa and times ≥1 min, producing alterations in the larva body and ruptures in the cuticle when observed by scanning electron microscopy. Nevertheless, Ani s 4 and A. simplex crude antigens were recognised by immunoblotting and immunohistochemistry at all HPs assayed. Small changes in colour and texture were observed in fish muscle under all pressure/time conditions. Major changes were observed visually at 300 MPa, where the muscle appeared as slightly cooked. Apparent viscosity of muscle homogenates decreased significantly at longer times or higher applied pressure. No changes were detected at 200 MPa in the electrophoretic pattern of proteins treated with or without β-mercaptoethanol, suggesting that disulfide bonds were not formed. Conclusion: Application of HP at 200 MPa for up to 5 min would kill A. simplex larvae, avoiding infestation of the consumer and causing small changes in the hake muscle perceived sensorially. However, HP-treated A. simplex-parasitised fish would still be a potential hazard for consumers allergic to the larvae. © 2009 Society of Chemical Industry.This work has been financed by the Spanish project Plan Nacional de I+D+i AGL2005-05699-C02-01/02 ALI, and CSIC projects: PIE 2004 7 0E 160 CSIC and PIE 2004 7 0E 340Peer Reviewe

Antigenicity and viability of anisakis larvae infesting hake heated at different time-temperature conditions

Heat treatments (40 to 94°C, 30 s to 60 mitt) were applied to different batches of Anisakis simplex L3 larvae isolated from hake ovaries and viscera to study the effect of heat on the viability of the larvae measured as mobility, emission of fluorescence under UV light, and changes in color after staining with specific dyes, and on A. simplex antigenic proteins. The aim was to determine the lowest time-temperature conditions needed to kill the larvae to avoid anisakiasis in consumers, and to evaluate whether high temperature modifies the antigenicity of A. simplex extracts. Heating at 60°C for 10 min (recommended by some authors) was considered unsafe, as differences in viability between batches were found, with some larvae presenting spontaneous movements in one batch. At higher temperatures (≥70°C for ≥1 min), no movement of the larvae was observed. Antigenic protein Ani s 4 and A. simp/ex crude antigens were detected in the larvae heated at 94 ± 1 °C for 3 min. This indicates that allergic symptoms could be provoked in previously sensitized consumers, even if the larvae were killed by heat treatment. Copyright ©, International Association for Food Protection.Peer Reviewe

Viability and antigenicity of Anisakis simplex after conventional and microwave heating at fixed temperatures

8 páginas, 2 figuras, 3 tablasInactivation of parasites in food by microwave treatment may vary due to differences in the characteristics of microwave ovens and food properties. Microwave treatment in standard domestic ovens results in hot and cold spots, and the microwaves do not penetrate all areas of the samples depending on the thickness, which makes it difficult to compare microwave with conventional heat treatments. The viability of Anisakis simplex (isolated larvae and infected fish muscle) heated in a microwave oven with precise temperature control was compared with that of larvae heated in a water bath to investigate any additional effect of the microwaves. At a given temperature, less time was required to kill the larvae by microwaves than by heated water. Microwave treatment killed A. simplex larvae faster than did conventional cooking when the microwaves fully penetrated the samples and resulted in fewer changes in the fish muscle. However, the heat-stable allergen Ani s 4 was detected by immunohistochemistry in the fish muscle after both heat treatments, even at 70°C, suggesting that Ani s 4 allergens were released from the larvae into the surrounding tissue and that the tissues retained their allergenicity even after the larvae were killed by both heat treatments. Thus, microwave cooking will not render fish safe for individuals already sensitized to A. simplex heat-resistant allergens.Spanish projects AGL2005-05699-C02-01/02 and AGL2009-12485-C03-01.Peer reviewe

Does the intensity of anisakis infection affect the quality of hake muscle

The distribution of Anisakis larvae in fresh caught hake was studied, and the influence of three infection levels of the viscera (low, medium, high) on quality changes of deep frozen muscle was followed over 220 days. Differences in quality were attributed more to the size of the individuals than to the infection degree of the three groups. The removal of belly flaps diminished the risk of consumers infection and sensitization as prevalence and intensity was reduced to 75.6 and 5.9%, respectively. Allergens were detected after 220 days frozen storage, which represents a risk for consumers already allergic to Anisakis. © Taylor & Francis Group, LLC.This work was partly financed by the Spanish projects AGL2005-05699-C02-01/02 and AGL2009-12485-C03-01/03Peer Reviewe

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

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 suffi{dotless}cient to kill live larvae, and digested with pepsin in the strong conditions used in fi{dotless}sh inspection. The antigenicity of A. simplex in the larvae extracts and in the incubation media fi{dotless}ltrates after all treatmentswas 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 antigenswere detected in all conditions; nevertheless, differenceswere 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. © 2009 Society of Chemical Industry.This work was financed by the Spanish projects AGL2005-05699-C02-01/02 ALI; PIE 2004 7 0E 160 and PIE 2004 7 0E 340 CSIC. DrSanja Vidaˇcek carried out her work on a grant provided by theSpanish Ministry of ForeignAffairs, Spanish Agency of InternationalCooperation (MAE-AECI Scholarship).Peer Reviewe

Effect of processing technologies on the allergenicity of food products

Heat treatment has been used since ancient times for food processing, firstly to ensure the safety of food and its storage, but also to transform its characteristics (in its raw form) and obtain new textures, flavors, or novel foods. However, the transformation experienced by food components when heated, or processed, can dramatically affect the allergenicity of food, either reducing, or increasing it. To date, most of the articles published dealing with the changes in the potential allergenicity of food are focused on heat treatment and the Maillard reaction. However, it is also important to give prominence to other group of new technologies developed nowadays, such as high-pressure processing, microwaves and food irradiation. These techniques are not likely to replace traditional processing methods, but they are becoming attractive for the food industry due to different reasons, and it is expected in the near future to have different products on the market processed with these new technologies at an affordable cost. Moreover, other biochemical modifications, particularly enzymatic cross-linking of proteins, have attracted wide-spread attention and will be considered as well in this review, because of its great opportunities to induce protein modification and thus affect food allergenicity. Together with the effect of processing of food allergens, this review will place special attention on gastroduodenal digestion of processed allergens, which directly affects their allergenicity.This work was supported by projects COST-Infogest FA 1005, AGL2011-24740 and CYTEDIBEROFUN 110AC0386. S. Benedé acknowledges the financial support of CSIC through her JAE CSIC PhD grant.Peer reviewe