Activity of R(+) limonene on the maximum growth rate of fish spoilage organisms and related effects on shelf-life prolongation of fresh gilthead sea bream fillets

Anisakicidal Effects of R (+) Limonene: An Alternative to Freezing Treatment in the Industrial Anchovy Marinating Process

Anisakiasis is a fish-borne zoonotic disease caused by the ingestion of raw/undercooked fishes or cephalopods parasitized by members of the genus Anisakis. Freezing ensures the inactivation of viable Anisakis larvae; however, since it affects the organoleptic properties of food, essential oils and their compounds were proposed as an alternative. In this study, fresh anchovy fillets were experimentally parasitized with L3 Anisakis larvae to test the anisakicidal efficacy of R (+) limonene (LMN) in marinated fishery products. The anisakicidal effectiveness and organoleptic influence of several LMN concentrations (0.5%, 1%, and 5%) were tested during the marinating process (MS) and storage in sunflower seed oil (SO) of marinated anchovy fillets. Double treatment (DT) with 1% LMN was also performed both during marination and subsequent storage in oil. MS treatment resulted only in a reduction in larvae viability after 48 h, while a complete inactivation was observed in SO after 8, 10, and 20 days of treatment with 5%, 1%, and 0.5% LMN, respectively. DT was the most effective with complete larval inactivation after 7 days. Only 5% LMN influenced the sensory characteristics of the fillets, resulting, however, in a pleasant lemon-like odor and taste. Considering the results obtained, LMN might be a suitable natural alternative to manage Anisakis risk in the fishery industry.

Analysis of Alternative Shelf Life-Extending Protocols and Their Effect on the Preservation of Seafood Products

Seafood is essential to a healthy and varied diet due to its highly nutritious characteristics. However, seafood products are highly perishable, which results in financial losses and quality concerns for consumers and the industry. Due to changes in consumer concerns, demand for healthy products has increased. New trends focusing on reducing synthetic preservatives require innovation and the application of additional or alternative strategies to extend the shelf life of this type of product. Currently, refrigeration and freezing storage are the most common methods for fish preservation. However, refrigeration alone cannot provide long shelf-life periods for fish, and freezing worsens sensorial characteristics and consumer interest. Therefore, the need to preserve seafood for long periods without exposing it to freezing temperatures exists. This review focuses on the application of other approaches to seafood products, such as biodegradable films and coating technology; superchilling; irradiation; high-pressure processing; hyperbaric storage; and biopreservation with lactic acid bacteria, bacteriocins, or bacteriophages. The efficiency of these techniques is discussed based on their impact on microbiological quality, sensorial degradation, and overall preservation of the product’s nutritional properties. Although these techniques are already known, their use in the industrial processing of seafood is not widespread. Thus, the novelty of this review is the aggregation of recent studies on shelf life extension approaches, which provide useful information for the selection of the most appropriate technology and procedures and industrial innovation. Despite the fact that all techniques inhibit or delay bacterial proliferation and product decay, an undesirable sensory impact may occur depending on the treatment conditions. Although no technique appears to replace refrigeration, the implementation of additional treatments in the seafood processing operation could reduce the need for freezing, extending the shelf life of fresh unfrozen products.

Inhibition of Several Bacterial Species Isolated from Squid and Shrimp Skewers by Different Natural Edible Compounds

Seafood is an excellent source of nutrients, essential for a healthy diet, ranging from proteins and fatty acids to vitamins and minerals. Seafood products are highly perishable foods due to their nutritional characteristics and composition. The application of nontoxic, natural, and edible preservatives to extend the shelf-life and inhibit bacterial proliferation of several foods has been a hot topic. Consequently, this work aimed to perform the microbiological characterization of squid and shrimp skewers during their shelf-life (five days) and evaluate the susceptibility of randomly isolated microorganisms to several natural edible compounds so that their application for the preservation and shelf-life extension of the product might be analyzed in the future. The product had considerably high total microorganisms loads of about 5 log CFU/g at day zero and 9 log CFU/g at day five. In addition, high bacterial counts of Pseudomonas spp., Enterobacterales, and lactic acid bacteria (LAB) were found, especially on the last day of storage, being Pseudomonas the dominant genus. However, no Escherichia coli or Listeria monocytogenes were detected on the analyzed samples. One hundred bacterial isolates were randomly selected and identified through 16s rRNA sequencing, resulting in the detection of several Enterobacterales, Pseudomonas spp., and LAB. The antibacterial activity of carvacrol, olive leaf extract, limonene, Citrox®, different chitosans, and ethanolic propolis extracts was evaluated by the agar diffusion method, and the minimum inhibitory concentration was determined only for Citrox® since only this solution could inhibit all the identified isolates. At concentrations higher than or equal to 1.69% (v/v), Citrox® demonstrated bacteriostatic and bactericidal activity to 97% and 3% of the isolates, respectively. To our knowledge, there are no available data about the effectiveness of this commercial product on seafood isolates. Although preliminary, this study showed evidence that Citrox® has the potential to be used as a natural preservative in these seafood products, improving food safety and quality while reducing waste. However, further studies are required, such as developing a Citrox®-based coating and its application on this matrix to validate its antimicrobial effect.

Influence of Essential Oils on the Microbiological Quality of Fish Meat during Storage

Simple Summary

Fish meat is highly perishable due to its composition and the naturally present microbiota. The food industry aims to provide healthy, safe, and high-quality products to the market. Several strategies, including the use of natural preservatives, may be used to enhance food shelf life, and they can also be combined with others, such as vacuum packaging. This being the case, essential oils are natural plant components that, due to their composition, possess high antimicrobial and antioxidant effects, and are therefore good candidates to be tested as fish preservatives together with vacuum packaging. In the present study, essential oils from Citrus lemon and Cinnamomum camphora were added to rainbow trout meat for evaluating the microbiological quality (counts of bacteria and identification of present microbiota) of the fish when vacuum packed and stored for 7 days at 4 °C. Our results show that lemon (0.5% and 1%) as well as C. camphora essential oils (0.5% and 1%) had a positive effect on the microbiological quality of fish meat, keeping a high microbial quality of the fish fillets during 7 days of cold storage. The use of these essential oils in combination with vacuum packaging is beneficial in extending the shelf life of rainbow trout meat. All isolated species under the tested conditions are identified in the present study; such information will be useful for the future development of preservation methodologies that target isolated microorganisms, which will enable the food industry to enhance the shelf life and safety of fish.

Abstract

The aim of the present study was to evaluate the microbiological quality of rainbow trout meat treated with essential oils (EOs from Citrus limon and Cinnamomum camphora) at concentrations of 0.5% and 1.0% in combination with vacuum packaging during storage. The composition of the EOs were analyzed by gas chromatography coupled with mass spectrometry, and total viable counts (TVCs), coliform bacteria (CB), and lactic acid bacteria (LAB) were determined on the zeroth, first, third, fifth, and seventh days of storage at 4 °C. Individual species of isolated microorganisms were identified using a MALDI-TOF MS Biotyper. The results show that the major components of the EOs were linalool (98.1%) in C. camphora and α-limonene in C. limon. The highest number of TVCs and CB were 4.49 log CFU/g and 2.65 log CFU/g in aerobically packed samples at the seventh day. The lowest TVCs were those of samples treated with 1% C. camphora EO. For CB the most effective treatment was 1% lemon EO. LAB were only detected in a few samples, and were never present in aerobically packed samples; the highest number of LAB was 1.39 log CFU/g in samples treated with 1% lemon EO at day seven. The most commonly isolated coliform bacteria were Hafnia alvei, Serratia fonticola, Serratia proteamaculans, Pantoea agglomerans, and Yersinia ruckeri. Lactobacillus sakei, Staphylococcus hominis, and Carnobacterium maltaromaticum were the most frequently isolated bacteria from lactic acid bacteria. In conclusion, C. camphora EO at a concentration of 1% showed the highest antimicrobial activity.

Marinated Anchovies (Engraulis encrasicolus) Prepared with Flavored Olive Oils (Chétoui cv.): Anisakicidal Effect, Microbiological, and Sensory Evaluation

To meet the food demand of future generations, more sustainable food production is needed. Flavored olive oils (FOOs) have been proposed as natural additives to ensure food safety and quality through a more sustainable approach. The chemical composition and antioxidant potential of two different olive oils flavored, respectively, with cumin (Cm) and with a mixture of parsley, garlic, and lemon (Mix) were investigated. Cm-FOO and Mix-FOO were tested against Anisakis both in vitro and ex vivo through an exposure test of anchovy fillets experimentally parasitized with Anisakis larvae. Microbiological and sensory analysis were carried out on marinated anchovy fillets exposed to both FOOs to evaluate their effects on the shelf life and their sensory influence. The addition of herbs and spices did not affect the chemical composition of the olive oil (free acidity, UV absorbance, and fatty acid composition). Only Mix showed antioxidant activity, while Cm had no effect in this regard. Cm-FOO and Mix-FOO devitalized the Anisakis larvae both in vitro within 24 h and ex vivo after 8 and 10 days of exposure, respectively. The results of microbiological analyses showed that FOOs inhibited the growth of typical spoilage flora in the marinated anchovies without negatively affecting their sensory characteristics, as observed from the sensory analysis.

Synergistic Antimicrobial Effectiveness of Plant Essential Oil and Its Application in Seafood Preservation: A Review

The synergistic potential of plant essential oils (EOs) with other conventional and non-conventional antimicrobial agents is a promising strategy for increasing antimicrobial efficacy and controlling foodborne pathogens. Spoilage microorganisms are one of main concerns of seafood products, while the prevention of seafood spoilage principally requires exclusion or inactivation of microbial activity. This review provides a comprehensive overview of recent studies on the synergistic antimicrobial effect of EOs combined with other available chemicals (such as antibiotics, organic acids, and plant extracts) or physical methods (such as high hydrostatic pressure, irradiation, and vacuum-packaging) utilized to reduce the growth of foodborne pathogens and/or to extend the shelf-life of seafood products. This review highlights the synergistic ability of EOs when used as a seafood preservative, discovering the possible routes of the combined techniques for the development of a novel seafood preservation strategy.

Chemical composition, antioxidant capacity and antibacterial action of five Moroccan essential oils against Listeria monocytogenes and different serotypes of Salmonella enterica

Essential oils (EOs) obtained from aromatic plants are rich in natural components with interesting antimicrobial effects. The aim of this study was to evaluate the chemical composition of EOs extracted from Origanum majorana (OM-EO), Mentha suaveolens (MS-EO), Rosmarinus officinalis (RO-EO), Salvia officinalis (SO-EO) and Mentha pulegium (MP-EO). Their antioxidant properties and antibacterial activity against Listeria monocytogenes and different serotypes of Salmonella enterica subsp. enterica were also studied. The EOs were extracted from plants by hydro-distillation and their chemical composition was determined by GC-MS. Terpinen-4-ol, 1,8-Cineole, Camphor, Limonene and Cinerone were the main chemical components found in OM-EO, RO-EO, SO-EO, MP-EO and MS-EO, respectively. To the best of our knowledge, Limonene and Cinerone were reported, for the first time, as the major components of MP-EO and MS-EO. Moreover, our results showed that MS-EO had the best antioxidant activity with an IC₅₀ of 0.78 ± 0.05 mg/mL, EC₅₀ of 1.53 ± 0.07 mg/mL, and RC₅₀ of 0.98 ± 0.04 mg/mL, and the higher antibacterial activity using microdilution broth method with MIC of 0.5% for Salmonella and 0.25% for L. monocytogenes, while OM-EO had the best antibacterial activity using disc diffusion method (inhibition diameters ranged between 15.3 ± 0.3 mm and 18.5 ± 0.3 mm for Salmonella and between 20.1 ± 0.2 mm and 25.4 ± 0.4 mm for L. monocytogenes). However, OM-EO and MS-EO present the higher percentage of sub-lethally injured cells against S. enterica (5.50 ± 0.11%) and L. monocytogenes (5.23 ± 0.07%), respectively. From this study, we can conclude that the investigated EOs are rich in components with interesting antibacterial activity and they could be applied in food preparations as natural preservatives to extend the shelf life of food products and to inhibit the growth of food-borne pathogens.

Targeting fish spoilers Pseudomonas and Shewanella with oregano and nettle extracts

To control Pseudomonas and Shewanella as important psychrotrophic spoilage bacteria in fish meat, we used ethanolic extracts of oregano (Origanum vulgare subsp. vulgare) and nettle (Urtica dioica), with phytochemical characterisation of the extracts and their bioactive compounds. Liquid chromatography coupled with photodiode array detection and electrospray ionisation-mass spectrometry was used for qualitative compositional determination of the extracts. Four main compounds were identified in the oregano extract, with rosmarinic acid the most abundant, followed by three glycosylated phenolics, one of which is reported for the first time in O. vulgare: 4'-O-β-d-glucopyranosyl-3',4'-dihydroxybenzyl-4-hydroxybenzoate. Six main compounds were identified in the nettle extract, as caffeoylmalic acid and five flavonoid glycosides. These oregano and nettle ethanolic extracts showed in-vitro antimicrobial activities against selected Pseudomonas and Shewanella strains in broth and fish meat homogenate when evaluated at two inoculum concentrations. The antimicrobial activities were more pronounced for the nettle extract at the lower inoculum concentration, and for both the Shewanella strains. Growth inhibition in the fish meat homogenate was evaluated at 3.13 mg/mL and 1.56 mg/mL at 5 °C. Again, the nettle extract showed greater antimicrobial activity, which was seen as the lowest maximum growth rate, followed by the oregano extract, which was inhibitory only at 3.13 mg/mL. Finally, the extracts were applied to fish meat that was then stored at 5 °C for 9 days. Evaluation here was for the counts of the mesophilic, psychrotrophic, Pseudomonas and H2S producers. These confirmed the better antimicrobial effects of the nettle extract, especially against the H2S-producing bacteria, which included Shewanella. Both of the extracts were rich in glycosides of flavonoids and phenolic acids. The enzymatic activities of the Pseudomonas and Shewanella spoilage bacteria and their actions on the phenolic glycosides from natural sources will be further investigated.

A new advanced packaging system for extending the shelf life of refrigerated farmed fish fillets

BACKGROUND

An innovative pilot-plant packaging was developed and evaluated for applying oregano essential oil (OEO) vapours in conditions of high vacuum for exploring the antimicrobial effect of essential oil vapours applied immediately before packaging of fish fillets. Farmed sea bream (Sparus aurata) fresh fillets have been used as a model for validating this new technology. These fillets, as a refrigerated product under modified atmosphere packaging (MAP), have a relatively short shelf life (12-14 days) mainly due to the fast microbial growth. The effects of conventional OEO dippings [pretreatment dipping (0.1% of OEO) of whole fish (T1) and filleted sea bream (T2)] were compared with the OEO application in vapour phase (67 μL L^-1 ) under vacuum (5-10 hPa) immediately before MAP fillet packaging (T3).

RESULTS

T3/T2 samples showed the lowest microbial growth after 28 days at 4 °C, with loads up to 1/2.6 log units for Enterobacteria/lactic acid bacteria compared to untreated samples. The initial trimethylamine nitrogen (TMA-N) content (2.6 mg kg^-1 ) increased in T1 and T2/T3 samples by 9.6 and 6/7 units, respectively, after 28 days. Quality Index Method (QIM) better reflected the fish fillets shelf life than texture and colour measurements. The shelf life of T3/T2 samples was established in at least 28 days (4 °C), while the QIM threshold (6) was exceeded after 7/21 days in untreated/T1 fillets.

CONCLUSION

The fish shelf life was extended with vapour OEO treatment using this new technology, similarly to OEO dipping treatment, according to QIM, corroborated by the microbial quality and TMA-N contents. © 2020 Society of Chemical Industry.

Effectiveness of Sodium Alginate Active Coatings Containing Bacteriocin EFL4 for the Quality Improvement of Ready-to-Eat Fresh Salmon Fillets during Cold Storage

This study developed a biopreservation method for ready-to-eat (RTE) fresh salmon fillets based on the use of bacteriocin EFL4 produced by bacteriocinogenic Enterococcus faecalis L04 previously isolated from Chinese sea bass (Lateolabrax maculatus). Bacteriocin EFL4 has the ability to inhibit the growth of several fish-spoilage bacteria and foodborne pathogens, including Staphylococcus aureus, Escherichia coli, Shewanella putrefaciens, Pseudomonas fluorescens and Listeria monocytogenes, and the minimal inhibitory concentration (MIC) for S. putrefaciens was 0.32 μg/mL. The biopreservation potential of bacteriocin EFL4 for RTE fresh salmon fillets during cold storage at 4 °C was tested for the first time on a laboratory scale. Microbiological and physicochemical properties, as well as organoleptic evaluations, have been done during the biopreservation trials. The results show that RTE fresh salmon fillets treated with 0.64 μg/mL bacteriocin EFL4 could significantly (p < 0.05) reduce the total viable count (TVC), total volatile basic nitrogen (TVB-N), K value and maintain the quality of RTE fresh salmon fillets during 8-day storage on the basis of the organoleptic evaluation results.

Characterization of the temperature fluctuation effect on shelf life of an octopus semi-preserved product

The aim of this work is to study the effect of temperature fluctuations on spoilage microbial flora behaviour of a semi-preserved seafood product in modified atmosphere packaging (MAP) as well as to find correct interpretation criteria for simulating temperature fluctuations during storage tests. The study concerned 54 packages of "Octopus carpaccio" that were grouped in three batches and stored at 3 different temperature profiles: the first (16 packages - Group 4°C) was stored at 4±0.5°C; the second (16 packages - Group 8°C) was stored at 8±0.5°C; the third (16 packages - Group F) was stored under a fluctuating temperature regime between 2°C and 14°C. Spoilage microflora, pH and AW has been monitored, at regular intervals, along the storage period (44 days). A predictive model was constructed according to the accredited scientific literature and validated against the observed growth curves of the above three groups. Afterwards, the predictive model has been used setting the temperature at the mean value of fluctuations (6.72°C), at the kinetic mean value of fluctuations (7.80°C) and at the 75th percentile value of fluctuations (11.14°C). The best fitting to the observed data was obtained with the kinetic mean temperature value and this result shows that this parameter can be proposed to reproduce the temperature fluctuation along the distribution and the domestic storage when a storage test has to be carried out.

Use of essential oils and vacuum packaging as a way to extend shelf life of burgers from surimi

Essential oils are known to be a natural preservative due to their antimicrobial and antioxidant properties. The aim of this study was to evaluate an effect of thyme and cumin essential oils (EOs) in combination with air packaging and vacuum packaging on the shelf life of burgers from surimi and chicken meat. The study was conducted at 2°C for 27 days. We tested four groups of samples: (a) burgers in air package, (b) burgers with cumin and thyme EOs in air packaging, (c) burgers in vacuum packaging, and (d) burgers with cumin and thyme EOs in vacuum packaging. The greatest effect (P < 0.001) on the chemical and microbiological characteristics of the novel burgers displayed burgers with EOs of thyme and cumin packaged under vacuum. It can be explained by synergistic effect, which made it possible to extend the shelf life of the burgers. These results allowed us to suggest that surimi could be used as a basic ingredient in burgers production.

Effectiveness of five flavored Tunisian olive oils on Anisakis larvae type 1: application of cinnamon and rosemary oil in industrial anchovy marinating process

BACKGROUND

Anisakidosis is caused by the ingestion of raw or undercooked fish or cephalopods containing viable Anisakis larvae. Several natural extracts, oils, essential oils, and their compounds have been tested against Anisakis. In this study the effectiveness of Tunisian olive oil with different spices or plants (cardamom, cinnamon, ginger, laurel, and rosemary) was tested against Anisakis larvae type 1.

RESULTS

For the in vitro test, larvae were submerged separately in the oils mentioned above and observed to check viability. Cinnamon oil was the most effective against parasites with lethal time (LT) scores being LT50  = 1.5 days and LT100  = 3 days, followed by rosemary. Laurel, cardamom, and ginger oils were less effective. For the ex vivo experiment, cinnamon, and rosemary oils were tested in anchovy fillets, previously artificially parasitized. Cinnamon was the most effective against parasites (dead after 4 days) as compared to rosemary (7 days).

CONCLUSION

The use of cinnamon and rosemary-flavored olive oil in the industrial marinating process can be considered as an efficient alternative to the freezing process required by European Regulation EC No 853/2004 to devitalize Anisakis. © 2019 Society of Chemical Industry.

Chemical Compositions of the Volatile Oils and Antibacterial Screening of Solvent Extract from Downy Lavender

The discovery of a new species exhibiting more effective antibacterial properties is necessary because of the demand on Lavandula species, which continues to increase in a variety of industries. Lavandula pubescens might be a good alternative, as it exhibits strong antibacterial activity. In this study, the chemical composition of the essential oils from different organs (flowers, leaves, stems, and roots) of L. pubescens was identified using gas chromatography-mass spectrometry. Furthermore, the antimicrobial activities of different solvent extracts (methanol, ethanol, diethyl ether, hexane, and ethyl acetate) and different organ (flower, leaf, stem, and root) extracts of L. pubescens were evaluated. Only the ethyl acetate extracts of L. pubescens exhibited antibacterial activity against all bacterial strains tested, including Staphylococcus haemolyticus, Escherichia coli (KF 918342), Aeromonas hydrophila (KCTC 12487), E. coli (ATCC 35150), Cronobacter sakazakii (ATCC 29544), and Aeromonas salmonicida (KACC 15136). In particular, the extracts exhibited significant activity against S. haemolyticus. Ethyl acetate extract of the leaf exhibited the best activity against all bacterial strains. This study provides valuable information on the chemical compositions in essential oils and antimicrobial properties of L. pubescens.

Natural Preservatives for Extending the Shelf-Life of Seafood: A Revisit

Consumer demand for minimally processed seafood that retains its sensory and nutritional properties after handling and storage is increasing. Nevertheless, quality loss in seafood occurs immediately after death, during processing and storage, and is associated with enzymatic, microbiological, and chemical reactions. To maintain the quality, several synthetic additives (preservatives) are promising for preventing the changes in texture and color, development of unpleasant flavor and rancid odor, and loss of nutrients of seafood during storage at low temperature. However, the use of these preservatives has been linked to potential health hazards. In this regard, natural preservatives with excellent antioxidant and antimicrobial properties have been extensively searched and implemented as safe alternatives in seafood processing, with the sole purpose of extending shelf-life. Natural preservatives commonly used include plants extracts, chitosan and chitooligosaccharide, bacteriocins, bioactive peptides, and essential oils, among others. This review provides updated information about the production, mode of action, applications, and limitations of these natural preservatives in seafood preservation.

Use of Tunisian flavored olive oil as anisakicidal agent in industrial anchovy marinating process

BACKGROUND

Natural compounds are more frequently used against Anisakis, responsible for the important fish-borne disease anisakidosis. The aim of the study was to evaluate the effectiveness of enriched Tunisian olive oil with different spices (cumin, turmeric, clove, thyme, and lemon) against Anisakis larvae type 1.

RESULTS

In vitro experiment: larvae were submerged separately in the aforementioned oils and then examined to check viability. For each oil, LT50 and LT100 were calculated. Turmeric and cumin oils are the most effective against the parasites; followed by lemon, thyme and clove oils. For the in vivo experiment, turmeric and cumin oils were tested in anchovy fillets previously artificially parasitized with L3 larvae. Cumin was the most effective against parasites (dead after 5 days) compared with turmeric (8 days). For the two oils, the resulting odor was pleasant, as was the taste, while changes in color were much more evident in turmeric fillets.

CONCLUSION

All the flavored oils demonstrated a good nematodical action against Anisakis. Cumin oil was the most effective against encysted larvae. Turmeric oil showed the best activity in the in vitro experiment. The use of flavored oils in the marinating process could represent an efficient strategy to devitalize Anisakis. © 2017 Society of Chemical Industry.

A New Approach to Predict the Fish Fillet Shelf-Life in Presence of Natural Preservative Agents

Three data sets concerning the behaviour of spoilage flora of fillets treated with natural preservative substances (NPS) were used to construct a new kind of mathematical predictive model. This model, unlike other ones, allows expressing the antibacterial effect of the NPS separately from the prediction of the growth rate. This approach, based on the introduction of a parameter into the predictive primary model, produced a good fitting of observed data and allowed characterising quantitatively the increase of shelf-life of fillets.

Activity of Tagetes minuta Linnaeus (Asteraceae) essential oil against L3 Anisakis larvae type 1

OBJECTIVE

To evaluate in vitro effects of Tagetes minuta L. essential oil (TEO) on L3 Anisakis larvae type 1.

METHODS

In order to evaluate the potential use of Tagetes minuta essential oil against L3 Anisakis larvae three different media were tested: 1) a saline solution (SS); 2) an industrial marinating solution (MS); 3) sunflower seeds oil (SO). For each media and concentrations of TEO (0.1%, 0.5%, 1.0% and 5.0% v/v), 20 parasites were introduced into plastic Petri dishes (diameter 90 mm) and maintained at room temperature. As controls, larvae were maintained without TEO under identical experimental conditions in SS, MS and SO. A total of 900 larvae were tested. The normalized mean viability, LT100, LT50 and the percentage of inactivation at 24 h were calculated.

RESULTS

In vitro tests revealed a complete inactivation of parasites in saline solution after 2 h with 5% and 1% of TEO. In marinating solution, a complete inactivation of parasites was observed after 4 h at all concentrations used. A slower activity for all TEO concentration was reported in SO.

CONCLUSIONS

The results obtained, showing a strong activity against Anisakis larvae, confirm TEO as a larvicidal agent in the treatment of human anisakidosis and in the industrial marinating process.