Quality assessment of Mediterranean horse mackerel (Trachurus mediterraneus) and blue jack mackerel (Trachurus picturatus) during storage in ice

Sensory, physicochemical and microbiological analyses were carried out on Mediterranean horse mackerel and blue jack mackerel in order to determine quality changes during storage in ice. Sensory results indicated that whole Mediterranean horse mackerel and blue jack mackerel used in this trial had a shelf-life of 10 and 7 days, respectively. Fishtester and Fishchecker measurements showed that the quality of blue jack mackerel had deteriorated more rapidly. Fishtester values of the blue jack mackerel and the Mediterranean horse mackerel were reduced from 59 ± 10.1 to 14.8 ± 2.8 and from 85.3 ± 13.2 to 25.6 ± 7.8, respectively during the storage time. Fishchecker gave red sign (unfit for consumption) for first time on day 7 and day 6 in Mediterranean horse mackerel and blue jack mackerel, respectively. The pH of Mediterranean horse mackerel muscle was consistently lower than the pH of blue jack mackerel muscle during the storage period. The pH values of both species muscle increased gradually with time and pH value equal to 7 had almost coincided with the end of shelf-life. Bacterial loads in both fish species muscle remained rather low prior to day 10 (<6 log₁₀ cfu/g). The longer shelf-life of Mediterranean horse mackerel as determined by sensory evaluation was not reflected in microbiological results suggesting that the difference was due to lower rate of autolysis rather than to reduced microbial activity.     

A COIBar-RFLP strategy for the rapid detection of Engraulis encrasicolus in processed anchovy products

The species identity on anchovy products was tested through COI mitochondrial DNA sequences analysis in 50 samples belonging to 20 different commercial lots, such as anchovy fillets in vegetal oil, canned anchovies and anchovy paste. Seven samples (14%) were found to be not from Engraulis encrasicolus meats, confirming concerns of species substitution. Conventional COI-DNA barcoding revealed the presence of four different species, E. encrasicolus, Engraulis japonicus, Sardinella aurita and Sardina pilchardus, in the processed products labeled as European anchovy. The DNA barcoding was then used in combination with PCR-RFLP method to investigate labeling accuracy in processed anchovy products and to unveil putative fish fraud involving the replacement of the European anchovy, E. encrasicolus, with less valuable Engraulidae and Clupeidae species. We applied a COIBar-RFLP (Cytochrome Oxidase I Barcode-Restriction Fragment Length Polymorphism) analysis that yielded differential patterns allowing the unambiguous discrimination of European anchovy from the other species tested. The proposed molecular strategy relies on the efficiency of COI as a DNA barcode and proved very efficient and less expensive than DNA sequencing strategies. This approach may be useful in routine controls, especially in cases of large-scale sample screening.     

High contents of cadmium,lead, zinc and copper in popular fishery products sold in Turkish supermarkets

Selected toxic (cadmium, lead) and essential (zinc and copper) trace metals were determined by means of differential pulse stripping anodic voltammetry (DPSAV) in some different brands and kinds of fishery products purchased from the popular supermarkets of Turkey. Among the fishery products, the highest concentration of cadmium, lead, zinc and copper were found in the frozen anchovy (494.2 μg/kg, 314.2 μg/kg, 566 mg/kg, 45.7 mg/kg, respectively). While the canned anchovy fillet had the lowest cadmium (25.1 μg/kg), zinc (33.8 mg/kg) and copper (7.1 mg/kg) concentrations, canned tuna fish (Brand A) had the lowest lead (76.1 μg/kg). The concentrations of all toxic and essential elements in the selected products were high and often exceeded legal limits set by health authorities. Therefore these products must be monitored more often.     

NIR spectroscopy: A non-destructive fast technique to verify heat treatment of fish-meat gel

Attempts have been made to assess previous heat treatment of fish-meat gels prepared from walleye pollack and horse mackerel surimi, since surimi-based products have been gaining popularity for their protein quality, law fat content and convenience in consumption. Visible–NIR spectra of gels (30–90 °C) were collected from 650 to 1100 nm with a surface interactance fibre optic accessory. Partial least squares (PLS) and multiple linear regression (MLR) techniques were employed for data analysis. Spectral changes upon heat treatment were related to the heating temperature which reflected the changes in the environment of the secondary structure due to the denaturation of proteins, and to changes in the state of water. A promising linear relationship (R = 0.98) was observed between NIR-predicted temperatures and the actual heating temperatures with prediction error of 1.85 °C.     

Seasonal variation in the chemical composition and microbiological condition of Mediterranean horse mackerel (Trachurus mediterraneus) muscle from the North Aegean Sea (Greece)

The aim of this work was to determine the chemical composition and microbiological quality of Mediterranean horse mackerel (Trachurus mediterraneus) muscle during the year and the consequent advantages or disadvantages in processing the raw material. A total of 180 samples were examined (15 samples per month) during two years (November 2001–November 2003). Fish were caught in the coastal waters of Chalkidiki peninsula (Northern Greece). Proximate composition of the muscle during the year resulted in: water 76.8 ± 1.39%, proteins 20.3 ± 0.68%, fat 1.3 ± 1.08% and ash 1.5 ± 0.08%. In March, April and May an increase in fat content of the muscle (2.5%, 2.8% and 2.1%, respectively) and a decrease in water content of the muscle (below 75.9%) were observed. On the contrary, fat content showed a decrease in September and October (0.4% and 0.6%, respectively), while water content of the muscle increased during these months (78.2% and 77.6%, respectively). The protein content of the muscle remained at high values, while the ash content was almost constant during the year. The mean value of muscle pH was 6.38 ± 0.16; extreme values (<6 or >7) of muscle pH were not observed. Total Viable Bacteria, Shewanella putrefaciens and Pseudomonas spp. were used as microbial indices to evaluate the microbiological quality of the muscle. Mean counts of Total Viable Bacteria, S. putrefaciens and Pseudomonas spp. during the year were: 4.01 ± 0.38 log₁₀ cfu/g, 2.37 ± 0.43 log₁₀ cfu/g and 3.34 ± 0.27 log₁₀ cfu/g, respectively. The variations of the values within seasons are minimal and significant homogeneity in the chemical composition and microbiological quality of Mediterranean horse mackerel muscle is observed. This is an important advantage in processing of the raw material.     

Development and application of molecular markers for poultry meat identification in food chain

Every year, large quantities of poultry and game meat are consumed. Thus, efficient techniques to identify the meat species origin are required which interest traders, consumers and organizations. In this study, two mitochondrial DNA (mtDNA) genes, Cytochrome b (Cyt b) and 12S ribosomal RNA (12S rRNA) were tested as putative discrimination markers in samples of raw and processed poultry meat (chicken, turkey, duck, goose, pheasant, partridge, woodcock, ostrich, quail and song thrush), applying the PCR–RFLP technique with universal primers and ten different restriction enzymes. Digestion of 12S rRNA by AciI successfully distinguished all avian species, producing species-specific patterns. We conclude that the 12S rRNA gene is more informative than Cyt b gene for avian species identification purposes. Moderate process treatment did not prevent the species identification, presenting similar patterns with the raw meat. Finally, this method was considered sufficient to detect mixtures of meat, making it a valuable tool for checking possible adulterations.     

Meat species identification based on the loop mediated isothermal amplification and electrochemical DNA sensor

An easy, rapid and sensitive method of detection of the presence of meat species in raw or processed foods is important from cultural, religious, health and commercial perspectives. In this study we have tried to distinguish species-specificity in control and processed pork, chicken and bovine meats using loop mediated isothermal amplicons (LAMP) and disposable electrochemical printed (DEP) chips. LAMP is a nucleic acid amplification method that amplifies target DNA with high specificity, efficiency and rapidity under isothermal condition (63 °C). Electrochemical genosensor with the DEP chips detects the amplicons by Linear Sweep Voltammetry (LSV) observation of DNA–Hoechst33258 interaction on the chip surface. Hoechst33258 interacts with DNA in solution without immobilization of DNA onto the electrode surface eliminating the time consuming probe immobilization step. Our method is more specific and free of unwanted amplifications compared to Multiplexed PCR (M-PCR) method and gave limits of detection of ∼20.33 ng/μl (3 × 10⁴ copies/reaction), ∼78.68 pg/μL (3 × 10² copies/reaction) and ∼23.63 pg/μL (30 copies/reaction) for pork, chicken and bovine species, respectively. Our method of detection is quick, taking only an hour, and it may be useful for food administration laboratories to carry out meat species identification in raw and processed foods.     

Inhibition of biogenic amine formation in a salted and fermented anchovy by Staphylococcus xylosus as a protective culture

This study was carried out to reduce biogenic amine contents in Myeolchi-jeot, a salted and fermented anchovy (Engraulis japonicus). The effects of potential starter cultures on the degradation of histamine and tyramine were determined by HPLC analysis. Out of seven potential starter cultures tested, Staphylococcus xylosus No. 0538 possessed not only the greatest capability to degrade histamine, but a detectable ability to degrade tyramine as well. In a phosphate buffer containing 0.5 mM histamine and 0.5 mM tyramine, 38.0% of the histamine and 4.4% of the tyramine were degraded by resting cells of the S. xylosus No. 0538 within 24 h. The other cultures tested had less or no effect in degrading histamine and tyramine. The S. xylosus No. 0538 was also found to produce bacteriocin-like inhibitory substance(s) and have the highest antimicrobial activity against Bacillus licheniformis strains defined as amine producers. Finally, the S. xylosus No. 0538 was used as starter culture and applied to the ripening of Myeolchi-jeot, and then overall production of biogenic amines was reduced by 16.0%, compared to control. Consequently, the findings of this study are expected to enhance the safety of not only Myeolchi-jeot but other salted and/or fermented anchovy products.     

A novel common primer multiplex PCR (CP-M-PCR) method for the simultaneous detection of meat species

A novel common primer multiplex PCR (CP-M-PCR) was applied to detect four kinds of meats (chicken, cattle, pig and horse) as raw materials. A common adapter was designed in the 5′-end of species-specific reverse primers which matched with the species-specific DNA sequences for each species and also used as the common primer (CP). CP-M-PCR primers were designed to uncover different length fragments of 239, 292, 412, and 451 bp from chicken, cattle, pig and horse meats, respectively. The bands of specific DNA fragments amplified by CP-M-PCR method still appeared until the concentration of species-specific primers diluted to 0.015 pmol and primer sensitivity was increased by 100 times compared with conventional multiplex PCR without CP. CP-M-PCR detection limit of the DNA samples was 0.1 ng (36.4 copies) for single kind of meat as well as four kinds of meats. CP-M-PCR method simplified the PCR reaction system and conquered the disparate amplified efficiency from different primers. The CP-M-PCR method could be widely applied in practical detection for simultaneous identification of other meat species and their products.     

Mycotoxin occurrence in beer produced in several European countries

The occurrence of ochratoxin A, trichothecenes, fumonisins and aflatoxins in a sample of 106 beers produced in several European countries, was investigated. The analyses were conducted using high-performance liquid chromatography with fluorimetric detection for ochratoxin A and aflatoxins, gas-chromatography and high-performance liquid chromatography, both coupled with mass spectrometer, for trichothecenes and fumonisins, respectively. Aflatoxins were not detected in any samples, whereas ochratoxin A, deoxynivalenol and fumonisins were found in a relatively high number of samples. Their presence was at low levels in all samples; however, some differences were observed between the European countries. As regards ochratoxin A, beer samples from southern Europe showed levels always lower than 0.040 μg l^?1, while the samples from other European countries showed significantly higher values, up to 0.189 μg l^?1 (P < 0.001). For fumonisins, the levels of Italian beers were significantly higher compared to the samples from other countries (P = 0.006).     

Presence of aflatoxin M1 in milk and infant milk products in Tehran,Iran

Aflatoxins are highly toxic, mutagenic, teratogenic and carcinogenic compounds. The purpose of this survey was to determine natural occurrence and level of AFM₁ in pasteurized liquid milk, infant formula and milk-based cereal weaning food consumed in Tehran, Iran.A total of 328 branded milk products and liquid milk samples were collected and investigated by Enzyme Linked Immuno Sorbent Assay (ELISA).The samples of pasteurized liquid milk (n = 128), infant formula (n = 120) and milk-based cereal weaning food (n = 80) showed that the incidence of contamination with AFM₁ is 96.3%, the presence of AFM₁ in each group was 72.2 ± 23.5, 7.3 ± 3.9 and 16.8 ± 12.5 ng/kg, ranging between 31–113, 1–14 and 3–35 ng/kg, respectively.In general, the amount of AFM₁ in 100 (78%) of liquid milk samples and 24 (33%) of milk-based weaning food was higher than the maximum tolerance limit accepted by European Union, but in all of the infant formula samples was lower (European Communities and Codex Alimentarius has prescribed a limit of 50 ng/kg for AFM₁ in milk and 25 ng/kg in infant milk products).     

A potential methodology for differentiation of ciguatgoxin-carrying species of moray eel

A food poisoning incident due to ingestion of an unknown moray eel occurred in Taiwan. To identify the species of causative moray eel implicated in food poisoning, a 376-bp fragment sequence of cytochrome b gene was successfully obtained from four species of moray eel by using a pair of primers (L newest-1/H 15149). This fragment could be amplified using fish meat treated with different heating processes (100 °C for 30 min, 100 °C for 60 min, 121 °C for 15 min, and 121 °C for 30 min). After sequencing, it was found that no variation in sequence was detected among individuals within each species. The species of causative moray eel implicated in food poisoning was judged as Gymnothorax javanicus based on sequence analysis. In addition, using restriction enzyme analysis, including Taq I and Sau96 I, could distinguish these four species of moray eel and identify the fish species of poisoning sample as G. javanicus. The toxicity of viscera in 24 specimens of four moray eel species was not detected, but the food poisoning sample was found to be toxic. Overall, this study proved that DNA sequence and restriction enzyme analyses are useful in identifying that the causative moray eel species was G. javanicus.     

Molecular identification of grouper species using PCR-RFLP technique

A PCR-RFLP method was used to identify five species of raw and processed groupers belonging to the genus, Epinephelus viz. E. areolatus, E. bleekeri, E. faveatus, E. longispinis and E. undulosus. DNA extracted from all the species using phenol-chloroform method amplified the mt 16S rRNA gene, unique for the genus, Epinephelus, using GenF and EpiR primers at 300 bp. This fragment did not amplify the DNA of even closely related grouper genus, Cephalopholis, making the method more specific the grouper genus, Epinephelus. The specificity was further ascertained by performing the internal control that targeted 18S rRNA, which was eukaryotic specific. Digestion of PCR products with three selected restriction enzymes viz. SduI, BciVI, and Sau3AI followed by PAGE yielded species specific patterns that enabled identification of three grouper species viz. E. bleekeri, E. faveatus and E. longispinis, while the other two species viz. E. areolatus and E. undulosus gave similar pattern in the gel, although minor variations in the molecular sizes of digested products were noticed. Chilled, frozen and cooked groupers also gave similar PCR-RFLP pattern to that of raw groupers making this method suitable even for processed products.     

Biofilm-forming ability and resistance to industrial disinfectants of Staphylococcus aureus isolated from fishery products

Adhesion and biofilm-forming ability of twenty six S. aureus strains previously isolated from fishery products on stainless steel was assessed. All strains reached counts higher than 10⁴ CFU/cm² after 5 h at 25 °C. Most strains also showed a biofilm-forming ability higher than S. aureus ATCC 6538 – reference strain in bactericidal standard tests – by crystal violet staining. In addition, it seems that food-processing could have produced a selective pressure and strains with a high biofilm-forming ability were more likely found in highly handled and processed products.The efficacy of the industrial disinfectants benzalkonium chloride (BAC), sodium hypochlorite (NaClO) and peracetic acid (PAA) against biofilms and planktonic counterparts was also examined in terms of minimum biofilm eradication concentration (MBEC) and minimum bactericidal concentration (MBC), respectively. Biofilms showed an antimicrobial resistance higher than planktonic cells in all cases. However, no correlation was found between MBEC and MBC, likely due to differences in biofilm extracellular matrix (composition, content and architecture) between strains. BAC resistance increased as biofilms aged. Generally, biofilm formation seemed to attenuate the effect of low temperatures on BAC resistance. PAA was found to be most effective against both biofilms and planktonic cells, followed by NaClO and BAC. Resistance did not follow the same order for each biocide, which remarks the need of using a wide collection of strains in standard tests of bactericidal activity to ensure a proper application of disinfectants. Doses recommended by manufacturers for BAC, PAA and NaClO to disinfect food-contact surfaces were lower than doses for complete biofilm removal (i.e. MBEC) under some environmental conditions common in the food industry, which questions bactericidal standard tests and promotes the search for new strategies for biofilm removal.     

Analysis of ethyl carbamate in Korean soy sauce using high-performance liquid chromatography with fluorescence detection or tandem mass spectrometry and gas chromatography with mass spectrometry

A specific, sensitive procedure involving high-performance liquid chromatography (HPLC) coupled to tandem mass spectrometry (MS/MS) was developed and compared to other analytical methods for quantification of ethyl carbamate (EC) in Korean soy sauce products. HPLC with a fluorescence detector was not applicable for monitoring trace amounts of EC in soy sauce due to its low detection limit (20 ppb). The use of gas chromatography (GC) coupled to MS could be applied to soy sauce, but it was not as simple and fast as HPLC/MS/MS. The GC/MS procedure exhibited excellent linearity over the concentration range of 10–200 ppb with a 0.5 ppb limit of detection (LOD) and 82.7 ± 3.1% recovery. A procedure involving HPLC/MS/MS with multiple reaction monitoring was developed. The characteristic transitions of m/z 90 → 62 for EC as well as m/z 104 → 62 for propyl carbamate (PC) as the internal standard were monitored. Good linearity was obtained both in the range from 10 to 100 ppb and in the range from 0.1 to 20 ppb with a LOD of 0.05 ppb. The average recovery was 92.2 ± 1.7%. The applicability of the GC/MS and developed HPLC/MS/MS methods was demonstrated by detection of EC in 12 kinds of commercial Korean soy sauce products at levels of 0.5 and 0.1 ppb, respectively. The new HPLC/MS/MS method provided greater sensitivity with a simpler and shorter confirmatory analysis than the GC/MS method.     

Improvement of the hygienic quality of wet ‘fufu’ produced in South West Nigeria

To improve the hygienic quality condition of wet ‘fufu’, an indigenous fermented cassava product produced in South-West Nigeria, the processing facilities were upgraded and GMP implemented before HACCP application in processing plants in Abeokuta. The effectiveness of the GMP and HACCP was assessed by monitoring the environment and ‘fufu’ production. Air sampling and swabbing of equipment surfaces revealed a microbiota which was consistent with the fermented product. The results before application of GMP and HACCP showed the predominance of Staphylococcus aureus in the wet ‘fufu’ samples ranging between 1.1 × 10⁴ cfu/g and 2.5 × 10⁵ cfu/g. Monitoring after application showed that the raw materials, products, processing parameters conformed to the critical limits within which the safety of the food product would be ensured. This was confirmed by the results of laboratory analysis of raw materials, intermediary and final products. Escherichia coli, Staphylococcus aureus, and Salmonella were not detected in any of the finished product. Application of GMP and HACCP was therefore found to be effective as a quality management system for assuring the safety of traditionally processed wet ‘fufu’.     

Superheated steam reduction of deoxynivalenol in naturally contaminated wheat kernels

Contamination of wheat with the Fusarium mycotoxin deoxynivalenol (DON) is a concern to the ethanol industry as it is stable during most processing operations and will be concentrated in the spent grains, which are potentially a valuable feedstock. Superheated steam at four processing temperatures (110, 135, 160, and 185 °C), three steam velocities (0.65, 1.3, and 1.5 m/s), and processing times of 2–15 min were used to treat wheat kernels naturally contaminated with DON to find the best processing parameters for the reduction of DON. A commercial enzyme-linked immunosorbent assay (ELISA) kit was used to determine DON levels in the wheat samples. Samples became increasingly toasted, displaying a brown color with increasing processing temperatures and times, and became friable after processing at temperatures of 160 and 185 °C. Only samples processed at 185 °C and 1.3 m/s exhibited any starch gelatinization. Significant (P < 0.05) reductions in DON levels were seen at 160 and 185 °C but were not generally seen at 110 and 135 °C and the effect of velocity was not significant (P > 0.05). Reductions of up to 52% were achieved at 185 °C and 6 min processing time and were due only to thermal degradation and not to solubilization and extraction.     

Incidence and level of patulin contamination in pure and mixed apple juices marketed in Italy

A survey on the occurrence of patulin was conducted during 2005 on commercial pure apple juices (53 samples) and mixed apple juices (82 samples) marketed in Italy. The current study was undertaken to investigate the possible influence of the agro-food production process employed (conventional or organic), of the fruit percentage in the commercial product (higher or lower than 50%) and of the type of apple juice (clear or cloudy) on the occurrence and level of patulin contamination. Patulin could be quantified in 34.8% of the samples ranging from 1.58 to 55.41 μg kg⁻¹. With the exception of one sample, the level of patulin was lower than 50 μg kg⁻¹, the maximum permitted threshold in fruit juices according to the European legislation. Mean levels of patulin were significantly lower in mixed apple juices (4.54 μg kg⁻¹) than in pure apple juices (9.32 μg kg⁻¹). Levels of patulin contamination were comparable in clear and cloudy juices. A similar incidence of positive samples was found in conventional and organic apple based juices, and the magnitude between the mean contamination levels, although higher in organic (10.92 μg kg⁻¹) than in conventional juices (4.77 μg kg⁻¹), was not statistically significant (p = 0.771; Mann–Whitney test). The magnitude between the means of patulin contamination in juices containing more than 50% fruit (11.26 μg kg⁻¹) and in juices with 50% or less fruit (3.35 μg kg⁻¹) was statistically significant (p = 0.016; Mann–Whitney test).     

Microbiological quality of legume-based traditional fermented foods marketed in West Bengal,India

A total of 105 samples of six different types of legume-based popular fermented foods, namely amriti, dhokla, dosa, idli, papad and wadi, purchased from retail outlets in West Bengal, was analysed to determine their microbiological safety status. While dhokla and idli were of high-moisture foods (62 g (100 g)⁻¹), others had a lower moisture level (14–27 g (100 g)⁻¹). Papad was alkaline (pH 8.7), whereas all the other foods were acidic (pH 4.4–5.8). Every sample was found contaminated with total aerobic mesophilic bacteria (detection limit, 10 cfu g⁻¹); 38% (40/105) of the samples contained more than 10⁶ cfu g⁻¹. Aerobic mesophilic bacterial spores were found in 88% (92/105) of the samples (detection limit, 100 cfu g⁻¹), whereas their anaerobic counterparts were present in 39% (41/105) of the samples (detection limit, 10 cfu g⁻¹). Although all the samples, excepting one, were free from Staphylococcus aureus (detection limit, 100 cfu g⁻¹), 20% (21/105) of the samples were found contaminated with Bacillus cereus (detection limit, 100 cfu g⁻¹). Enterobacteriaceae were found in 46% (48/105) of the samples (detection limit, 10 cfu g⁻¹). Of the Enterobacteriaceae isolates, 92% were coliforms and 57% were faecal coliforms. Escherichia coli (detection limit, 10 cfu g⁻¹) was found in only one sample each of wadi and idli, at a load of 10³–10⁴ g⁻¹. Salmonella (detection limit, 1 cell (25 g)⁻¹) occurred in 12 samples of wadi, idli and papad, however was absent in the other three products. Clostridium perfringens (detection limit, 10 cfu g⁻¹) and Shigella (detection limit, 1 cell (25 g)⁻¹) could not be detected. The results obtained in the present study indicated that these foods were manufactured using poor-quality starting materials, processed under unhygienic conditions, or/and temperature-abused during transportation and storage. Based on these results, a guideline is recommended for obtaining safe products.     

Paralytic toxins in four species of coral reef crabs from Kenting National Park in southern Taiwan

Paralytic toxicity was detected by tetrodotoxin (TTX) bioassay in 41 specimens of four species of coral reef crabs collected from Kenting National Park, southern Taiwan from January 2003 to March 2004. The frequency of toxicity in Zosimus aeneus, Xanthias lividus, Actaeodes tomentosus (Xanthidae family) and Camposcia retusa (Majidae family) specimens was 93.3%, 100%, 46.7% and 66.7%, respectively. The average toxicity of crab specimens was 483 ± 225 (mean ± SD) mouse units (MU) for Z. aeneus, 51 ± 32 MU for X. lividus, 6 ± 5 MU for A. tomentosus, and 18 ± 11 MU for C. retusa. Each toxin of four species of crabs was extracted with acidic methanol, cleansed using a C18 solid-phase extraction column, filtered through a microcentrifuge filter and analyzed by HPLC, LC-MS and GC-MS. The toxins of Z. aeneus and X. lividus contained TTX (90%) and a small amount of gonyautoxins (10%), whereas those of A. tomentosus and C. retusa all mainly contained TTX, but no paralytic shellfish poison. Except for Z. aeneus and X. lividus, two species A. tomentosus and C. retusa were first recorded as toxic in Taiwan.