Monitoring the contents of biogenic amines in fish and fish products consumed in Korea

In order to obtain the level of biogenic amines in fish and fish products, a reversed phase high performance liquid chromatographic method was used for the quantitation of 12 biogenic amines in 300 fish and 80 fish products in Korea. Biogenic amines were extracted with hydrochloric acid, derivatized with dansyl chloride, separated using gradient elution, and detected by photodiode array and all detected biogenic amines were identified by UPLC/MS/MS. The detection levels of biogenic amines in the sample ranged from ND (not detected) to 30.6 mg/kg for agmatine, from ND to 390.0 mg/kg for cadaverine, from ND to 19.8 mg/kg for dopamine, from ND to 70.1 mg/kg for histamine, from ND to 17.8 mg/kg for noradrenaline, from ND to 29.7 mg/kg for 2-phenylethylamine, from ND to 43.0 mg/kg for putrescine, from ND to 11.9 mg/kg for serotonin, from ND to 9.5 mg/kg for spermidine, from ND to 13.5 mg/kg for spermine, from ND to 12.8 mg/kg for tryptamine, and from ND to 67.7 mg/kg for tyramine. Anchovy samples showed the high levels of histamine from 15.2 to 70.1 mg/kg, putrescine from 9.1 to 43.0 mg/kg, cadaverine from 152.2 to 90.0 mg/kg, and tyramine from 27.1 to 67.7 mg/kg. Agmatine was found at 30.6 mg/kg in cuttlefish. In the others fish samples agmatine detection levels were in the range from ND to 27.2 mg/kg. Spermidine and dopamine were detected about more than 85% samples in the range from ND to 19.3 mg/kg. Most of fish product samples showed less than 20 mg/kg of each biogenic amine. The maximum histamine and tyramine detection levels were respectively less than those of the regulation and recommendation.     

Chemical characterisation, biogenic amines contents, and identification of fish species in cod and escolar steaks, and salted escolar roe products

Forty-one cod steaks, fifteen escolar steaks, and fifteen salted escolar roe products sold in Taiwan market were purchased and tested to determine the biogenic amine, histamine-forming bacteria, and identification of fish species. The levels of pH value, salt content, Aw, TVBN and APC in all samples ranged from 5.3 to 7.0, 0.7 to 5.6%, 0.80 to 0.99, 0.8 to 59.9 mg/100 g and 2.5 to 7.3 log CFU/g, respectively. None of these samples contained coliform bacteria and Escherichia coli. The average content of histamine in all samples was less than 5 mg/100 g US Food and Drug Administration guideline value. Nine histamine-forming bacterial strains isolated from cod, escolar, and salted escolar roe samples produced 2.0-62.3 ppm of histamine in trypticase soy broth (TSB) supplemented with 1.0% l-histidine (TSBH). Assay of DNA direct sequence and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) revealed that mislabeling rate of 41 cod steaks was 31.6% (13/41). Among them, 7 samples (17%) and 6 samples (14.6%) were identified as Ruvettus pretiosus (oilfish) and Reinhardtius hippoglossoides (Greenland halibut), respectively. In addition, most of escolar steaks and salted escolar roe products were identified as Lepidocybium flavobrunneum (escolar), while other samples were identified as R. pretiosus.     

Monitoring the contents of biogenic amines in sufu by HPLC with SPE and pre-column derivatization

Sufu is a nutritious fermented food whose consumption is currently increasing in many countries. The purpose of this study was to develop an HPLC method with SPE and pre-column derivatization for monitoring the content of biogenic amine in sufu and to understand the differences in the contents of biogenic amines with different processing technologies. Biogenic amines in sufu were extracted with 6% trichloroacetic acid, derivatized with 4-chloro-3,5-dinitrobenzotrifluoride, purified with Waters Oasis MCX cartridge, separated by HPLC using gradient elution, and detected by spectrophotometric UV at 254 nm. The method linearity, calculated for each biogenic amine, has a correlation coefficient higher than 0.9915. Detection limits of the biogenic amines were ranged from 0.016 mg/kg for putrescine to 0.067 mg/kg for spermine. Spiking experiments showed that the overall recoveries ranged between 83.6% and 103.5% with relative standard deviations of 1.26–5.24%. Of the seven biogenic amines under study, at least four biogenic amines were detectable in different kinds of sufu. Tryptamine, putrescine, histamine, and tyramine were the most prevailing biogenic amines in all sufu samples. The mean values of histamine, tryptamine, phenylethylamine, tyramine, putrescine, spermidine and spermine determined in samples were found to be 18.2 mg/kg, 39.0 mg/kg, 1.1 mg/kg, 21.7 mg/kg, 34.6 mg/kg, 11.1 mg/kg, and 8.7 mg/kg, respectively. The total contents of biogenic amines in bacteria fermented sufu samples (129.0 mg/kg) were slightly lower than those in enzymatically ripened sufu samples (137.7 mg/kg). The concentrations of biogenic amines detected in sufu samples were below the maximum permissible limits.     

Biogenic amines in commercial fish and fish products sold in southern China

Eight biogenic amines (histamine, tryptamine, putrescine, 2-phenylethylamine, cadaverine, tyramine, spermidine and spermine) were determined in 13 species of fish and 49 fish products commonly consumed in southern China. The biogenic amines were analyzed by reverse phase HPLC with a fluorescence detector following pre-column derivation with dansyl chloride. In the fish samples, the total level of biogenic amine (BA) ranged from 5.03 mg/kg to 156.17 mg/kg, with a mean value of 44.17 mg/kg. Histamine levels were less than 21.85 mg/kg. The BA levels detected were not high enough to indicate fish decomposition. Low BA levels were also found in most fish product samples. However, several samples of fermented fish products and packaged fish products showed higher levels (484.42 mg/kg of BA in lightly cured horse mackerel and 166.45 mg/kg of BA in packaged eel). Specifically, lightly cured horse mackerel, which is a traditional fish product in southern China, exhibited relatively high levels of 2-phenylethylamine (57.61 mg/kg), cadaverine (244.41 mg/kg) and tyramine (62.85 mg/kg). Such samples with relatively high BA content require careful monitoring to ensure their safety for human consumption.     

Genetic screening of biogenic amines production capacity from some lactic acid bacteria strains

There is an increasing interest for using lactic acid bacteria (LAB) as a starter and adjunct cultures for producing novel foods with particular functional traits. The ability of the starter to produce biogenic amines (BA) should be taken into account wherein protective starters should be selected to avoid hygienic and toxicological risks. This work aimed to study the possibilities of forming BA (histamine, putrescine, agmatine and tyramine) from thirty two LAB strains belonging to species of the genera Lactobacillus and Streptococcus that used in food products as well as strains isolated from healthy breast-fed infants. The analytical protocol involved using polymerase chain reaction (PCR) and thin layer chromatography (TLC) techniques to determine the ability of LAB strains to form BA. The presence of key genes involved in the biosynthetic pathways of the BA was also assessed by PCR. Six LAB strains gave positive results for putrescine production wherein the maximum level was 14.6 mg/kg. Six strains gave positive results for histamine production (maximum level was 31.7 mg/kg) and were positive for the presence of histidine decarboxylase (HDC) gene. Seven strains exhibited positive results for tyramines production (maximum level was 2.85 mg/kg) and were positive for the presence of tyrosine decarboxylase (TDC) gene. Eight strains gave positive results for agmatine production (maximum level was 174.5 mg/kg) and were positive for the presence of dihydrolase (deiminase) gene that responsible for agmatine formation. It could be concluded that the microorganisms used in food and dairy production should be screened carefully by PCR for their ability to produce BA.     

Reduction of biogenic amines and aflatoxins in Doenjang samples fermented with various Meju as starter cultures

The objective of this study was to determine the contents of biogenic amines (BAs) and aflatoxin levels in laboratory-made starter culture soybean fermented samples of Doenjang. Various starter cultures of Meju, made by using different microbial strains, were used for the production of Doenjang samples under standardized fermentation/manufacturing conditions, and the contents of BAs and aflatoxins were analyzed. Determination of nine different BAs and total aflatoxin was carried out by high performance liquid chromatography and immunoassay-based total aflatoxin detection kit, respectively. It was found that the amount of BAs in all laboratory-made starter culture Doenjang samples was within the limit of human consumption safety level. Also the level of total aflatoxin was under the limit, according to the standard parameters of FAO/WHO.     

Investigation of undeclared food allergens in commercial Thai food products

This study investigates the presence of undeclared allergens - namely milk, egg, wheat and peanut - in commercial processed food products in Thailand. Out of 142 commercial products, 55 positive cases were found (by quantitative ELISA method) to contain an undeclared allergen greater than 10 ppm. Among all positive products, undeclared milk appeared the most frequently (21 cases), followed by egg and wheat with similar frequency (17 cases), while peanut was rarely found. Milk- or egg-positive products were further confirmed by the presence of the milk protein, casein, or the egg protein, ovalbumin, by Western blot test. Our results should help to increase the awareness among Thai food manufacturers of the need for more careful management of allergenic food ingredients, and to encourage the labeling of allergen information for allergic consumers, thus reducing the health hazard from food allergy.     

Biogenic amines,histamine and label of dressed fried fish meat products in Taiwan

One hundred and four dressed fried fish meat products, including 44 packaged and 60 unpackaged, were purchased from supermarkets and retail outlets, respectively in Taiwan between September 2002 and March 2003. The levels of histamine and biogenic amines and labeling condition were determined. It was found that 9%, 11%, 2%, and 18% of the packaged products did not meet the labeling requirement of ingredient, expiry date, address and telephone information, and nutrition information, respectively. Although no sample exceeded histamine level of 500 ppm, all packaged products and 24 out of 60 unpackaged ones showed detectable amounts of histamine. Fourteen samples of packaged products and two samples of unpackaged ones had histamine above 50 ppm, with level ranged from 53 to 87 ppm and from 75 to 108 ppm, respectively. The biogenic amines content of packaged product was higher than unpackaged one with average level of 725 ± 252 ppm and 595 ± 181 ppm, respectively. The dressed fried fish meat products with histamine level above 50 ppm sold in Taiwan should be considered.     

Determination of histamine and biogenic amines in fish cubes (Tetrapturus angustirostris) implicated in a food-borne poisoning

An incident of food-borne poisoning causing illness in 347 victims due to ingestion of fried fish cubes occurred in June, 2007, in Kaohsiung city, southern Taiwan. A high-performance liquid chromatography (HPLC) was developed for determining nine biogenic amines in two suspected fish samples by dansylation with dansyl chloride. One sample has histamine content (52.3 mg/100 g) greater than the hazard action level of 50 mg/100 g. Given the allergy-like symptoms of the victims and the high histamine content in the suspected fried fish samples, this food-borne poisoning was strongly suspected to be due to histamine intoxication. In addition, two weak histamine-producing isolates were identified as Acinetobacter baumannii, by 16S rDNA sequencing with PCR amplification.     

The prevalence and serovar diversity of Salmonella in various food products in Estonia

In this work the prevalence and serovar diversity of Salmonella in various food products including non-thermally processed food and ready-to-eat (RTE) food in Estonia in 2008–2012 are summarized. The findings demonstrate that the overall prevalence of Salmonella in these food categories was low. A total of 260 (0.54%) of 47,927 food samples were found to be positive for Salmonella, the overall prevalence in non-thermally processed food was 0.81% (256/31,576) and in RTE products only 0.02% (4/16,351). Salmonella was most often isolated from raw eggs and products thereof (2.17%, 5/230), followed by raw meat products (0.95%, 207/21,723), RTE mayonnaises (0.90%, 2/221) and raw meat (0.89%, 38/4252). In the raw meat category, Salmonella was most frequently isolated from turkey meat (6.96%, 11 positive samples out of 158), broiler chicken meat (4.00%, 7/175) and from layer hen meat (2.22%, 11/496). Salmonella was isolated in lesser extent from meat preparations (1.91%, 82/4292), minced meat and mechanically separated meat products (0.97%, 100/10,344) and from raw sausages (0.35%, 25/7087).Altogether 24 different serovars were identified among the 260 Salmonella positive samples. Salmonella Typhimurium was the most frequent serovar (26.90% of the positive samples) and it was isolated most commonly in raw food products. The next most frequent serovars were Salmonella Derby (17.50%), Salmonella Enteritidis (8.37%) and Salmonella Newport (7.57%). The only serovars isolated from the Salmonella positive RTE food samples were Salmonella Infantis (two isolates) and S. Enteritidis (two isolates).     

A sandwich ELISA for the detection of fish and fish products

Fish is classified as one of the major allergenic foods. However, a reliable assay for detecting the presence of fish protein is not available. In this study, a sandwich enzyme-linked immunosorbent assay (sELISA) was developed using polyclonal antibodies raised against a 36 kDa thermal-stable fish muscle protein. The sELISA was able to detect both raw and cooked (100 °C, 8 min) fish samples of all 63 common species tested without any cross-reaction with non-fish samples. The assay can also detect fish products with different processing (salting, smoking and canning). The detection limit of the assay was 0.1 ppm for both raw and cooked fish (whiting, pollock and basa) in crab meat. The assay exhibited low intra- (CV ≤ 8.9%) and inter-assay variability (CV ≤ 9.3%). The rates of false-positive and false-negative were 0%. This fish-specific sELISA is, therefore, an effective assay for the detection of fish muscle protein in food for the protection of fish-allergic individuals.     

Use of food safety objectives to satisfy the intent of food safety law

Corporate food safety objectives and a HACCP based management system were used to resolve a simple, but very costly, conflict between the strict interpretation of food safety regulations and the commercial ability to serve safe food that fulfils the intent of the law. A case study will be presented in which rare roast beef was removed from the menu after health authorities found that the product was served at less than 60 °C, a violation of national regulations.A risk assessment and risk management strategy specific for serving rare roast beef was developed. The documentation clearly and scientifically demonstrates how physical processes for cooking, hot holding, service and cooling were validated to support the company's commitment to food safety and business excellence. Working instructions for each step of preparation and service of rare roast beef were validated. A specific HACCP plan was developed to manage the daily adherence to the working instructions. This HACCP plan is integrated into an overall systems approach to daily kitchen routines, so as not to place undue burdens on staff or management. Food safety objectives enable the company to communicate why the procedures to serve rare roast beef are safe. This rational approach to linking the explanation of procedures with safety is important for internal training, long-term program stability and external public relations.     

Effect of starter cultures on microbial ecosystem and biogenic amines in fermented sausage

The microbial ecology of fermented sausages inoculated with different starter cultures (Pediococcus pentosaceus + Staphylococcus xylosus, batch A; Lactobacillus farciminis + Staphylococcus saprophyticus, batch B) was studied by culture-dependent and independent methods. The concentration of biogenic amines, pH and a_w (water activity) were followed. The starter B can inhibit indigenous bacteria effectively judged by traditional microbiological method and PCR-DGGE fingerprint. There was no statistical difference in pH between batches A and B at 2 days when substantial amounts of BAs were produced, while the amounts of histamine, putrescine, cadaverine and tyramine in batch B was lower than in batch A significantly (P < 0.001). As a result, the starter cultures which can complete, grow well and inhibit amine-positive bacteria play an important role in reducing the production of BAs during ripening of fermented sausage.     

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.     

Assuring the safety of irradiated food

The way in which irradiation of meat and poultry is regulated in the US is discussed, together with guidelines for developing quality control programmes for irradiation within a hazard analysis and critical control point system, packaging considerations and materials, labelling requirements, and the importance of keeping international standards in mind when developing irradiation guidelines.     

Determination of aflatoxin levels in some dairy and food products which consumed in Ankara,Turkey

Two hundred and twenty-three samples of dairy products (49 samples of cheese, 94 samples of white cheese, 53 samples of Kashar cheese, and 27 samples of butter), 51 dehulled hazelnut and 40 cacao hazelnut cream, marketed in Ankara, Turkey during September 2002–September 2003, were analysed for aflatoxin M1 (AFM1), total aflatoxin and AFB1 by microtitre plate enzyme-linked immunosorband assay (ELISA). The incidence of AFM1 contamination in dairy products analysed was 90.58%. AFB1 contamination was detected in 43 (84.32%) of dehulled hazelnut samples (ranging from <1 to 10 ppb) and in 38 (95%) samples of cacao hazelnut cream (ranging from <1 to 13 ppb). Total aflatoxin contamination was determined in 47 (92.16%) of dehulled hazelnut samples and in 39 (97.5%) samples of cacao hazelnut cream.AFM1 levels in 19 (8.52%) of 223 dairy product samples were determined higher than maximum tolerable limit of the Turkish Food Codex, whereas total aflatoxin levels in only one of 51 dehulled hazelnut and one of 40 hazelnut cacao cream samples were exceeded the legal limit.Continuous surevillance programme may be warranted to monitor regularly the occurrence of aflatoxins in foods and foodstuffs which consumed by human.     

Occurrence of coagulase-positive Staphylococcus in various food products commercialized in Botucatu,SP, Brazil and detection of toxins from food and isolated strains

The aim of this work was to assess the microbiological quality of commercialized desserts, sandwiches and finger food in Botucatu, SP, for human consumption. A total of 172 food samples were analyzed for fecal coliforms and coagulase-positive Staphylococcus and 69 (40.1%) were in disagreement with the standards established by Decree No. 12 (Brazilian Food Sanitation Standard, 2001). Coagulase-positive Staphylococcus was isolated from 26 (15.1%) samples. Toxins were not isolated directly from foods but 27 (54%) coagulase-positive Staphylococcus strains were enterotoxigenic, and toxin type C was the most frequently detected. These results suggest that these products may act as an important vehicle of transmission for well-established pathogens.     

Inhibitory effects of garlic and other spices on biogenic amine production in Myeolchi-jeot,Korean salted and fermented anchovy product

This study was carried out to reduce biogenic amine contents in Myeolchi-jeot, Korean salted and fermented anchovy (Engraulis japonicus). The effects of a variety of spices including ginger, garlic, green onion, red pepper, clove and cinnamon, on biogenic amine production were determined by HPLC. The greatest inhibitory effect on biogenic amine production was observed in the culture treated by garlic extract. In the culture, the contents of putrescine, cadaverine, histamine, tyramine and spermidine were reduced by up to 11.2%, 18.4%, 11.7%, 30.9% and 17.4%, respectively, compared to control. The other spice extracts tested showed less or no effect in reducing biogenic amine contents. In addition, the extract of garlic showed the highest antimicrobial activity against the amine producers tested. The extract of garlic at a concentration of 5% (weight basis) was finally applied to the ripening of Myeolchi-jeot in situ, and then overall production of biogenic amines in Myeolchi-jeot was found to be reduced by up to 8.7%, compared to control. Consequently, it is expected that the findings of this study might be helpful for enhancing the safety of Myeolchi-jeot.     

Chinese consumers food purchasing behaviors and awareness of food safety

This study examines consumer food purchasing behavior and awareness of food safety in China. We surveyed a total of 1015 consumers in Nanjing and Beijing and the results showed that consumers with a lower level of education tend to be less concerned about certain food safety factors compared to those with a higher level of education. The respondents with higher food expenditures were also more concerned about food safety than those who spent less money on food. Women, families with children or elderly people were also more concerned. Consumers in the used sample preferred to buy food from a super-market; paid more attention to the expiration date on the food label, food color and the nutritional content of food products. Consumers had little knowledge of who was responsible for food safety in China; therefore educating consumers on who was responsible for food safety in China may help mitigate consumers’ concerns.     

Knowledge of food safety and food handling practices amongst food handlers in the Republic of Ireland

Food safety concerns have existed for a long time, as millions of people across the globe suffer from food borne disease every year. Contamination of food owing to limited knowledge of food safety practices primarily increases the risk of food borne illnesses. In the present study, quantitative research was carried out to gauge the level of food safety knowledge amongst people living in Ireland. A total of 1069 participants from all over the Republic of Ireland contributed to the survey (of which 821 were included in this research). Results showed that the residents of Ireland overall had an average level on knowledge of food safety practices (67.0% passing rate). They had an average level of knowledge in food storage (52.8% passing rate), usage and maintenance of the kitchen facilities (59.0% passing rate), and personal hygiene (61.0% passing rate). Conversely, they had a critically low level of knowledge in food handling (10.8% passing rate) and food poisoning (20.1% passing rate). The results of the present study also showed that, the level of knowledge of food safety practices varies amongst the residents based upon their gender, age, place of residence, education level, and marital status, while no significant difference in the knowledge level was observed based upon their per capita income. The study thus, highlights that there is scope for improvement for the residents to advance their knowledge of food safety practices. Therefore, it can be recommended that researchers, educators, food safety communicators, and the media can engage in educating the population, to help the residents advance their food safety knowledge to safer food practices.