Sushi Samples Research Articles

Occurrence and level of Listeria monocytogenes and Salmonella in sushi at retails in Greater Jakarta area, Indonesia

Sushi is ready-to-eat food consisting of cooked vinegared rice and raw fish. Since sushi does not undergo heat treatment, inadequate control in the production may lead to microbial contamination. This study aimed to determine the prevalence and level of Listeria monocytogenes and Salmonella contamination in sushi sold in Greater Jakarta (Jakarta, Bogor, Depok, Tangerang, and Bekasi) area, Indonesia using the MPN-PCR method. Samples of sushi (n = 120), consisting of nigiri (rice with raw fish on top) (n = 57) and maki (rice with raw fish inside) (n = 63), were obtained from retail outlets in Jabodetabek. The results showed that both sushi products were more frequently contaminated with L. monocytogenes (14.2%) than Salmonella (2.5%). The contamination levels for L. monocytogenes and Salmonella were 3-1100 and 3.6-11 MPN/g, respectively. The highest prevalence of L. monocytogenes was found in maki sold in supermarkets (66.7%) and nigiri in kiosks (22.2%). In addition, maki and nigiri from restaurants have the highest prevalence of Salmonella at 2.2 and 3.8%, respectively. These findings indicate that contamination of L. monocytogenes and Salmonella in sushi sold at retail in Jabodetabek may pose a health risk to consumers and more study is needed to determine the source of contamination along the processing of sushi.

Occurrence of Antibiotic-Resistant Bacteria in Fish and Seafood from Slovak Market.

The consumption of sushi or poke has grown globally. However, this type of dish often contains raw fish or seafood; therefore, it can pose a microbial risk for consumers. This study deals with the occurrence of total and antibiotic-resistant coliform bacteria and enterococci in fish and seafood as well as sushi and poke bought from Slovak retail (restaurants and fast food). Total coliforms have ranged in sushi, poke samples and samples of fish and seafood from cooling counters from 0.6 to 5.1 log CFU/g. Ampicillin resistance has been predominantly observed in all types of samples. Tetracycline resistance was detected in 16% of all tested samples and gentamicin resistance in 13%. Total enterococci has been detected in 74% of sushi samples, 100% of poke samples and 62% of samples obtained from supermarkets. The majority of enterococci were resistant to ampicillin. Vancomycin resistance was observed in five samples. Forty-eight resistant coliforms were identified mainly as Enterobacter spp. and Klebsiella spp. Antibiotic-resistant isolates were predominantly resistant to gentamicin, chloramphenicol and tetracycline. In 13% of resistant isolates was detected efflux pumps overproduction, and in four isolates was detected the tetA resistance gene. Our results point to poor hygiene in some establishments. The prevention of the antibiotic-resistant bacteria spread would be in better stewardship and improved monitoring of sanitation.

Microbiological safety and quality of ceviche, poke, and sushi dishes sold at retail outlets in Orange County, CA

Raw, ready-to-eat (RTE) seafood products, such as ceviche, poke, and sushi, have experienced growing demand globally; however, these products have the potential to be contaminated with foodborne pathogens. The objective of this study was to determine the prevalence of Escherichiacoli/coliforms, Salmonella, and Listeria in ceviche, poke, and sushi dishes sold at the retail level in Orange County, CA, USA. Additional organisms detected during testing were also considered in the results. A total of 105 raw, RTE samples of ceviche, poke, and sushi were collected from restaurants and grocery stores in Orange County, CA. Samples were tested for Salmonella and Listeria utilizing methods from the Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM). E. coli and total coliforms were enumerated utilizing 3 M Petrifilm plates. Overall, two samples (1.9%) were positive for generic E. coli, with a range of 5–35 CFU/g. Coliforms were detected in 85 samples (81%), with a range of 5–1710 CFU/g. The average coliform levels in ceviche samples (259 CFU/g) were significantly higher than the levels in sushi samples (95 CFU/g), according to a Kruskal-Wallis H test followed by the Dunn test (p < 0.05). The coliform levels in poke samples (196 CFU/g) were not significantly different from those in ceviche or sushi. All levels of E. coli and coliforms were considered acceptable or satisfactory/borderline according to standards for RTE seafood. None of the samples tested positive for Salmonella or Listeria monocytogenes; however, other microorganisms were detected in 17 samples, including Listeria spp., Proteus mirabilis, Providencia rettgeri, and Morganella morganii. The results of this study are novel in that they present data on the microbiological safety and quality of ceviche, poke, and sushi dishes sold at retail in the United States, as well as provide a comparison across the three categories of raw, RTE seafood.

Evaluasi Sistem Jaminan Keamanan Pangan di Restoran Multicabang PT XYZ Area Jakarta

Improper restaurant management causes potential food safety hazards which can lead to decline in public health. This study aims to evaluate food safety system at restaurant multisite PT XYZ area Jakarta to determine the knowledge of managers and knowledge, attitudes and practices of food handler about food safety, analyze level correlation between knowledge food handlers with attitudes and practices, correlate food safety knowledge restaurant managers with E. coli contamination and also observed general food safety implementation in restaurant. Data collection was by filling out questionnaires by 136 food handlers and 44 restaurant manager and observation of food safety in 44 restaurants. The results showed that restaurant managers had good knowledge of food safety and 63.6% had attended food safety training. Food handlers had good knowledge, attitudes, and practices (77.21, 84.56, 80.15%). Statistical analysis did not indicate a significant correlation between knowledge and attitudes. However, it was found that there is correlation between knowledge with practice and attitudes with practice. Observation result of restaurant food safety implementation showed that 93.8% had a good implementation. The knowledge of restaurant managers correlated positively with the implementation of restaurant food safety practices, but did not correlate with the presence of E.coli. The presence of E.coli did not indicate corelation with restaurant observation value. Testing E.coli at 44 restaurants showed that 9 of the salad samples and 3 of the sushi samples were detected by E.coli, while the ice coffee milk did not detect E. coli.

Use of DNA Barcoding to Identify Species of Raw Ready‐To‐Eat Seafood Products Sold in Orange County, CA

DNA barcoding is widely used to identify commercial fish species sold in the U.S and internationally. This method is based on DNA sequencing of a standardized region of DNA from a sample. Sequences can then be analyzed against the Barcode of Life Data system (BOLD) for species identification. Additional analysis of samples by a method called DNA mini‐barcoding can be used for samples that cannot be correctly identified to the species level by the traditional DNA barcoding method. While relatively high levels of seafood mislabeling have been reported for sushi dishes, few studies have investigated mislabeling of other raw, ready‐to‐eat (RTE) seafood such as poke and ceviche. The objective of this study was to evaluate the presence of species mislabeling in raw, RTE seafood products in Orange County, CA. DNA barcoding and mini‐barcoding were used to investigate 70 samples of sushi, ceviche, and poke collected from various locations in Orange County. All samples underwent DNA barcoding, followed by species identification using the BOLD database. Six samples underwent further analysis with mini‐barcoding. The FDA seafood list was used to identify common and acceptable market names. The results showed that 13 samples were substituted on the basis of species, and 20 samples did not have an acceptable market name. The overall mislabeling rate for all samples combined was 52.3% (33/63). These results indicate a need for greater scrutiny of labeling practices for raw, RTE seafood sold in Orange County, California.

Authentication of fish species served in conveyor-belt sushi restaurants in Taiwan using DNA barcoding

Fish fraud is a problem worldwide. Not only does it erode customer confidence, but it also jeopardizes public health. Typically, it is difficult to authenticate fish species identity based on morphological characters after food processing. Fortunately, DNA is relatively resistant to processing methods, and DNA barcoding has proven useful for species identification. Although fishery product mislabeling is recognized as an issue in Taiwan, a respective study on sushi has not yet been conducted. Here, we successfully DNA-barcoded 121 out of 122 sushi samples from eleven chain restaurants of the conveyor-belt type in Taiwan, revealing an overall mislabeling rate of ~17.36%. We found that capelin roe is commonly used to replace other fish roe, such as herring. Tuna, which is susceptible to fraud, was always correctly labeled. We also noted inconsistent usage of Chinese common names, conflict between Chinese and English names, and ambiguous usage of Japanese kanji in Chinese labels, all serving to confuse species identity. Moreover, spurious reference sequences in the BOLD database and the lack of a standard list of common names of fishes with their corresponding scientific name both impede investigations of fish substitution. We advocate that the responsible authorities establish a reliable barcoding database for molecular authentication of fishes, publish a respective standard for common and scientific names, and legislate for more comprehensive labeling regulations based on experience in other jurisdictions to facilitate mislabeling investigations and to deter food fraud. • A high successful rate in amplifying full-length DNA barcodes from sushi samples. • “Correctly” labeled items may not have matched customer expectations. • A reliable barcoding database is required. • A “Taiwanese Fish Names Standard” is appealed to be constructed. • A comprehensive labeling regulations is needed for food fraud investigations.

Pathogenicity and seasonal variation of Aeromonas hydrophila isolated from seafood and ready-to-eat sushi in South Korea

Aeromonas hydrophila is an emerging foodborne pathogen capable of causing human gastroenteritis, and the main reservoir is the aquatic environment. In this study, the prevalence and virulence of A. hydrophila in seafoods and ready-to-eat (RTE) sushi distributed in various conditions (refrigerated, dried, or frozen) or seasons was investigated. Strains were isolated from seafood (refrigerated or frozen oysters, sashimi, and processed fish; n = 333) and RTE sushi (n = 88) samples collected in South Korea and then genetically analyzed for gastroenteritis-related virulence genes (aer, ast, and alt). Raw oysters showed the highest prevalence of A. hydrophila (57.1%; 47/91) among all seafoods. Among the sashimi samples, flatfish sashimi (54.8%; 34/62) and salmon sushi (51.4%; 18/35) were the most prevalent. A. hydrophila was not detected in the oysters or anchovies distributed as either frozen or dried products. Seasonal investigations of sashimi and sushi showed that the summer prevalence of A. hydrophila with putative virulence genes was significantly lower in sashimi but highest in sushi. These results indicated that sushi could have been contaminated from several sources during the manufacturing or distribution processes. Significant correlations among the prevalence of putative virulence genes were confirmed, although no combination of genes presented a Phi correlation coefficient above 0.5 (0.26–0.43). To our knowledge, this is the first study to investigate the prevalence of A. hydrophila in various types of retail seafoods and RTE sushi in the East Asia region and then relate the prevalence to the distribution conditions of the samples. This study provides background information on the level of potential risk posed by A. hydrophila in retail seafoods and RTE sushi.

Dietary exposure to potentially toxic elements through sushi consumption in Catalonia, Spain

Although sushi is considered as a healthy food, it can also be a route of exposure to chemical contaminants such as potentially toxic trace elements. In this study, we analysed the concentration of Cd, I, Ni, Pb and total Hg, as well as iAs and MeHg in sushi samples. Iodine levels were higher in samples containing seaweed, while iAs concentrations were greater in rice-containing sushi. In turn, total Hg and MeHg were significantly higher in sushi samples with tuna. Health risks of sushi consumption were assessed for three population groups: children, adolescents and adults. Considering an average intake of 8 sushi pieces for adults and adolescents, and 3 sushi pieces for children, the estimated exposure to MeHg by adolescents exceeded the tolerable daily intake set by EFSA, while MeHg intake by children and adults was below, but close to that threshold. A relatively high daily exposure of Ni and Pb was also found, especially for adolescents. Since this study focused only on the consumption of sushi, the contribution of other food groups to the overall dietary exposure should not be disregarded. It might lead to an exposure to MeHg and other trace elements above the health-based guideline values.

Geographic Pattern of Sushi Product Misdescription in Italy-A Crosstalk between Citizen Science and DNA Barcoding.

The food safety of sushi and the health of consumers are currently of high concern for food safety agencies across the world due to the globally widespread consumption of these products. The microbiological and toxicological risks derived from the consumption of raw fish and seafood have been highlighted worldwide, while the practice of species substitution in sushi products has attracted the interest of researchers more than food safety agencies. In this study, samples of sushi were processed for species authentication using the Cytochrome Oxidase I (COI) gene as a DNA barcode. The approach of Citizen Science was used to obtain the sushi samples by involving people from eighteen different Italian cities (Northern, Central and Southern Italy). The results indicate that a considerable rate of species substitution exists with a percentage of misdescription ranging from 31.8% in Northern Italy to 40% in Central Italy. The species most affected by replacement was Thunnus thynnus followed by the flying fish roe substituted by eggs of Mallotus villosus. These results indicate that a standardization of fish market names should be realized at the international level and that the indication of the scientific names of species should be mandatory for all products of the seafood supply chain.

Microbiological Quality Assessment of Sashimi and Sushi Sold in the Federal District, Brazil

This study aimed to evaluate the microbiological quality of sashimi and sushi sold in the Federal District, Brazil. A total of 54 samples (27 sashimi and 27 sushi) were collected in 25 commercial establishments. Samples were tested for counts of mesophilic and psychrotrophic bacteria, determination of total and thermotolerant coliforms, Staphylococcus aureus counts, and presence of Salmonella. The results showed that 40.7% of sashimi (11/27) and 25.9% of sushi (7/27) samples were unfit for consumption according to Brazilian legislation. Salmonella (genetically confirmed by the invA gene’s presence) was present in 25.9% of the sashimi samples (7/27). Thermotolerant coliforms were positive in 92.5% of sashimi samples (25/27) and 74.0% of sushi samples (20/27), and one sashimi sample was unfit for consumption (≥ 2.0 log MPN g-1). S. aureus bacteria exceeded the acceptable limit of 3.0 log CFU g-1 in 14.9% of sashimi samples (4/27) and 25.9% of sushi samples (7/27). A high count of S. aureus bacteria in some sushi and sashimi samples indicates improper personal hygiene while processing these ready-to-eat foods. Salmonella spp. can occur by improper handling of these foods or by the contact of fish with waters contaminated with sewage. These results can pose a health risk to consumers and indicated the need to improve good hygienic practices in establishments selling sashimi and sushi in Federal District, Brazil.

Evaluation of Microbiological Quality in Fresh Sushi Samples

In this study, it is aimed to determine the microbiological quality of 60 different raw salmon finger sushi (maki rolls) samples randomly supplied from consumption points (sushi bar, sushi buffet, hotel, restaurant etc.) serving fresh sushi. The counts of Escherichia coli, coagulase positive Staphylococcus aureus, Vibrio paraheamolyticus and Salmonella spp. presence (+/-) were examined in these samples for the detection of hygienic quality and pathogenic microorganisms. Twenty-nine of 29/60 (48.3%) samples were found to be positive for these microorganisms. Salmonella spp. presence was detected in 2/60 samples (3.3%) while coagulase positive S. aureus was found in 10/60 samples (16.7%) with a highest level of 4.84 log CFU/g. E. coli was detected in 15/60 samples (25%), V. paraheamolyticus was determined in 13/60 samples (21.7%) with a level of 2.90 log CFU/g and 2.82 log CFU/g, respectively. Based on the current findings, it is considered that microorganisms determined in the samples pose a risk to public health, authorities should mandate to conduct routine inspections more frequently and businesses selling sushi should be included in the annual sampling plan. It will be beneficial for healthy sushi production that it should be paid attention to hygienic production during the all manufacturing, storage and service stages in the sushi production and points of sale and relevant personnel should be ensured to routinely receive necessary food safety training to minimize the risk of foodborne disease outbreaks.

Evaluation and Microanalysis of Parasitic and Bacterial Agents of Egyptian Fresh Sushi, Salmo salar.

The present study aimed to evaluate the quality of fresh sushi in Egypt. Fifty samples of sushi (Salmo salar) were collected from restaurants in Alexandria, Egypt. Paraffin, semi-thin and ultra-thin sections were used for parasitological analysis by light and transmission electron microscopy. Bacteria were isolated by the dilution plate and direct plate methods and identified by a Vitek system. Twenty (40%) of the total examined samples showed microsporidia and helminth metacercariae infections. Histochemical stains showed distinct pinkish-red pyriform microspores embedded in muscular tissue stained with Gram, periodic acid-Schiff (PAS), and Ziehl-Neelsen (ZN) stains. Semi-thin sections showed double membrane xenoma-inducing granulomas containing spores at different developmental stages. Empty sporophorous vesicles and free spores were observed in the electron microscopic images. A bacteriological assay showed forty samples (80%) contaminated with human pathogenic bacteria with the average total bacterial counts ranging from 32 to 526 CFU/g. Four species of human pathogenic bacteria were identified in the examined samples, namely Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, and Serratia plymuthica in 40, 38, 11, and 6 samples, respectively. These constitute the first record of fresh sushi product in Egypt and indicate the potential pathogenicity associated with raw seafood products.

First report ofEscherichia coliO157:H7 in ready‐to‐eat sushi

The aim of this study was to evaluate the microbiological quality of commercially prepared ready-to-eat (RTE) sushi by enumerating aerobic mesophilic bacteria (AMB) and thermotolerant coliforms (TC) and detecting Escherichia coli and Salmonella ssp. An isolate was identified as E. coli O157:H7 which was evaluated for its virulence and antimicrobial resistance profiling as well as its ability to form biofilms on stainless steel. There were four sampling events in seven establishments, totalling 28 pools of sushi samples. Mean AMB counts ranged between 5·2 and 7·7 log CFU per gram. The enumeration of TC varied between 2·1 and 2·7 log MPN per gram. Salmonella ssp. were not detected, and one sample was positive for E. coli and was identified as E. coli O157:H7. To the best of our knowledge, this is the first report of E. coli O157:H7 in sushi samples in the world literature. This isolate presented virulence genes stx1, stx2, eae and hlyA. It was also susceptible to 14 antimicrobials tested and had the ability to form biofilms on stainless steel. There is a need to improve the good hygiene practices adopted in establishments selling sushi in the city of Pelotas, Brazil. In addition, the isolated E. coli O157:H7 carries a range of important virulence genes being a potential risk to consumer health, as sushi is a RTE food. This isolate also presents biofilm formation ability, therefore, may trigger a constant source of contamination in the production line of this food. The increase in the consumption of sushi worldwide attracts attention regarding the microbiological point of view, since it is a ready-to-eat food. To our knowledge, this was the first time that E. coli O157:H7 was identified in sushi samples.

Mycotoxin Incidence in Some Fish Products: QuEChERS Methodology and Liquid Chromatography Linear Ion Trap Tandem Mass Spectrometry Approach.

The inclusion of vegetal raw materials in feed for fish farming has increased the risk of mycotoxin occurrence in feed, as well as in edible tissues from fish fed with contaminated feed, due to the carry-over to muscle portions. Therefore, the objective of this study was to evaluate the occurrence of 15 mycotoxins in processed fish products, which are commonly consumed, such as smoked salmon and trout, different types of sushi, and gula substitutes. A QuEChERS method was employed to perform the mycotoxin extraction from fish samples. For mycotoxin identification and quantitation, the selected technique was the liquid chromatography-tandem mass spectrometry linear ion trap (LC-MS/MS-LIT). Smoked fish and sushi samples results were negative regarding the presence of all 15 mycotoxins studied. In contrast, small amounts of fusarenon-X and enniatin B were found in gula substitute samples.

Growth of mesophilic Aeromonas salmonicida in an experimental model of nigiri sushi during cold storage

The genus Aeromonas includes human pathogenic bacteria frequently isolated from seafood, and the increased consumption of ready-to-eat seafood poses new food safety issues regarding the presence of potentially pathogenic Aeromonas spp. in stored products for raw consumption, such as retail sushi with a shelf life of up to three days. This study assessed 1) the growth kinetics of a mesophilic A. salmonicida strain during storage at 4 °C and 8 °C in a nigiri sushi model, and 2) the strain variability in growth at pH ranging from 3.5 to 10 for a subset of mesophilic Aeromonas strains previously isolated from sushi.Inoculated slices of raw salmon were compared with and without rice. A predictive model for A. hydrophila (ComBase Predictor) did not sufficiently predict growth of the tested strain under the intrinsic conditions of nigiri sushi or salmon at both temperatures. Refrigeration alone (4 °C) did not inhibit growth of A. salmonicida on salmon. Within the first 72 h, representing the typical shelf life of retail sushi products, we observed a 10-fold increase in the concentration of the inoculated strain (including a lag-phase of approximately 34 h). Contact with acidified rice, resulting in a pH drop in the salmon, was the reason for the decreased bacterial viability in the nigiri sushi samples. However, the effect of acidification decreased at 8 °C, resulting in a 2-fold increase in the growth rate and a reduced lag-phase compared to refrigeration.Variability in the ability to grow in different pH levels was observed between strains. The highest color formation rates, representing cellular respiration analyzed in a phenotypic microarray system, were observed between pH 5 and 8. A few strains, including the A. salmonicida strain applied in the nigiri sushi model, were able to grow at pH 4.5 (at optimal temperature).The results demonstrated that mesophilic Aeromonas spp. can represent a microbiological hazard in retail sushi products during cold storage. Rice acidification in combination with low storage temperature (≤4 °C) are prerequisites to prevent growth of potentially pathogenic Aeromonas species during the relatively short shelf life.

The effect of non-thermal plasma on the lipid oxidation and microbiological quality of sushi

Abstract The study examined the effect of non-thermal plasma (NTP) on the total viable count and lipid oxidation of two common sushi products: nigiri and hosomaki. Sushi samples were treated with NTP using a dielectric barrier discharge system with 70 and 80 kV of potential differences for 5 min. The samples were stored at 4 °C for 11 days and analysed for total aerobic count, moisture and protein content, TBA index and fatty acids composition. Although the effect of NTP on the total aerobic counts was not statistically significant, a tendency in log reduction could be observed, with 1–1.5 log cfu/g reduction. Moisture and protein content, as well as fatty acids composition of sushi was not affected by the treatment. The TBA index of treated samples increased significantly by 0.4–1.5 mg/kg, with hosomaki reaching higher TBA index than nigiri. Although NTP in the studied conditions can, to a limited degree, increase the microbiological quality of the sushi samples, it also increases the oxidation rate.

Heavy metal contamination, microbiological spoilage and biogenic amine content in sushi available on the Polish market.

The present study determined the heavy metal contamination (mercury, cadmium, lead, arsenic and nickel) of nori, restaurant-served sushi and ready-to-eat sushi meals available via retail chains. Moreover, both microbiological load and biogenic amine content in ready-to-eat sushi meals were analysed. All of the nori samples contained high levels of Cd (2.122 mg kg-1 ), Ni (0.715 mg kg-1 ), As (34.56 mg kg-1 ) and Pb (0.659 mg kg-1 ). The studied sushi samples contained high levels of Ni and Pb, reaching 0.194 and 0.142 mg kg-1 wet weight, respectively, being potentially hazardous to women during pregnancy and lactation and small children. None of the studied samples contained high levels of Hg. Overall, 37% of ready-to-eat sushi meals exceeded a microbiological load of 106 cfu g-1 . However, biogenic amine content in all of the samples was low, with a highest histamine content of 2.05 mg kg-1 . Sushi is not the source of high levels of biogenic amines even with high microbiological loads. Nevertheless, the high microbiological loads at the end of the shelf-life indicate that some processors might have problems with the distribution chain or implement a poor hygienic regime. Moreover as a result of possible risk associated with heavy metal contamination, the present study highlights the need to establish new regulations regarding the contamination of nori and sushi. © 2017 Society of Chemical Industry.

Microbiological and Physicochemical Qualities of Sushi and Sashimi from Japanese Restaurants in Brazil

Japanese cuisine is known for its nutritional and sensory quality. Sushi and sashimi are highly perishable and widely consumed foods in Brazil. The production and storage of these foods under appropriate conditions are critical factors in ensuring consumer safety. This study was carried out to evaluate the microbiological and physicochemical conditions of sushi and sashimi sold in Japanese restaurants as well as their handling conditions. Samples of sushi (36) and sashimi (35) and 112 swabs of food handlers were collected from 18 Japanese restaurants of the central region, Brazil. Temperature, pH and Total Volatile Nitrogen Bases (in sashimi) of food samples were determined. Thermotolerant coliforms, coagulase positive Staphylococcus, Vibrio parahaemolyticus, Bacillus cereus (in sushi) counts and the detection of Salmonella sp. were also performed. Staphylococcus aureus and Escherichia coli were investigated in the swabs samples. The average temperature of the food samples at all the restaurants was higher than the recommended value as well as 63.9% of the sushi and 54.3% of the sashimi samples had above recommended pH. All sashimi samples had content within legal limits of Total Volatile Nitrogen Bases. Four samples (5.6%) were positive for thermotolerant coliforms, and in three of them (4.2%), E. coli was isolated. High counts of Bacillus cereus were found in 22.2% of the sushi samples. Coagulase positive Staphylococcus, Vibrio parahaemolyticus, and Salmonella sp. were not found in the samples analysed. In 9.0% of the clinical samples, thermotolerant coliforms were detected and E. coli was found in 5.4% (n = 6) of them. Staphylococcus aureus was not detected on any food handler. The high storage temperature of food, the lack of heat treatment and the microbial contamination found may lead the present microorganisms to reach high counts until consumption, and therefore represent risk to consumers. Thus, effective prevention by supervisory bodies is essential.

Salt microspheres and potassium chloride usage for sodium reduction: Case study with sushi.

The aim of the study was to estimate possibilities of salt substitutes usage in the preparation of two sushi types (nigiri and maki) prepared with different seafood (salmon: Salmo salar, tuna: Thunnus albacares, and shrimp: Pleoticus muelleri). Potassium chloride (Mary samples), Soda-Lo (hollowed microsphere of regular salt crystals), and regular salt (sodium chloride) were used in the experiment. Sushi samples (n = 1960) were evaluated by 40 trained panelists who noticed that maki shrimp samples prepared with Mary salt had higher bitterness (21.48 ± 28.01) in comparison with 2% sodium chloride (7.91 ± 8.80). The saltiness was lower in nigiri tuna prepared with Mary (49.59 ± 17.47) than 2% sodium chloride (61.11 ± 15.75). The study clearly showed the possibility of lowering sodium content in sushi meal with the usage of salt substitutes, with emphasis that Soda-Lo should be considered as a better option due to the retention of sensory properties in sushi samples prepared with this salt substitute.

Risk estimation to human health caused by the mercury content of Sushi and Sashimi sold in Japanese restaurants in Brazil

ABSTRACTAlthough fish is a healthy alternative for meat, it can be a vehicle for mercury (Hg), including in its most toxic organic form, methylmercury (MeHg). The objective of the present study was to estimate the risk to human health caused by the consumption of sushi and sashimi as commercialized by Japanese food restaurants in the city of Campinas (SP, Brazil). The total Hg content was determined by atomic absorption spectrometry with thermal decomposition and amalgamation, and the MeHg content calculated considering that 90% of the total Hg is in the organic form. The health risk was estimated from the values for the provisional tolerable weekly ingestion (PTWI) by both adults and children. The mean concentrations for total Hg were: 147.99, 6.13, and 3.42 µg kg−1 in the tuna, kani, and salmon sushi samples, respectively, and 589.09, 85.09, and 11.38 µg kg−1 in the tuna, octopus and salmon sashimi samples, respectively. The tuna samples showed the highest Hg concentrations. One portion of tuna sashimi exceeded the PTWI value for MeHg established for children and adults. The estimate of risk for human health indicated that the level of toxicity depended on the type of fish and size of the portion consumed.