Concept: Japanese cuisine
Is the quality of sushi ruined by freezing raw fish and squid? A randomized double-blind trial with sensory evaluation using discrimination testing
- Clinical infectious diseases : an official publication of the Infectious Diseases Society of America
- Published over 4 years ago
Sushi is a traditional Japanese cuisine enjoyed worldwide. However, using raw fish to make sushi may pose risk of certain parasitic infections, such as anisakidosis, which is most reported in Japan. This risk of infection can be eliminated by freezing fish; however, Japanese people are hesitant to freeze fish because it is believed that freezing ruins sushi’s taste.
Both 3-monochloropropane-1,2-diol (3-MCPD) and acrylamide are contaminants found in heat-processed foods and their related products. A quantitative method was developed for the simultaneous determination of both contaminants in food by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). The analytes were purified and extracted by the matrix solid-phase dispersion extraction (MSPDE) technique with Extrelut NT. A coupled column (a 3m Innowax combined with a 30m DB-5ms) was developed to separate both compounds efficiently without derivatization. Triple quadrupole mass spectrometry in multiple reaction monitoring mode (MRM) was applied to suppress matrix interference and obtain good sensitivity in the determination of both analytes. The limit of detection (LOD) in the sample matrix was 5μg kg(-1) for 3-MCPD or acrylamide. The average recoveries for 3-MCPD and acrylamide in different food matrices were 90.5-107% and 81.9-95.7%, respectively, with the intraday relative standard deviations (RSDs) of 5.6-13.5% and 5.3-13.4%, respectively. The interday RSDs were 6.1-12.6% for 3-MCPD and were 5.0-12.8% for acrylamide. Both contaminants were found in samples of bread, fried chips, fried instant noodles, soy sauce, and instant noodle flavoring. Neither 3-MCPD nor acrylamide was detected in the samples of dairy products (solid or liquid samples) and non-fried instant noodles.
Dr. Kathleen Drew-Baker, “Mother of the Sea”, a Manchester scientist celebrated each year for half a century in Japan
- BioEssays : news and reviews in molecular, cellular and developmental biology
- Published almost 6 years ago
2013 marks the 50th annual Drew festival in Uto City, Japan, celebrating the work of University of Manchester botanist, Dr. Kathleen Drew-Baker. Her insight into the reproductive biology of algae was the key to efficient farming of the seaweed “nori” which is a familiar component of Japanese food.
A few years ago, Anisakis infection was almost unknown. Since the first observation in the Netherlands in 1960, several cases of gastrointestinal infections due to a zoonosis sustained by this nematode have been described in countries in which the consumption of raw or uncooked fish (e.g., marinated or salted) is common. Japan alone accounts for 90% of all cases of anisakiasis described in the literature because of the widespread use of raw fish in traditional Japanese cuisine, with sushi and sashimi. Nonetheless, other cases have been reported in Europe, North and South America, and Asia. In Italy, this zoonosis is rare and mostly transmitted by the ingestion of marinated anchovies in coastal areas, or fashion foods (sushi, sashimi, etc.) in inland areas. Once eaten, this parasite can cause an acute form of disease characterized by severe abdominal pain, and for this reason many patients receive the final diagnosis only on obtaining the surgical specimen. Since conservative medical treatment for acute anisakiasis relies on endoscopic removal of the nematode from the gastrointestinal wall if performed within 12h from the ingestion of contaminated fish, it should be compulsory to consider this parasitosis in the accident and emergency department. Here we describe two cases of infection by Anisakis simplex due to ingestion of marinated anchovies in a coastal area of the Tyrrhenian Sea and discuss the types and varieties of Anisakis infection in humans.
Risk estimation to human health caused by the mercury content of Sushi and Sashimi sold in Japanese restaurants in Brazil
- Journal of environmental science and health. Part. B, Pesticides, food contaminants, and agricultural wastes
- Published about 2 years ago
Although 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.
Estrogenic isoflavones were found, in the 1940s, to disrupt ewe reproduction and were identified in soy-consumers' urine in 1982. This led to controversy about their safety, often supported by current Asian diet measurements, but not by historical data. Traditional Asian recipes of soy were tested while assaying soy glycosilated isoflavones. As these compounds are water-soluble, their concentration is reduced by soaking. Pre-cooking or simmering time-dependently reduces the isoflavone:protein ratio in Tofu. Cooking soy-juice for 15 or 60min decreases the isoflavone:protein ratios in Tofu from 6.90 to 3.57 and 1.80, respectively (p<0.001). Traditional Tempeh contains only 18.07% of the original soybean isoflavones (p<0.001). Soy-juice isoflavones were reduced by ultra-filtration (6.54 vs 1.24 isoflavone:protein; p<0.001). Soy-protein and isoflavones are dissociated by water rinsing and prolonged cooking, but these have no equivalent in modern processes. As regards human health, a precise definition of the safety level of isoflavone intake requires additional studies.
Soy pulp, called “okara” in Japanese, is known as a by-product of the production of bean curd (tofu), and expected to contain a variety of biologically active substances derived from soybean. However, the biological activities of okara ingredients have not yet been fully understood, and the effectiveness of okara as a functional food seems necessary to be further evaluated. Then the effect of okara extract on angiotensin I-converting enzyme (ACE) activity was examined in vitro, and the extract was shown to cause the inhibition of ACE activity in a manner depending on its concentration. Kinetic analysis indicated that this enzyme inhibition was accompanied by an increase in the Km value without any change in Vmax. Further studies suggested that putative inhibitory substances contained in the extract might be heat stable and dialyzable, and recovered mostly in the peptide fraction obtained by a spin-column separation and a high performance liquid chromatography (HPLC) fractionation. Therefore, the extract was speculated to contain small-size peptides responsible for the inhibitory effect of okara extract on ACE activity, and could be expected to improve the hypertensive conditions by reducing the production of hypertensive peptide.
Salmon roe (SR) is commonly served daily in Russia and Japan. It is called salmon caviar, red caviar, rainbow trout roe, and ikra. SR is a component of famous traditional Japanese food, such as sushi rolls. As sushi has become widespread, so has SR consumption. SR is nutrition-rich, containing 32.6 g/100 g of protein and 15.6 g/100 g of fat. In Japan, SR is the fifth most common food allergen (1), and it can cause anaphylactic reactions in small children (2). Using sera from several SR-allergic patients, the beta component was identified as the main allergen (3, 4). This article is protected by copyright. All rights reserved.