Polycyclic aromatic hydrocarbons and halogenated persistent organic pollutants in canned fish and seafood products: smoked versus non-smoked products

In this study, levels of several groups of environmental contaminants represented by PAHs, PCBs, organochlorine pesticides and polybrominated diphenyl ethers were determined in various types of canned smoked and non-smoked fish and seafood products (54 samples) obtained from the Czech market. PAHs were detected in all of the studied samples, and at least one of the target halogenated persistent organic pollutants was present above the LOQ in 85% of the samples. The levels of PAHs, PCBs, organochlorine pesticides (mainly DDTs) and polybrominated diphenyl ethers found in the canned products varied in the range of 1.4–116?µg?kg^?1, 0.6–59.6?µg?kg^?1, 0.6–82.7?µg?kg^?1 and 0.1–2.1?µg?kg^?1 can content, respectively. Smoked sprats were the most contaminated fish product (n?=?12) in which the highest levels of both PAHs and persistent organic pollutants were found. In 67% of the samples of smoked sprats in oil, the level of benzo[a]pyrene exceeded the maximum level of 5?µg?kg^?1 established for smoked fish by European Union legislation. The distribution of target analytes between oil and fish fractions was also assessed. Significantly higher levels of PAHs were measured in the oil fraction.     

Furan in canned sardines and other fish

Thirty-seven different samples of canned sardines and other fish sold in the United Kingdom were analysed for their furan content using a validated automated headspace gas chromatography–mass spectrometry procedure. All 37 samples contained detectable furan, with an average level of 26 μg kg^?1. The maximum furan content was in canned fish containing tomato sauce, which had an average of 49 μg kg^?1 and in canned fish packed with lemon which had an average of 55 μg kg^?1. All fish in brine or in oil contained less than 20 μg kg^?1 furan. Furan levels recorded in fish packed in extra virgin olive oil were low with an average of 2 μg kg^?1.     

Incidence of Salmonella in fish and seafood

Field laboratories of the U.S. Food and Drug Administration collected and tested 11,312 import and 768 domestic seafood samples over a 9-year period (1990 to 1998) for the presence of Salmonella. The overall incidence of Salmonella was 7.2% for import and 1.3% for domestic seafood. Nearly 10% of import and 2.8% of domestic raw seafood were positive for Salmonella. The overall incidence of Salmonella in ready-to-eat seafood and shellfish eaten raw was 0.47% for domestic--one shucked oyster and one shark cartilage powder. The incidence in the 2,734 ready-to-eat import seafood was 2.6%--cooked shrimp, shellfish or fish paste, smoked fish, salted/dried fish, and caviar. The incidence in import shellfish consumed raw was 1% in oyster, 3.4% in clams, and 0% in mussels. The incidence in raw, import fish was 12.2%. Distribution of Salmonella in seafood on a regional basis indicated the incidence to be highest in central Pacific and Africa and lowest in Europe/Russia and North America (12% versus 1.6%). Data on a country basis indicated Vietnam to have the highest (30%) and Republic of Korea the lowest (0.7%). While the most frequent serotypes in import seafood were Salmonella Weltevreden (1st), Salmonella Senftenberg (2nd), Salmonella Lexington, and Salmonella Paratyphi-B (3rd, equal numbers for each serotype), the top 20 list included Salmonella enteritidis (5th), Salmonella Newport (6th), Salmonella Thompson (7th), Salmonella typhimurium (12th), and Salmonella anatum (13th), commonly involved in foodborne illness in the United States. Because the incidence in the present study is based on only a small fraction of the seafood imported into the United States, efforts should be directed toward implementation of hazard analysis and critical control points to reduce the incidence of Salmonella in seafood without relying on testing for Salmonella.     

Proximate composition, minerals and vitamins in selected canned vegetables

The proximate composition, and mineral and vitamin contents of canned white asparagus, whole peeled tomatoes, mushrooms and lentils were studied. The composition of the canned products did not vary during the harvest season, but calcium, sodium and potassium contents depended on the hardness of the water, added sodium chloride, and, in the case of lentils and mushrooms, the use of potassium metabisulfite or sulfur dioxide during soaking. After the canning process, the studied vegetables retained at least 89% protein, 65% carbohydrate and between 47% and 95% of the vitamins B₁, B₂, B₆ and C (dry weight basis, DW) versus the respective raw materials. The canned mushrooms and lentils did not lose crude fiber and whole peeled tomatoes and white asparagus retained 73% (DW) crude fiber.     

Organic and total lead in selected fresh and canned seafood products.

Various fresh and canned seafood products were examined for ionic alkyl lead, tetraalkyl lead and total lead. Dimethyl lead, diethyl lead, trimethyl lead and triethyl lead were extracted with diphenylthiocarbazone (dithizone) at pH 8 and 9 from enzymically hydrolysed samples. Butyl derivatives were formed by Grignard reaction prior to analysis by gas chromatography-atomic absorption spectrometry (GC-AAS). Tetraalkyl lead was extracted from the hydrolysates with hexane. Total lead was determined by reductive coprecipitation with palladium in the presence of ascorbic acid after nitric-perchloric digestion. Many of the samples contained low (less than 0.09-0.7 ng g-1) levels of trimethyl- and dimethyl lead. Triethyl lead was found at similar levels in several samples. Total lead levels were higher with values ranging from less than 5 ng g-1 to 2.9 micrograms g-1. Detection limits for the organolead and total lead methods were 0.07-0.2 and 3-19 ng Pb g-1 respectively.     

Biological value of protein from raw fish and canned fish

The authors evaluated the nutritive value of protein from 4 kinds of raw fish (herring, cod, mackerel, sprat) and its preserves. Experiments were made on rats fed the diets containing fish protein (8-10% of the total diet). Experiments included the determination of apparent and genuine digestibility, net protein utilization, and net dietary protein caloric value. Evidence was obtained that protein from fish and its preserves is characterized by high digestibility coefficient as compared with casein and egg powder. The highest net protein utilization was noted in animal groups fed the diet containing protein from raw fish. Protein assimilability from fish preserves was on the average 15% lower than that from raw fish.     

Quantitative analysis of water-soluble vitamins by ATR-FTIR spectroscopy

HPLC and microbiology are the methods traditionally employed to control the vitamin content in food mixtures. However, considerations of cost, time of analysis per sample and complexities involved in the technique have hampered the acceptance of those methods for raw materials analysis. Fourier Transform Infrared (FTIR) spectroscopy has substantial potential as a quantitative quality control tool for the food industry. FTIR analysis methods are convenient, rapid, accurate, and in conjunction with Attenuated Total Reflectance (ATR) technology, simplify sample handling. The advantage of choosing FTIR as a quantitative technique lies in its ability to readily carry out multicomponent analysis in association with software such as Partial Least Squares (PLS) regression. Results presented here were obtained from water-soluble vitamins (B1, B2, B6 and Niacin) mixtures diluted into a glucose matrix without any chemical extraction.     

Challenges in the identification of species of canned fish

The identification of fish species becomes a problem when the usual identifying characteristics are removed on processing and only a portion of flesh is available. When the flesh is raw or cooked under normal conditions, the species is readily established by electrophoresis of the muscle proteins. The procedure cannot be used for heat-sterilised canned fish as the proteins are severely denatured. DNA is also degraded but techniques are now available for targeting and amplifying species-specific fragments. The amplified products can then be analysed by a range of techniques some of which are suitable for food control laboratories.     

Occurrence of histamine in canned tuna fish from Iran

Histamine fish poisoning is a significant public health and safety concern and also a trade issue. Histamine was investigated in canned tuna fish in Qazvin province from Iran by ELISA method. Histamine was detected in 29.37 % canned tuna fish samples. The overall mean level of histamine was 8.59 ± 14.24 ppm and the concentration was between 2.51 and 74.56 ppm. Except four samples (2.50 %) of 47 positive canned tuna fish samples, histamine content of other positive samples was in compliance with Food and Drug Administration (FDA) legislation (lower than 50 ppm). Most canned tuna fish contain histamine with high mean value was produced in summer (52.50 %) and spring (47.50 %) seasons, the mean levels of histamine were 6.30 and 12.62 ppm in these positive samples, respectively. The results of this study indicate that the most canned tuna fish produced in Qazvin province of Iran has histamine levels lower than the allowable limit suggested by FDA. Further studies should be carried out to investigate the presence of this toxin and other biogenic amines in different fish and sea food products.     

鲟龙鱼头罐头加工

研究了鲟龙鱼头罐头的加工技术,分析生骨与熟骨的营养成分差异,解决鱼骨软化关键技术,运用质构仪分析熟制过程中软骨硬度、凝聚性、弹性、胶黏性及咀嚼特性,运用正交实验筛选调味配方,研究罐头贮藏特性。实验结果表明:调味料的最佳配方为(100 m L水中的添加量):酸菜60 g、食盐2.5 g、味精0.4 g、白醋1.0m L、胡椒粉0.4 g、白酒5.0 m L、生姜粉0.3 g、红辣椒10 g、植物油4 g,在115℃条件下高压处理15 min,产品能达到商业无菌要求,骨质软化程度适中,其各项微生物指标均符合国家指标规定的食品卫生标准。     

Determination of trace metals in canned fish marketed in Turkey

The levels of trace metals of canned fish samples collected from markets in Turkey were determined by flame and graphite furnace atomic absorption spectrometry after microwave digestion. The accuracy of the method was corrected by standard reference material (NRCC-DORM-2 Dogfish Muscle). The contents of investigated trace metals in canned fish samples were found to be in the range 1.10–2.50 μg/g for copper, 7.57–34.4 μg/g for zinc, 0.90–2.50 μg/g for manganese, 10.2–30.3 μg/g for iron, 0.96–3.64 μg/g for selenium, 0.45–1.50 μg/g for aluminium, 0.97–1.70 μg/g for chromium, 0.42–0.85 μg/g for nickel, 0.09–0.40 μg/g for lead and 0.06–0.25 μg/g for cadmium. The results were compared with the literature values.     

Dietetic canned food using ocean fish and plant components

The results of the creating canned ground goods of a new kind are described in this article. The main character references of food value of hake and the canned ground foods based on it. It has been established that the new products of safety. Clinical tests have been showed the efficiency of including these canned goods in the menu of fat patients, also with heavy obesity. Dietetic canned ground foods on the base of oceanic fishes with plant additives.     

Mercury,cadmium and lead content of canned tuna fish

Mercury levels in canned tuna fish were determined by cold vapour atomic absorption spectrophotometry while cadmium and lead levels were determined by flame atomic absorption spectrophotometry. The metal contents in the samples, expressed in μg g⁻¹ wet weight, varied from 0.20 to 0.66 with an average value of 0.29 for mercury, from 0.09 to 0.32 with an average value of 0.18 for cadmium and from 0.18 to 0.40 with an average value of 0.28 for lead. The results of this study indicate that tuna fish from the Mediterranean coast of Libya have concentrations well below the permissible levels for these toxic metals. Their contribution to the body burden can therefore be considered negligible.     

Quantification of water-soluble vitamins in milk-based infant formulae using biosensor-based assays

Vitamin analysis is essential for quality control and development of functional foods. In this study, a biosensor-based technology developed by Biacore AB was evaluated for analysis of water-soluble vitamins B₂, B₁₂, folic acid, biotin, and pantothenic acid used to supplement infant formula samples. Performance parameters such as accuracy, repeatability and recovery for the five vitamins were studied. The repeatability was measured in terms of relative standard deviation (RSD) and HORRAT_r value. The RSD for all vitamins was below 2% and the values of HORRAT_r were 0.16, 0.10, 0.15, 0.11 and 0.22, for B₂, B₁₂, folic acid, biotin, and pantothenic acid, respectively. The recovery of vitamins ranged from 94.7% to 109.1%. Linear analyses indicated that the square of the correlation coefficient (R²) for B₂, B₁₂, folic acid, biotin, and pantothenic acid were 0.993, 0.997, 0.993, 0.993 and 0.995, respectively. The results showed that the biosensor-based vitamin analysis technology is a sensitive, reliable and realistic alternative to other methods.     

Determination of water-soluble vitamins in soft drinks and vitamin supplements using capillary electrophoresis

A method for the determination of six water-soluble vitamins based on capillary electrophoresis (CE) operated in micellar mode was developed. Thiamine hydrochloride (vitamin B1), riboflavin (vitamin B2), pyridoxine hydrochloride (vitamin B6), pantothenic acid (vitamin B5), nicotinamide (vitamin B3), and cobalamin (Vitamin B12) could be separated in a single run. All CE parameters such as buffer composition and operation temperature were optimized in order to achieve better separation. Relative standard deviations (RSDs) of the described method ranged from 1.08 to 3.68% (intra-day precision) and 1.26 to 3.35% (inter-day precision). The method was then used for measuring various soft drinks and vitamin supplements directly without any step of sample cleanup. The determination of niacin was successful for all samples tested, reaching recoveries near 100%. Riboflavin and pyridoxine were quantified successfully in some but not all samples. Therefore, an evaluation on a case-by-case basis is mandatory. When applicable, this method provides a fast, accurate, simple, and inexpensive way to quantify selected vitamins, and is therefore well suited for routine analysis in soft drink industry.     

Monitoring of bisphenol-A-diglycidyl-ether (BADGE) in canned fish in oil

A survey at the European level was initiated on the quantification of bisphenol-A-diglycidyl-ether (BADGE) in canned fish in oil in order to assess the exposure of BADGE. A total of 382 canned fish samples were collected from all 15 Member States and Switzerland and analysed for BADGE in fish. The fish was extracted first with hexane and reextracted with acetonitrile, followed by a membrane filtration and reverse phase HPLC analysis with fluorescence detection. The analysis of the fish showed that about 3% of the samples contained BADGE at a level above 1mg/kg. The samples exceeding the limit by a larger margin were mostly from anchovy cans and cans manufactured in 1991-1995.     

Polychlorinated biphenyls in fresh and canned fish from the Central Adriatic.

By using the GLC method, levels of polychlorinated biphenyls (PCBs) were determined in fresh and canned fish during the 1984-88 period. Forty-six samples of fish caught in the Central Adriatic's littoral, 11 of which in a control, non-industrialized area, and 35 in an urbanized area strongly affected by industry, were collected. Also, 101 samples of canned fish were tested for PCBs. The average PCB values were 0.059 mg kg-1 and 0.287 mg kg-1 in control and polluted areas, respectively; the mean value in canned fish was 0.194 mg kg-1. Although the levels of PCBs in control and industrialized areas were found to differ, the difference was not significant statistically.     

Survey of methylmercury in fish and seafood from the southwestern German market

Mercury is an environmental contaminant and may occur as methylmercury in marine organisms. Methylmercury is considered as having higher toxicity than the inorganic form; therefore, it is important to differentiate the mercury species in order to evaluate the potential risk for seafood consumers. In the largest study of the German market to date, 536 marine foods from the state of Baden-Württemberg (southwestern Germany) were analyzed using gas chromatography with atomic emission detection. Methylmercury was found at levels ranging from non-detectable (below 6 μg/kg) up to 567 μg/kg. The average, median, 90th, 95th, and 99th percentile contents were 38, 22, 78, 117, and 316 μg/kg, respectively. The average methylmercury proportion of total mercury was 70%. Based on a daily total fish and seafood consumption of 30 g according to the German National Nutrition Survey II, the methylmercury exposure was estimated to range between 5 μg/week (median) and 67 μg/week (99th percentile), which was below the provisional tolerable weekly intake (PTWI) established by the Joint FAO/WHO Expert Committee on Food Additives. The risk of methylmercury for the German fish consumer was judged to be rather low, being restricted to the unlikely worst-case scenario of daily consumption of highly contaminated fish, which could exceed the PTWI. In conclusion, the previous opinions that the benefits of the moderate fish consumption appear to outweigh the risks associated with methylmercury exposure were confirmed by our survey.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

婴幼儿青豆鱼泥罐头的研制

研究了婴幼儿青豆鱼泥罐头的基本配方和加工工艺。通过感官评定及数学分析 ,得到青豆鱼泥罐头的基本配方为 :鱼泥 70 % ,米粉 2 0 % ,青豆 1 0 %。对按最佳配方生产的产品进行感官、理化及微生物检测 ,同时对产品进行保温贮藏试验 ,结果表明 ,按照该配方该工艺生产的青豆鱼泥罐头符合自定的质量标准 ,贮藏期间没有质量变化。