Showing papers in "Deutsche Lebensmittel-rundschau in 1998"

High selenium levels in edible albatrellus mushrooms

Abstract: A survey of 36 samples of terrestrial polypores, representing 12 species (6 belonging to the genus Albatrellus) were analysed for the trace element selenium using instrumental neutron activation, hydride generation atomic absorption spectrometry and fluorimetric methods. High concentrations of selenium, up to 367 mg/kg dry weight, were measured in Albatrellus pes-caprae, a popular edible mushroom in Italy, which is almost forgotten elsewhere in Europe. Albatrellus ellisii, a related edible species from the Pacific Northwest and California was found to concentrate similarly high levels. Both mushrooms also contained unusually high amounts of iron (up to 4360 mg/kg dry weight). Other Albatrellus, Boletopsis and Grifola species only had moderate to low selenium levels. The significance of these findings and the possible toxic action upon consumption of these mushrooms is briefly discussed. It is pointed out that hyperaccumulating Albatrellus present an unique material for investigating the nature of the selenium compounds present.

The human safety of the polycyclic musks AHTN and HHCB in fragrances : A review

Abstract: Reports of the polycyclic musks AHTN and HHCB in the environment have prompted a review of the safety of these important fragrance ingredients. Studies have been conducted on the acute and subchronic toxicity as well as for irritation and sensitization potential. A battery of genotoxicity studies has also been conducted. These materials are not skin irritants and show no potential for sensitization in human and animal screening studies. A combination of low systemic toxicity from subchronic studies and the total lack of genotoxicity indicates no potential for long term effects. Margins of safety based on the no-adverse-effect levels from subchronic studies are sufficient to conclude that direct exposure from the use of AHTN and HHCB in fragrances or indirect exposure form their presence in the environment pose no significant risk to human health. The envirommental risk assessment of AHTN and HHCB is the subject of a separate review.

Untersuchung von Phthalaten in Baby-Nahrung

Abstract: 22 samples of baby-milk, baby-food, mother's milk and cow's milk were analysed for their content of phthalates. After separating the fat by gel permeation chromatography the esters of the phthalic acid were separated by gas chromatography and identified and quantified by mass spectrometry. As internal standards Deuterium-labelled dibutyl- and dioctylphthalate were added. Analysing for 10 different phthalates only DBP and DEHP were found in the samples with maximum-concentrations till 50 resp. 200 μg/kg with a detection-limit of 10 μg/kg food. The relatively narrow range of the measured values point to the ubiquitous presence of these two components.

DNA-Extraktionsmethode für den Nachweis gentechnisch veränderter Soja in Sojalecithin

Abstract: Lecithins derived from soybeans can be found in a broad spectrum of different types of food, ranging from bakery products to antioxidants, stabilizer and emulsifiers. Soya lecithins consist not only of phosphatidylcholine but also of e.g. neutral fats, glycolipids and fragments of the soybean DNA. In 1996 approximately 2% of all US soybeans were of transgenic origin (the so called Glyphosate resistant Roundup Ready Soybean). For surveillance the Novel Food legislation as well as for regards of consumer informations a reliable scientific test to prove a genetically modified organism origin become more important. To respond to this situations we have developed a DNA extraction method for the isolation of small amounts of soybean DNA from soya lecithin. The DNA extraction method was tested in four laboratories with six different solid and liquid lecithins. The presence of soya DNA was determined with a primer pair yielding a fragment amplified from the soya lectin gene. Transgenic soya was determined with a primer pair specific for the Roundup ready soybean. In all four laboratories soybean specific DNA was extractable from all samples using the described extraction method.

Trace elements in wine from Croatia

Abstract: The amounts of Fe, Cu, Mn, Zn and Cr in twenty wines produced in different regions of Croatia were determined by means of atomic spectrometry. There were an average of 5.91 mg Fell (0.62-11.13 mg/l), 0.41 mg Cu/l (0.09-0.93 mg/l), 2.09 mg Mn/l (0.73-4.23 mg/l), 0.71 mg Zn/l (0.23-1,70 mg/l) and 33 μg Cr/l (12-75 μg/l). The average wine consumption in Croatia (0.095 l/day/person) contributed to dietary intake an additional intake of an average of 0.56 mg Fe, 0.04 mg Cu, 0.20 mg Mn, 0.07 mg Zn and 3 μg Cr, respectively. In regard to the described results' the wines from Croatia could be considered sanitarily safe and good additional source of investigated essential trace elements.

The safety of nitromusks in fragrances : A review

Abstract: Five nitroaromatic compounds, known as the nitromusks, are or have been used as fragrance ingredients. The safety of these materials has been studied for over 20 years. Studies have been conducted on the acute and subchronic toxicity as well as for irritation, sensitization and photosensitization potential. A battery of genotoxicity studies has also been conducted. One, musk xylene, has been the subject of a carcinogenicity bioassay. In addition, considerable dermal absorption, pharmacokinetic and mechanism studies have been undertaken. Most of this effort was undertaken by the Research Institute for Fragrance Materials (RIFM) as a result of the concern over the type of chemical structure and the considerable exposure through use in fragrances. In recent years, concern raised by the finding of these materials in the surface water, fish and human fat and milk samples have prompted further studies and this review. One of these substances, musk ambrette, has been shown to cause neurotoxicity and testicular atrophy in rats and photosensitization in humans. Thus, this material is no longer used in fragrances. Another, musk xylene, has been shown to cause hepatocarcinogenicity in B6C3F1 mice, however mechanistic studies have shown that this is not relevant to human health. Musk xylene and the other nitromusks, musk ketone, musk tibetene and moskene are not skin irritants, sensitizers or photosensitizers. They have also shown no potential for reproductive effects. Margins of safety based on the no-adverse-effect levels from subchronic studies are sufficient to conclude that direct exposure from the use of these materials in fragrances or indirect exposure from their presence in the environment pose no significant risk to human health. Their environmental risk assessment is the subject of a separate review.

Polyphenolanalytik von Fruchtsäften und Weinen mittels HPLC/UV/ECD an einer fluorierten RP-Phase

Abstract: A HPLC method for the analysis of fruit juice and wine polyphenols was developed. Compared to published methods based on RP 18-phase the separation of the polyphenols, especially for the flavonols and dihydrochalcons, could be improved by applying a new fluorinated RP-phase. An increase in sensitivity could be achieved by using electrochemical detection. A further advantage of the method is the possibility of the simultaneous analysis of anthocyanins and other polyphenols.

Production of bifidus Kariesh cheese

Abstract: Bifidobacterium bifidum were grown in different whey, permeate and milk-based media. Supplementation of these media with 0.5% (w/v) yeast extract exhibited higher population of bifidobacteria than soy extract, cystein, lysine and ascorbic acid. However, soy extract enhanced growth of B. bifidum in milk. The treatment of skim milk with β-galactosidase (7 μ/ml) stimulated growth of bifidobacteria specially when yeast extract and soy extract was supplemented to the milk in the same time. Kariesh bifidus cheese was successfully produced with high population of B. bifidum reached more than 3 x 10 10 cell/g after 5 days of storage at 7°C±1. By the end of storage period (10 days) the viable count was decreased to 3 x 10 8 cell/g but still more than the recommended population (10 6 cell/g) in such cases. Kariesh cheese was acceptable when organoleptically evaluated and gained higher scores than kariesh cheese prepared using yoghurt starter.

Aluminium content of some croatian wines

Abstract: The aluminium (Al) in different brands of white and red Croatian wines was measured, by the Zeeman graphite furnace atomic absorption spectrophotometry (ZGFAAS) method. The results show that white wines have a slightly higher mean Al concentration (2.82 mg Al/l) than red wines (2.51 mg Al/l). The extensive use of bentonite in the fining of white wines may be a main factor contributing to the observed higher mean Al concentration in white wines. The mean Al concentration of all wine samples investigated was 2.69 mg Al/l. This Al concentration is significantly below the tolerable Al content in Croatian wines (10 mg Al/l), established by Croatian Ministry of Agriculture. The evaluated daily intake of Al (1.345 mg Al/day) possible throught the consumption of wines could be a significant source of dietary Al intake, in comparison to the others beverage contribution. However, in relation to the establishedtolerable daily dietary Al intake of an adult person (60 mg Al/day), the contribution from wines is very low (practically negligible). Thus, it appears that the Al intake from wines should not be a cause for concern with regard to Al toxicity for the human body.

Untersuchung von Lebensmitteln auf Fumonisine

Abstract: In an investigation and research project of the Ministery of Environment of Baden-Wurttemberg the Chemische Landesuntersuchungsanstalt Sigmaringen inspected food and food products on contamination for fumonisins B 1 , B 2 und B 3 . The project fumonisins in food intended to reflect the contamination by testing food and food products being on the german market. The analyses were carried out with HPLC and fluorescence detection after using ion-exchance cartridges (SAX) or immunoaffinity columns (IAC) as a sample clean-up. The results of the investigations of this project were discussed.

Verfälschung von Arganöl (Argania spinosa/L./Skeel)

Abstract: The fatty acid spectrum of two oils from the seeds of Argania spinosa (L.) Skeel - argan, ardjan oil or Morocco olive oil - (Sapotaceae family) were analyzed by gaschromatography. The following fatty acids are contained in the argan oil (wt/%): oleic (42.7), linoleic (34.8), palmitic (12.5), stearic (4.5), and linolenic (3.5) as main constituents. This results are corresponded with the results of other autors. Characteristic are the high linoleic acid and the low oleic acid content as comparison with true sweet oil. The iodine number to Kaufmann of argan oil to be 107.6. The second examinated argan oil a different of the linoleic acid content behaviour 51.4%, of oleic acid 22.9%, and the linolenic acid 8.8%. The iodine number conducted 130.4. This argan oil is respected as falsificated.

Nitrat- und Nitritgehalte im essbaren Anteil von Fischen, Krebsen und Weichtieren

Abstract: The suitability of the official German method for colorimetric determination of nitrite and nitrate in sausages after enzymatic reduction of nitrate according to 35 LMBG 08.00 14 L was tested for fish and crustaceans. Some modification were necessary to allow an undisturbed determination of nitrite and nitrate in the fish matrix. Due to the low nitrate content in the edible part of marine fishes, the sample amount was set to 20 g and the precipitants Carrez I and II were increased, respectively. Samples should be analysed immediately after homogeneting to avoid a reduction of nitrate to nitrite catalysed by the fish matrix. Recovery experiments yielded a good recovery of 97% for 5 mg KNO3/kg cod (CV = 9.4%), applying the modified method. The edible part of 27 different fish and crustacean species and squid were analysed for residual nitrate and nitrite. Low concentrations of less than 3 mg KNO 3 /kg edible part were found in most of the marine fish samples, but some elevated levels were measured in farmed fresh water prawns. Nitrite was detected in none of the sample.

Nachweis und Bestimmung von Aprikosenkernbestandteilen in Marzipan mittels Isoelektrischer Fokussierung und einem molekularbiologischen Verfahren

Abstract: For the detection and determination of apricot kernels in marzipan raw materials and marzipan products two different and independent test methods were developed. By the isoelectric focusing in immobilized pH gradient it is possible to detect and characterize a specific protein, which is not detectable in almonds and marzipan, respectively. For the better solubility of the proteins the electropheretic determination was adapted with urea. The isoelectric point of the apricot protein is ca. 5.7 and the molecular weight ca. 17 000 Dalton. The isolectric focusing allows the qualitative und quantitative detection and determination of apricot kernels in marzipan. The detection and the determination limit is 0.2 and 0.7 g per 100 g marzipan, respectively. The second procedure describes a molecular biological test. The basic of it is the determination of an apricot kernel DNA fragment after amplification and description in an agarose gel. The base length of the DNA-segment is about 350. The method is high specific, the detection limit is about 0,5 g per 100 g marzipan. The description of the protein and the DNA segment is independent of the manufacturing and also of the country of origin. Both methods showed no false positive and no false negative results. By using both procedures it is possible to find out additions of apricot kernels in marzipan.

Klassifizierung von Darjeeling-Tee mittels multivariater Datenanalyse

Abstract: The knowledge about the provenience of a black tea is of great importance for quality assessment. For food control objective methods are necessary to enable checking the provenience of a black tea. On the first view the flavonol glycoside patterns of 45 black teas from different proveniences do not give any hints on the feasibility of classification or on characteristic parameters for certain proveniences. The use of multivariate methods of data analysis gives evidence for the 45 teas examined that: - differentiation of Darjeeling teas and other black teas is undoubtedly possible, -the criteria Q-rut and Q-rdg can be used for the identification of Darjeeling teas, - a fast modelling is possible by use of neuronal networks. To validate the results different methods of multivariate data analysis have been used. The model derived is correct within the 45 black teas and has a certain stability as shown throughout testing using neuronal networks. The model may be broadend by adding data of further tea proveniences or further data of proveniences enclosed already, leading to more generality and enhanced reality. This paper shall encourage to evaluate more dimensional data using matching tools of multivariate data analysis to receive a lot more information and solve similar problems.

Möglichkeiten und grenzen für den einsatz der polymerase-kettenreaktion (PCR) zum nachweis und zur typisierung lebensmittelhygienisch relevanter bakterien

Abstract: A brief cultural enrichment, followed by physical separation of the organisms from the culture and subsequent PCR using specific primers is a promising alternative to the conventional detection methods of pathogenic bacteria in foods. With limited workload, the method may provide confirmed results within 24 hours without the necessity to routinely isolate pure cultures. Use of PCR without prior cultural enrichment is of interest in the detection of bacteria that are difficult to cultivate, and of nonculturable or nonviable forms. However, for wider application in laboratories of food microbiology, the sensitivity of the latter method is unsatisfactory. Moreover, the time and effort required to concentrate and purify DNA from the samples makes it difficult to obtain the result within one working day. The PCR is an important tool to detect specific genes (especially, virulence genes) in pure cultures. Moreover, PCR-based typing methods have advantages (easily accessible reagents, few if any untypable strains) over typing methods based on phenotypic properties, and may thus assist in tracing back hygienically relevant organisms through the production chain. However, the reproducibility of electrophoretic patterns is a problem, particularly with the RAPD method. The methods described differ in their discriminatory power and the choice of a typing method (be it PCR-based or conventional) is difficult because it must be based on the degree of genetic homogeneity and stability of the species or subspecies to be typed.

Degradation of chlorophyll in model preparations

Abstract: When chlorophyll was dark-stored in coconut butter and the semisynthetic triacylglycerol Miglyol the samples were more stable than the mixture with sunflower oil. Light exposed chlorophyll (3.000 lux) was more stable in sunflower oil. Co-extracted plant constituents apparently decreased the stability of chlorophyll in the coconut butter model. An addition of α-tocopherol up to levels of 630 mg kg -1 improved the storability of crude chlorophyll preparations and of light exposed mixtures with coconut butter. The synergistic activity of lecithins (600 mg kg -1 ) correlated with their contents of phosphatidyl choline and yielded coconut butter/chlorophyll mixtures with a half life time of 24 days (3.000 lux 40°C) as compared to <20 hours for the non-supplemented chlorophyll/ coconut butter mixture.

Fumonisin-Konzentrationen in diversen Maisprodukten im Raume Karlsruhe und Rheinland-Pfalz in den Jahren 1993-1996

Abstract: The analysis of 38 sweet corn samples of the 1993 and 1994 crops yielded only 29% fumonisin positive results, with a maximum value of 193 ng/g. The 66 corn products of the 1994-95 crops were very differnt. While all 14 lots of one single producer showed FB 1 -concentrations between 127 and 9818 ng/g, the remaining products contained in 33% of the cases amounts between 6 and 453 ng/g. The result of the 1996 crop yielded in 17 samples, with one exception, only concentrations up to 43 ng FB 1 /g.

Determination of phenolic antioxidants in foods. Results of collaborative studies of the AIIBP-working group antioxidants

Abstract: Standardisation of a method for the determination of phenolic antioxidants in oils, fats and dry foods e.g. dry soup powders ist described. In a first collaborative study antioxidants were extracted with methanol. HPLC determination was performed according to IUPAC method 2.642. Experience showed that inference from co-extracted food components limited this method. Another HPLC method, developed for determination of ascorbyl palmitate, using a mobile phase containing a potassium dihydrogen phosphate buffer and water/methanol was investigated. In this alternative method most co-extracted components left the column very quickly giving isolated antioxidant signals. Although the number of participants in the collaborative studies was wather low, results showed that the method not only allows to determine of phenolic antioxidants in the foods within the permitted limits, but also to detect the use of fats stabilised with antioxidants in food preparation. The two collaborative studies showed that satisfactory results can only be obtained when participants have sufficient experience with the analytical technique applied.

Die Mahonie (Mahonia aquifolium/Pursh/Nutt.), eine brauchbare Obstpflanze ?

Abstract: A detailed description is given from the holly-leaved barberry plant (Mahonia aquifolia/Pursh/Nutt.), Berberidaceae or Berberis family. Its habitat is the pacific part of North America to Mexico, later indigenouses and cultivated as ornimental plant in Middle and West-Europe. The pea-greated, oval to chubby, steelblue riped fruits and the produced intensive red juice from it and used early as dye. The fruits and the dark red dye are practical alkaloidfree. Both products are not permitted as food dye in Germany and other countries. The Mahonia roots contained 2.4-4.5% whole alkaloids and are used medical by various skin diseasis.

Humanmilch-Untersuchungen 1980-1996 : Chlororganische Pestizide, Polychlorierte Biphenyle und Nitromoschusverbindungen

Abstract: Chemical contamination of human milk was studied using the data of more then 16 000 samples analyzed by the chemical state laboratories of Baden-Wurttemberg. The samples were received not systematically from interested women and were analyzed gratis. For the pesticides DDT, HCB and beta-HCH there is a clear and steady decline to 70-80% in the years 1980-96. PCB has a decline of 50%. The nitro musks which are surveyed since 1993 show a downward trend too. The distribution of all analytes is not a Gaussian. The median levels are below the average Levels. Some of the extreme high levels could be traced back to special nutrition circumstances.

Nickel-Eintrag aus Wasserkochern ins Trinkwasser

Abstract: The EU is planning to drop the threshold value for nickel in drinking water down to 20 μg/Il (present German threshold value: 50 μg/l). Since ICP-MS-screenings of spot checks of water cookers were striking with respect to nickel, emissions of electrical water cookers have been investigated systematically within this study. As a result, water cookers with open heating coils are emitting relevant amounts of nickel into the water while it is brought to the boil. Investigation of eight preused water cookers with open heating coils revealed that the boiled water contained more than 50 μg Ni/l in one case, more than 20 μg Ni/l in two cases and, between 10 and 20 μg Ni/l two more cases, respectively. Removing of the lime by the aid of citric acid is increasing the nickel concentrations by a factor of up to 50 (max. 640 μg/l). A new device was checked in a long-term test. During standard use with tapwater, Ni concentrations fall below the detection limit of 5 μg Ni/l (120 cooking events). However, after removing of the lime, 5 times of cooking were necessary in order to diminish the Ni concentrations below the limit of 20 μg/l. In the case of deionized water Ni conentrations remained between 94 und 190 μg/l. Health risk assessment: the intake of nickel with beverages made from hot water out of these cookers is in the range of 26 μg/day. Considering an alltogether dietary nickel intake of 130-170 (900) μg/day, this is not beyond the scope. However, according to the fact that nickel allergies (dermatitis) are very frequent (up to 13% of the population), this source should be limited or closed.

Untersuchungen über charakteristische Inhaltsstoffe in Destillatfraktionen aus Obstmaischen, die als Leitsubstanzen zur sicheren Erkennung von Nachläufen geeignet sind

Abstract: The distillation characteristics of the individual volatile fatty acids, especially acetic acid, C6-C12 and C3-C5 fatty acids and the other poorly volatile compounds such as 2-phenylethanol, ethyl lactate and middle and long chain esters etc, were studied using GC analysis after the fractionated collection of the distillate from numerous fruit mashes. It could be shown that the volatile fatty acids were the most important compounds in tailing with respect to quantity as well as being the main cause of the,,off flavour of tailing, whereby the character impact compounds or key compounds of tailing could be ascribed to the C6-C12 fatty acids. The C3-C5 fatty acids as well as acetic acid could intensify this ,,off flavour, especially in the distillate from infected mash. The other tailing compounds such as 2-phenylethanol, ethyl lactate, long chain esters etc, probably contributed to some extent to the ,,off flavour of tailing but were not as important as the C6-C12-fatty acids.

Vinclozolinrückstände in pflanzlichen Lebensmitteln : Schnelle Bestimmung des Gesamtrückstandes durch GC-MS

Abstract: In an automatically working apparatus for SDE (steam-distillation-extraction) plant foods are hydrolysed by alkali to extract vinclozoline residues including metabolites contented the 3,5-dichloroaniline group. The determination was accomplished by GC-MS without other cleanup. The standard deviation for a sample of lettuce with 0.166 mg/kg vinclozoline by 5-times execution of the described procedure is 0.01. The variation coeffizient is 1%. The recoveries of fortifications of 0.1 mg/kg were determinated with 100%, 118% or 99% for crushed grain, carrots and lettuce and with 60% for beans. Opposite to methods only registering non decomposed vinclozoline, residue levels increase considerable, in carrots partically clearly about the legal limit.

Bestimmung von α-Hydroxysäuren in kosmetischen Mitteln

Abstract: A method for the determination of α-hydroxy acids in cosmetics by HPLC is presented. It comprises a simple method of sample preparation by extraction with an acidified mixture of solvents and subsequent chromatographic separation on RP-8-phase with UV-detection at 210 nm.

Effects of freeze-drying on the compositions of green beans and Padrón peppers

Abstract: The concentration of vitamin C, organic acids, pigments and carbohydrates was determined in fresh and freeze-dried beans and Padron peppers (and monitored during 12 month's storage of the freeze-dried vegetables). Freeze-drying had decreased the content of vitamin C (virtually to zero), malic, citric and oxalic acid. The content of fumaric and quinic acid (the latter was only detected in peppers) was increased. During storage of the freeze-dried vegetables the concentration of organic acids was nearly constant. We could show as well a decreasing of the pigments expecially in freeze-dried beans. A further decrease of concentration of chlorophyll a and b and lutein occurred in the first month, of β-carotene during the second month. Afterwards the content of pigments was nearly constant until the end of the 12 months. The amount of soluble sugars, starch and pectins was hardly affected by freeze-drying and subsequent storage. Looking at the content of insoluble fibre, which was essentially unaffected by freeze-drying, we could show an increase between the second and third month of storage and then a fluctuation about a three-month level until the end of the 12 month cyclus.

Kapillarelektrophoretische Bestimmung des Phytinsäuregehaltes von Tempeh und den Zwischenprodukten der Herstellung dieses Fermentationsproduktes der Sojabohnen

Abstract: The charge in the phytic acid content of soybeans during the tempeh production, which is soaking, cooking, steaming and fermentation of soybeans, was determined by capillary electrophoresis. The phytic acid content in soybeans remained unchanged by soaking. It slightly decreased after cooking and steaming. Finally it was strongly reduced by the fermentation. Using capillary electrophoresis the phytic acid content of food extracts can directly be determined. Degradation products of phytic acid and other sample components do not interfere and are not coveraged. The decrease in phytic acid content after fermentation and as a result the increase in phosphate are clearly shown.