Mercury in fish (author's transl)]

The mercury content of fish was determined. The average mercury concentration of fresh fish muscular was found to be 0.239 ppm in 1400 examinations.     

A rapid method for determination of oil in lecithins (author's transl)]

A rapid method for routine determination of oil in commercial lecithins and similar phospholipid samples has been worked out. This based on the observation that under the described experimental conditions 1 g of phospholipids is completely adsorbed on 45 g silica gel which has previously been disactivated by the addition of 15% water. The lecithin sample is filtered in ethereal solution through a column filled with disactivated silica gel which is subsequently washed with a little ether. The combined ether eluates are evaporated to dryness invacuo and the residue weighed. This residue is the oil part of the sample and is constituted of mono-, di-, and triglycerides, free fatty acids, sterols and their derivatives. The duration for one such determination is about 20 min.     

Quantitative determination of supplemental vitamin C in mineral salt mixtures (author's transl)]

Supplemental vitamin C in mineral salt mixtures is extracted without destruction by diluted ethanol under the reducing and stabilizing protection of 2,3-dimercaptopropanol-(1) (BAL). After removal of heavy metal ions in form of mercaptides and by means of cation exchange BAL is extracted and vitamin C (ascorbic plus dehydroascorbic acid) titrated with dichlorophenolindophenol. Recovery 98-100%.     

Caffeine determination by gelchromatography (author's transl)]

Caffeine in beverages was determined by gel chromatography after extraction with chloroform from an alkalized sample. For extract from coffee, tea and matè a very good agreement was observed between the chromatographic method used and the method of Navellier et al. Major departures were observed for decaffeinized coffee and some beverages of the cola type, where gel chromatography was more selective and caffeine separated from impurities stripped into the extract. The reproducibility of determination corresponded to the standard method (standard deviation 4.2%).     

Photometric determination of arsenic in biological samples (author's transl)]

A modified method by means of absorption of AsH3 in chloroform with an addition of 0,5% hexamethylene-tetramine is described. The detection limit amounts to 0,5 mug arsenic. Arsenic contents of some higher burdened foodstuff are amended.     

Simultaneous, gas-chromatographic determination of ethyleneoxide, ethylenechlorohydrine and ethyleneglycol in grain (author's transl)]

The not comminuted grain (10 g) is extracted for 24 hrs (25 degrees C) with 5 ml methanol (shaking machine), then the fluid phase is separated by centrifugal filtration and directly injected into the GC (10 mu). The GC starting temperature (60 degrees C) is adjusted by cooling the oven with Co2. Yield: EO 73% (concentr. range 25 ppm); ECH 93% (concentr. r. 50 ppm); EG 99% (conc. r. 50 ppm). Standard deviation: EO s = +/- 1,70 ppm (N = 24, conc. r. 10 ppm), ECH s = +/- 1,15 ppm (N = 24, conc. r. 20--30 ppm), EG s = +/- 0,62 ppm, (conc. r. 15--30 ppm, N = 24).     

Lead-contents in mushrooms (author's transl)]

The lead-contents of canned and fresh mushrooms were analyzed by photometric determination after dry ashing and dithizone extraction. The average lead-content was found to be 0.49 ppm with extreme values of 0.10--1.0 ppm on fresh-weight basis resp. 5.5 ppm (2.0--13.5 ppm) on dry-weight basis. It appears that lead content increases with the size (age) of the mushrooms; the influence of canning upon the lead content is not yet finally clear, it seems, however, as if canning process has a lesser influence on the lead content than the size (age) of mushrooms.     

Polyphenols in brewing (author's transl)]

Analytical methods for the determination of polyphenols of malt, barley, hop, wort, and beer are described. Malt or barley tannins has hitherto not received as much study as hop tannin. Polyphenols or tannins are classified. Studies on non-biological hazes are discussed in relation to the haze problem in brewing. The leucoanthocyanins of malt differ from those of hops in ability to form hazes. Subfractionation of polyphenol concentrates on sephadex columns allows isolation of individual tannins.     

Simultaneous determination of lysine, lysinoalanine, furosine, and pyridosine in food and feed (author's transl)]

A method for the simultaneous separation and determination of lysinoalanine (LAL), lysine, furosine and pyridosine with an automatic amino acid analyzer using a single Column 4 buffer- and 3 temperature-programme is described. The procedure needs 160 Minutes analysis time and allows a separation and quantitative determination of LAL, when present in amounts of more than 100 ppm (semiquantitative above 10 ppm). All amino acids found in food proteins and all other ninhydrinpositive compounds tested until now do not interfere with the determination.     

Determination of zeranol in meat (author's transl)]

A qualitative and quantitative method for the determination of zeranol in meat and liver is described. The analysis procedure includes methanol extraction, enzymatic hydrolysis of possibly existing conjugates, and liquid-liquid partition, followed by two-dimensional thin layer chromatography. Zeranol is selectively made visible as a red-violet spot with Fast Blue B salt. The detection limit in meat is found to be 10 ppb. For the quantitative determination zeranol is eluted from the TLC plates and reacted with Fast Blue B salt. A quantitative determination can be performed with a concentration of 0.4 ppm. The application of this method demonstrated the presence of zeranol in 2 out of 18 commercially obtained samples.     

On the determination of coffeine in soft drinks and coffeine-containing food preparations (author's transl)]

The recently proposed spectroscopical determination of coffeine in soft drinks after filtration of polyamide leads to higher coffeine values than originally present, due to substances absorbed by the UV light. Therefore a method is proposed for identification and quantitative determination of coffeine in soft drinks and in methanol extracts of coffeine-containing foods by column chromatography on silical gel.     

Analytical characterization of palatinit (author's transl)]

The reaction product of the catalytic hydrogenation of isomaltulose (palatinose) is a mixture of alpha-D-glucopyranosido-1,6-sorbitol and alpha-D-glucopyranosido-1,6-mannitol designated palatinit. Because of its high potential as a sugar substitute methods for the identification and characterization of hydrogenation products and for the determination of palatinit as an ingredient in food preparations and biological samples are required. Several working procedures are described in full detail including thin layer and gas chromatography as well as enzymatic and chemical determinations.     

PR-Toxin-production of Penicillium roqueforti-Strains (author's transl)]

One blue-type cheese starter and 11 isolates of P. roqueforti from different foodstuffs were tested for the production of PR-toxin. 3 strains were able to produce the toxin on rice at 15 degrees C and sometimes at 30 degrees C. The toxin quantities detected were 310-960 ppb. The starter culture didn't produce any PR-toxin. The investigations with P. roqueforti NRRL 849 showed a toxin-production in the temperature range of 15-30 degrees C, with an optimum at 15 degrees C, whereas 25 degrees C was the optimum for growth. PR-toxin was determined by thin-layer-chromatography and in doubtful cases by mass-spectrometry.     

Phospholipase D of cereals (author's transl)]

Phospholipase D containing water insoluble fraction was isolated from mature barley; the enzym preparation only had weak phospholipase B activity. The phospholipase D of barley was activated by Ca2+, diethyl ether and sodium dodecyl sulphate (SDS); EDTA inhibited the enzyme to an extent of 10% of the original activity. Diethyl ether and SDS showed and additive effect. Phospholipase D activated by CaC12, diethyl ether and SDS exhibited a sharp optimum at pH 6.6. Lysophosphatidylcholine was hydrolysed much slower than phosphatidylcholine. Diethyl ether and SDS also increased the breakdown of the lysophosphatidylcholine.     

About mass-spectroscopy of aflatoxines (author's transl)]

The mass-spectroscopical identification of aflatoxines in the eluant after thin-layer-chromatographical seperation represents a problem at amounts of less than 50 ng normally found in foods. Therefore it was necessary to investigate the factors influencing the identification. Among others, influences of plate material and the eluant were found. Based on the results with pure aflatoxines ideas were developed on their possible reactions.     

Pesticide residues in poppy seed (author's transl)]

131 samples of poppy seed imported in 1977, 1978, and 1979 were analyzed for organochlorine pesticides. The average and maximum residue levels were 0.05 and 0.42 ppm for BHC-isomers without lindane, 0.07 and 0.40 ppm for lindane, 0.016 and 0.14 ppm for total DDDT (DDT, DDD, and DDE). Other pesticides could not be detected. The residue level was much higher in the first half year of our examination. Poppy seed from Eastern Europe and Turkey showed appreciably higher contamination than imports from Western European countries.     

Vitamin A in irradiated foodstuffs (author's transl)]

Vitamin A losses induced by 10 MeV electrons in cream cheese, calf liver sausage, pig liver, whole egg powder and margarine continued to increase during storage for 4--8 weeks in presence of air. Thus vitamin A loss in sausage irradiated with 5 Mrad was 22% on the day after irradiation, 61% after 4 weeks. Irradiation and storage at 0 degrees C instead of at ambient temperature reduced these losses considerably. Exclusion of air (vacuum, nitrogen) or irradiation on dry ice (approx. -80 degrees C) were even more effective in preventing destruction of vitamin A. After 4 weeks of storage, cream cheese irradiated at 5 Mrad had lost 60% when irradiated and stored in air at ambient temperature, 20% in nitrogen atmosphere, 5% in vacuum package, and 5% when irradiated on dry ice and stored at ambient temperature.     

The determination of saccharin by gas chromatography after methylation with diazomethane (author's transl)]

Saccharin may be determined by gas chromatography after methylation with diazomethane. In this reaction there are found N-methyl-saccharin, and the O-methyl ether as well as methoxycarbonyl benzenesulfonamide by ring fission.     

To the determination of chlorinated hydrocarbon pesticide residues with capillary chromatography (author's transl)]

A procedure for determinting chlorinated hydrocarbon pesticide residues by gaschromatography with capillary columns in feeds is described. With the capillary column (OV 61) used a good resolution of all tested 15 pesticides was possible. Recovery and reproducibility were checked, detection limits are given.     

Lead content of Hungarian wines (author's transl)]

The authors have investigated the lead content of 560 hungarian wines produced between 1969 and 1973 by atomic absorption spectrophotometry (Type of instrument: UNICAM SP 1900). The preparation of samples was made by wet digestion with HNO3-H202. For 94.12% of the investigated wines less than 0.4 ppm lead content was established. The 2.67% of wines contain 0.4-0.6 ppm lead. In case of 18 samples (3.21%) more than 0.6 ppm lead content was found.