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Fifteen laboratories collaboratively determined parathion, o,p'-DDT, p,p'-DDT, and p,p'-DDE in kale, and lindane, dieldrin, heptachlor epoxide, and p,p'-DDE in eggs, using electron capture gas-liquid chromatography (potassium chloride thermionic detector for parathion). Pesticide levels ranged from 0.033 ppm heptachlor epoxide to 3.32 ppm p,p'-DDT. Mean recoveries (+/- standard deviations) were: parathion 91+/-15%, o,p'-DDT 99+/-8%, P,P'-DDT 97+/-8%, lindane 94+/-4%, dieldrin 106+/-8%, heptachloro epoxide 106+/-5%, p,p'-DDE 94+/-8% in eggs and 101+/-9% in kale. The methods have been adopted as official first action.

Standard Tables of Food Composition in Japan--Fourth Revised Edition--were issued to the public in October 1982. The data for vitamin A include chemically determined preformed vitamin A and provitamin A. Vitamin A values in the tables are shown as micrograms of retinol and/or micrograms of carotene and also as international units of retinol potency per 100 g edible portion of the foods. The term "carotene" is used for the total mixed carotenoids with vitamin A activity analyzed. In fact, the carotenes analyzed consisted of a large portion of beta-carotene and a small portion of alpha-carotene. One retinol potency (IU) is equivalent to 0.3 micrograms of retinol or 1.8 micrograms (0.6 micrograms X 3) of carotene, which means that the biologic activity of carotenoids is considered to be one-third that of retinol, mainly due to the inferior absorption of carotene. However, as an exception, in milk and dairy products 1 IU is considered to be equivalent to 0.6 micrograms of carotene. As for the foods for which both retinol and carotene contents are given in the table, the retinol potency is calculated by addition of values derived from both retinol and carotene. There are considerable differences in vitamin A values of some foods between the third revised edition and the fourth revised edition of the Standard Tables of Food Composition in Japan. The mean daily vitamin A intake of Japanese people as determined by the recent national nutrition survey was 2,120 IU when the calculation was made from the data in the fourth revised edition and 1,762 IU when the calculation was made from the data in the third revised edition, indicating approximately a 20% larger value in the former than the latter. This fact has to be taken into consideration in the comparison between new data and previous data from nutrition surveys.

A procedure was developed to measure the degree of pectin methylation in small samples of isolated cell walls from nonlignified plant tissues or pectin solutions. Galacturonic acid was determined colorimetrically with the 3,5-dimethylphenol reagent. Methylation was measured by base hydrolysis of galacturonic acid methyl esters, followed by gas chromatographic determination of released methanol. Estimates of the precision of analysis of pectin and cell wall samples were made. The coefficient of variation for estimates of the pectin esterification in cell walls isolated from 10-g samples of cucumber tissue ranged from 7.7 to 13.2%.

The authors determine the content of nitrates in soil samples and the vegetables grown on them (lettuce, spinach, onion, garlic) via sensitive spectrophotometric methods with phenodisulphonic acid and reduction with cadmium column. The lowest nitrates content was established in the soil samples and vegetables grown by AIC, followed by the private arms, and the highest - in the green-horse vegetables and soil samples, owing mainly to the technology of production.

Transfer factors have been measured for 239 Pu + 240 Pu, 241 Am, 90 Sr and 137 Cs into potatoes grown in a blend of soil which included silt polluted with radioactive waste discharged into the Irish Sea. The experiment has been carried out over four seasons and attempts to assess the radiological consequences to the consumer which would arise if potatoes were to be grown in land heavily contaminated with the silt. During the course of the experiment plutonium and americium became less available for uptake, 90 Sr became slightly more available and 137 Cs remained nearly constant in its availability. The values of the transfer factors are among the lowest reported for these radionuclides into potatoes.

A rapid, sensitive polarographic method is presented for determining sulfiting agents in foods and beverages. The method is based on the modified Monier-Williams distillation followed by polarographic detection by differential pulse polarography or square wave voltammetry. A clearly defined wave is obtained by both techniques, with a current maximum at a potential (E) of about -600 mV vs an Ag/AgCl reference electrode. The reaction is based on the reduction of sulfur dioxide at a dropping mercury electrode. Peak current was linear over the range 0-20 micrograms/mL. Quantitation is done by linear regression analysis of standard addition data or by using a standard calibration graph. Screening levels of less than 1 ppm total SO2 were easily achieved in the foods analyzed, which had levels from less than 1 ppm (cereals) to thousands of parts per million (dried fruit). Recoveries from fortified samples ranged from 70 to 108% at fortification levels of 20, 100, and 1000 micrograms/g.

The authors developed a thin-layer chromatographic technique for the separation of carbamate pesticides from plant material and an enzymatic method for their determination. The cellulose plates were impregnated with polar substances (ethylene glycol, triethylene glycol and beta,beta'-oxydipropionitrile). n-Heptane/chloroform and iso-octane/dioxane served as solvents. The slight enzyme-inhibiting effect and the colouration of the plant extracts render the detection of the pesticides difficult. Nevertheless, the separation and the enzymatic detection of Methomyl, Carbaryl, Baygon and Aldicarb could be achieved. The Rf values of the carbamates are not influenced by the kind (apples, pears, onions) and the quantity (50--200 mg) of the plant material.

Comparison of the evidence on the content of nitrates and ascorbic acid in vegetables and fruits shows that the content of ascorbic acid in fruits exceeds that of nitrates whereas in a number of vegetables the nitrate content is greater than that of ascorbic acid. With increase in the amount of nitrogen fertilizers introduced, the content of nitrates in vegetables grows more intensively as compared to ascorbic acid. The range of these variations is relative to the type and grade of vegetables. During the storage of beet and cabbage the decreased content of ascorbic acid correlated well with the amount of nitrogen-containing mineral fertilizers introduced. It is recommended that fruits and berries be used first of all as a source of ascorbic acid, while rhubarb, fall radish and salad be restricted in the diet.

Four composite diets from three cities, each representing the daily per capita consumption of foods in Canada, contained on analysis 191, 220, 113, and 150 mug selenium. Cereals provided the most selenium (62-112 mug) followed by meat, poultry, and fish (25-90 mug) and dairy products (5-25 mug). The average daily intake of selenium in Canada was also calculated from published analytical data and the per capita disappearance of unprepared foods. The total intake was 197 mug/day, and the major sources were wheat flour (98 mug), pork (21 mug), poultry products (24 mug), and fish (17 mug). Because the average diet is rich in selenium, the possibility of a deficiency in the adult is considered to be remote. Milk is relatively low in selenium, and thus the greatest deprivation in humans would occur during infancy.

A simple and efficient cleanup method for gas chromatographic determination of 23 organophosphorus pesticides in crops including onion is described. The sample was extracted with acetone. The extract was purified with coagulating solution, which contained ammonium chloride and phosphoric acid, and then filtered by suction. The filtrate was diluted with NaCl solution and reextracted with benzene. The organic layer was evaporated and injected into a gas chromatograph equipped with a flame photometric detector (FPD) and fused silica capillary columns (0.53 mm id) coated with silicone equivalent to OV-1701, OV-1, and SE-52. Onion extract, which contained FPD interferences, was cleaned up on a disposable silica cartridge. Recoveries of most organophosphorus pesticides from spiked crops: mandarin orange, tomato, spinach, sweet pepper, broccoli, lettuce, and onion at levels of 0.02-0.28 ppm, exceeded 80%, but the water-soluble pesticides dichlorvos and dimethoate gave poor recoveries in all crops; the nonpolar pesticides disulfoton, chlorpyrifos, fenthion, prothiophos, and leptophos were not recovered quantitatively in spinach, sweet pepper, broccoli, and lettuce. IBP, edifenphos, phosmet, and pyridaphenthion were not recovered from onion because of adsorption to the silica cartridge. The detection limits ranged from 1.25 to 17.5 ppb on a crop basis.

Ethyl acetate and diethyl ether were compared for their ability to recover Ascaris spp. and Trichuris spp. eggs from seeded milorganite, liquid sludge, and cabbage. Concentrations of 10, 100, and 1000 eggs/10 g test sample were prepared for 20 replicates of each product. The use of diethyl ether yielded fewer eggs/10 g than did ethyl acetate in 5 of 6 sets of data. For Ascaris spp., recovery from cabbage was 10 times higher with ethyl acetate at the higher concentration than with diethyl ether. For Trichuris spp., recovery from liquid sludge was slightly higher with diethyl ether for all egg concentrations. The other results ranged from 0 to 23% difference in recovery for the 2 agents. Depending on the parasites in question and the products to be screened, the substitution of ethyl acetate for diethyl ether may be significant.

The content of benz(a)pyrene (BP) in the soil of the agricultural regions of the USSR, away from the intense sources of industrial wastes ranges within 1-10 microgram/kg and depends on the soil type. In the vicinity of the industrial enterprises, the BP content in the soil may be tens thousand times higher. The baseline natural content of BP in the green parts of the vegetables constitutes 1-5 microgram/kg, while in the grain, seeds and fruit it is 10-100 times lower. In the vicinity of the sources of industrial wastes, the BP content in the green parts of the vegetables, in the grain, seeds and fruit was found to be drastically increased. There is a correlation between the BP content in the potato tubers and the soil where the potato is grown.

Aldicarb, Temik 15 G, was incorporated in furrows at 3.37 and 6.73 kg ai (active ingredient)/ha and carrots (Daucus carota L.) were directly seeded on the same day. The numbers of nematode larvae were significantly suppressed in the treated plots; averages were 249, 74, and 51/50 cc soil samples for control (0), 3.37 and 6.73 kg ai/ha, respectively. Aldicarb treatment resulted in a 28% yield increase as compared to the untreated. Aldicarb residue in carrots was 28 ppb for the low treatment and 46 ppb for the high. Residual levels in soil of high treatment declined from 61 to 31 ppb during two weeks prior to harvest, meanwhile, those in the low decreased slightly from 13 to 12 ppb. Carrots placed in hydroponic solution containing aldicarb 14.5 ppm for 6 days, had an aldicarb residue of 10.26 ppb and the hydroponic solution, 2.7 ppb. Persistence of aldicarb residue was in carrot greater than in soil greater than in hydroponic solution.

A procedure based on current multi-residue methodology is described for the determination of synthetic pyrethroid residues in vegetable and animal tissues. Permethrin, cypermethrin, and fenvalerate are extracted from celery, egg yolk, beef muscle, and milk with acetonitrile, partitioned into hexane, and cleaned up on Florisil for quantitation by electron capture gas chromatography. Recoveries of the 3 pyrethroids averaged 94-103% from celery and 82-97% from animal products. Minimum detectable levels of less than 5 ng/g are readily attainable. The method also allows for the simultaneous extraction and cleanup of the organochlorine hydrocarbon insecticides which have been routinely analyzed in the past.

The effect of organic solvent/water ratios on the extraction of field-incurred residues of dieldrin and methomyl from radishes was determined. 14C-Dieldrin and 14C-methomyl were applied separately to radishes in commercial formulations at rates of 0.2 and 0.9 kg/ha, respectively. Fourteen days post-application, the radishes were harvested and fresh root tissues were extracted using a Polytron homogenizer. Acetone, acetonitrile, and methanol containing 0, 10, 20, 30, 40, and 50% water were used as extraction solvents. For methomyl residues, the optimum water content of acetonitrile-water extraction mixtures was 40-50%; less than 40% water reduced the ability of acetonitrile to extract carbon-14. Methanol and acetone were nearly as efficient as 50% acetonitrile-water and were apparently not influenced by solvent/water ratios. For dieldrin, low water content slightly reduced the extraction efficiency of acetonitrile, with the optimum water content also being 40-50%. Percentage of water appeared to have little overall effect on methanol extraction efficiency. The extraction efficiency of acetone was lower than that of the other 2 solvents, and this effect was independent of the acetone/water ratio. Approximately 20% of the 14C-dieldrin residue was bound to radish roots 14 days post-application.

Male Sprague-Dawley rats were fed on purified diets supplemented with 50-500 ppm indole-3-carbinol (I3C), a compound present in cruciferous vegetables, or with 25% Brussels sprouts (Brassica oleracea) for 10 days after a 1-wk equilibration on a purified diet. Cytosolic and microsomal fractions were prepared from liver and intestinal mucosae. Intestinal aryl hydrocarbon hydroxylase (AHH) activity was increased significantly (P less than 0.05) over basal levels by I3C at 50 ppm (a 6.1-fold increase), at 125 ppm (11.8-fold), at 250 ppm (14.1-fold) and at 500 ppm (20.2-fold) and by 25% Brussels sprouts (3.6-fold). Intestinal ethoxycoumarin O-deethylase (ECD) activity was also significantly increased by I3C, the increases being 4.6-, 8.7-, 9.3- and 11.2-fold with 50, 125, 250 and 500 ppm I3C, respectively, and 3.2-fold with the sprouts diet. Hepatic AHH and ECD were not increased significantly by any of these dietary treatments. Hepatic and intestinal glutathione S-transferase (GST) activities were increased (P less than 0.05) 1.9- and 1.6-fold, respectively, by the sprouts diet but were not significantly affected even by 500 ppm I3C. Microsomal epoxide hydrolase (EH) activity of the small intestine was increased 2.0-fold by the sprouts diet but was unaffected by I3C. Hepatic cytochrome P-450 was increased 1.3-fold by the sprouts diet although I3C at 500 ppm only produced a 1.1-fold increase. A no-effect-level for I3C on intestinal monooxygenase induction was estimated to be between 16 and 25 ppm, supporting the contention that I3C can account for much of the monooxygenase induction observed when experimental animals are fed diets high in cruciferous vegetables. The results also indicate that Brassica oleracea contains other compounds which are responsible for the induction of GST and EH activities.

Levels of organochlorinated, organophosphate, dithiocarbamic, benzimidazolic, and phthalimidic compounds, as well as some other pesticide residues obtained from Regional Laboratories in the years 1983-1985, were assembled and presented as a part of a study aimed at evaluating food contamination. Approximately 2000 samples of vegetables, fruits, cereals, and food of animal origin were analyzed by local laboratories during the years 1983, 1984, and 1985. Samples were randomly obtained from the market, at production levels, or sometimes at custom sites. Approximately 10,000 determinations of single compounds or classes of compounds were carried out. The analytical results are presented and compared with the Italian maximum residue limits. In the majority of the samples analyzed, either there were no residues or the residues were below the permitted level for the specific pesticide in each commodity. High levels of residues were present in a few cases, mainly with respect to some fungicides in fruits and vegetables and chlorinated compounds in some animal products.

A proteinase inhibitor was isolated and partially purified from the exocarp of eggplant, Solanum melongena L., by means of acetate buffer extraction, heat treatment, salting-out and column chromatography on DEAE-cellulose. This preparation showed inhibitory activities on various proteinases; trypsin [EC 3.4.4.4] and Pronase were strongly inhibited while alpha-chymotrypsin [EC 3.4.4.5] and Nagarse were weakly inhibited. The inhibitor was a protein substance, and, therefore, it was gradually inactivated by the long-time incubation with Pronase. The inhibition mode was non-competitive on trypsin and competitive on Pronase on the basis of Lineweaver-Burk plots. The investigations on the inhibition behavior in the co-existence of two kinds of proteinases suggested that the inhibitor was not of multi-headed type.

The effect of fish protein and fish oil on the utilization of endogenous iron in wheat bran, spinach and soy protein isolate was investigated by using the anemic rat as an animal model. Marine products were substituted for casein and corn oil in the diets of these animals. Hemoglobin regeneration was one criteria used to measure iron uptake. Relative biological values (RBV) were computed from a regression equation obtained from control animals receiving graded levels of FeSO4 X 7H2O. The RBV of iron from plant sources provided in diets containing casein-corn oil versus fish-fish oil were: wheat bran, 123 vs. 111%; spinach, 53 vs. 49%; and soybean isolate, 84 vs. 67%; RBV FeSO4 = 100%. These changes were not significant. The decreases in iron absorption from diets containing marine products was attributed to the fish oil. Absorption of exogenous iron (59Fe) was measured in the same animals after the 14-day repletion period. Assimilation of the 59Fe was highly correlated (r2 = 0.958) with hemoglobin level at time of dosing. Diet composition did not appear to have the same effect on the percentage of 59Fe retained after 110 hours by the rat as compared to levels of hemoglobin regeneration (i.e., RBV). A "meat factor" effect was not shown by substituting fish for casein the diets containing plant iron sources fed anemic rats.

The chloride ion selective electrode is used for a rapid, simple, and reliable determination of chloride ion in biological materials (blood serum, urine, fish, and plant tissues), food products (milk, beef extract, nutrient broth and orange, tomato, and grapefruit juices), soils, and waste water (industrial and municipal). The method consists of treating the samples with perchloric acid (pH 1) and potassium peroxydisulfate and determining the chloride content either by a calibration curve or by known addition or analyte addition, using the chloride ion selective electrode. Such sample treatment eliminates most of the interferences occurring in the samples, including iodide, complexing and reducing compounds, and macromolecular and surface-active species. The method is suitable for a wide range of chloride concentration, e.g., 5010 ppm Cl- in nutrient broth and 4890 ppm in beef extract and as low as 12 and 80 ppm in soil extracts.