[Radiation-hygienic evaluation of vegetables and potatoes grown after soil irrigation with water containing artificial radionuclides]. / Radiatsionno-gigienicheskaia otsenka ovoshchnoi produktsii i kartofelia, vozdelyvaemykh pri oroshenii vodami, soderzhashchimi iskusstvennye radionuklidy.

Radiation and hygienic appraisal of vegetables cultivated under various kinds of irrigation is presented. Critical radionuclides are determined along with major vegetable products owing to which the great amount of radionuclides is absorbed. Contribution of vegetables and potato cultivated under irrigation into the total body intake of radionuclides by local residents has been evaluated.

A further study of oxalate bioavailability in foods.

We extended the study of oxalate bioavailability by testing 7 additional food items: brewed tea, tea with milk, turnip greens, okra, peanuts and almonds. Nine normal subjects ingested a large serving of each of these items. The bioavailable oxalate was calculated from the increment in urinary oxalate during 8 hours after ingestion and bioavailability was determined as the percentage of total oxalate content in a given food item represented by bioavailable oxalate. Brewed tea and tea with milk, with a high oxalate content, had a low bioavailable oxalate level (1.17 and 0.44 mg. per load) because of the low oxalate availability (bioavailability of 0.08 and 0.03%). Turnip greens, with a satisfactory oxalate bioavailability (5.8%), had a negligible effect on urinary oxalate excretion, since oxalate content was relatively low (12 mg. per load). Okra, with a moderate oxalate content (264 mg. per load) had a negligible bioavailable oxalate (0.28 mg. per load). Only peanuts and almonds provided a moderate increase in oxalate excretion (3 to 5 mg. per load) due to the modest oxalate content (116 and 131 mg. per load) and oxalate bioavailability (3.8 and 2.8%). Thus, the ability of various oxalate-rich foods to augment urinary oxalate excretion depends not only on oxalate content but on the bioavailability.

Effect of calcium glucarate on beta-glucuronidase activity and glucarate content of certain vegetables and fruits.

Glucarate is normally present in tissues and body fluids and is in equilibrium with D-glucaro-1,4-lactone, a natural inhibitor of beta-glucuronidase activity. Dietary calcium glucarate, a sustained-release from of glucarate, elevates the blood level of D-glucaro-1,4-lactone which suppresses blood and tissue beta-glucuronidase activity. A single dose of CaG (4.5 mmole/kg body weight) inhibited beta-glucuronidase activity in serum and liver, lung, and intestinal microsomes by 57, 44, 37, and 39%, respectively. A chronic administration of calcium glucarate (4% in diet) also decreased beta-glucuronidase activity in intestinal and liver microsomes. Maximal inhibition of beta-glucuronidase activity in serum was observed from 12 noon to 2:00 PM. In contrast, maximum inhibition of beta-glucuronidase activity in intestinal and liver microsomes occurred during mornings, although a secondary depression in intestinal microsomes also occurred around 4 PM. A 4% calcium glucarate supplemented diet also inhibited beta-glucuronidase activity by 70% and 54%, of the bacterial flora obtained from proximal (small intestine) and distal (colon) segments of intestine, respectively. Due to the potential effect of dietary glucarate on net glucuronidation and on other metabolic pathways, glucaric acid levels in various foods were determined. The glucaric acid content varied from a low of 1.12-1.73 mg/100 g for broccoli and potatoes to a high of 4.53 mg/100 g for oranges.

[Nitrates in vegetables--proposals for their limitation in Poland]. / Azotany w warzywach--propozycje limitowania w polsce.

Maximal permissible amounts of nitrates in vegetables and potatoes in Poland are proposed. These food products were divided into four groups according to their ability of accumulation of these substances. Moreover, a group of vegetables from special raising plots was isolated, they would be used for feeding small children, patients, and elderly subjects which would have a declared higher health quality.

Natural pesticides and bioactive components in foods.

In this review, some common food plants and their toxic or otherwise bioactive components and mycotoxin contaminants have been considered. Crucifers contain naturally occurring components that are goitrogenic, resulting from the combined action of allyl isothiocyanate, goitrin, and thiocyanate. Although crucifers may provide some protection from cancer when taken prior to a carcinogen, when taken after a carcinogen they act as promoters of carcinogenesis. The acid-condensed mixture of indole-3-carbinol (a component of crucifers) binds to the TCDD receptor and causes responses similar to those of TCDD. Herbs contain many biologically active components, with more than 20% of the commercially prepared human drugs coming from these plants. Onion and garlic juices can help to prevent the rise of serum cholesterol. Most herbs used in treatments may have many natural constituents that act oppositely from their intended use. Some herbs like Bishop's week seed contain carcinogens, and many contain pyrrolizidine alkaloids that can cause cirrhosis of the liver. The general phytoalexin response in plants (including potatoes, tomatoes, peppers, eggplant, celery, and sweet potatoes) induced by external stimuli can increase the concentrations of toxic chemical constituents in those plants. In potatoes, two major indigenous compounds are alpha-solanine and alpha-chaconine, which are human plasma cholinesterase inhibitors and teratogens in animals. Because of its toxicity, the potato variety Lenape was withdrawn from the market. Celery, parsley, and parsnips contain the linear furanocoumarin phytoalexins psoralen, bergapten, and xanthotoxin that can cause photosensitization and also are photomutagenic and photocarcinogenic. Celery field workers and handlers continually have photosensitization problems as a result of these indigenous celery furanocoumarins. A new celery cultivar (a result of plant breeding to produce a more pest-resistant variety) was responsible for significant incidences of phytophotodermatitis of grocery employees. Since there is no regulatory agency or body designated to oversee potential toxicological issues associated with naturally occurring toxicants, photodermatitis continues to occur from celery exposure. Sweet potatoes contain phytoalexins that can cause lung edema and are hepatotoxic to mice. At least one of these, 4-ipomeanol, can cause extensive lung clara cell necrosis and can increase the severity of pneumonia in mice. Some phytoalexins in sweet potatoes are hepatotoxic and nephrotoxic to mice. The common mushroom Agaricus bisporus contains benzyl alcohol as its most abundant volatile, and A. bisporus and Gyromitra esculenta both contain hydrazine analogues. Mycotoxins are found in corn, cottonseed, fruits, grains, grain sorghums, and nuts (especially peanuts); therefore, they also occur in apple juice, bread, peanut butter, and other products made from contaminated starting materials.(ABSTRACT TRUNCATED AT 400 WORDS)

Microscopic detection and identification of various substitute vegetable tissues in ground horseradish.

Turnip root, parsnip root, potato tuber, and corn kernels have been used as adulterants in the preparation of horseradish sauce and horseradish powder. The diagnostic histological features of horseradish root and its known adulterants are described and illustrated as viewed through a polarizing microscope with cross polars and a first order red plate. A procedure which can be used to detect any of the known adulterants in horseradish is described. The adaptation of a previously reported semiquantitative method is also discussed.

The daily dietary selenium intake of West German adults.

The selenium content of food consumed in the Federal Republic of Germany (FRG) was determined for the estimation of the dietary selenium intake of West German adults. The daily dietary selenium intake of men is 47 micrograms (micrograms) and that of women 38 micrograms, corresponding to 0.67 microgram/kg body weight per day for both men and women. Animal protein is the main source of dietary selenium, accounting for 65.5% of the total selenium intake. Pork contributes 25.1% to the total Se intake, reflecting the current consumption and the selenium supplementation of feedstock rather than the availability of selenium from natural dietary sources. The selenium intake of adults in West Germany is only slightly higher than in New Zealand, Finland, and Italy, nearly equal to that in Belgium and France, and distinctly lower than in Great Britain, the USA, Canada, and Japan.

Formation of mutagenic N-nitroso compounds in vegetable extracts upon nitrite treatment: a comparison with the glucosinolate content.

More than 30 vegetables were screened for their potential to form biologically active N-nitroso compounds upon treatment with nitrite under acidic conditions. The total N-nitroso content was determined in the nitrite-treated and untreated extracts of the vegetables according to a modified method of Walters et al. (Analyst, Lond. 1978, 103, 1127). All treated extracts contained N-nitroso compounds at levels ranging from 23 to 789 nmol/25 mg dry matter. In the same samples the mutagenic activity was determined using the Salmonella typhimurium assay. About half of the vegetables were found to be mutagenic upon nitrite treatment. (Nitrite-treated extracts were considered to be mutagenic if the number of induced revertants was at least twice as high as that induced by the corresponding untreated extract). The content of different glucosinolates in the dry matter of the vegetables was also determined. Glucosinolates could be detected only in cruciferous vegetables, at levels ranging from 1.8 to 26.0 mumol/g dry matter. Although the nitrite-treated extracts of brassica species contained more N-nitroso compounds and induced more revertants than did other vegetables, there was no significant correlation between these parameters. However, the amounts of N-nitroso compounds formed upon nitrite treatment (expressed per fresh weight) did correlate significantly (P less than 0.01) with the amounts of glucosinolates (r = 0.95). When the glucosinolates were divided into aryl/alkyl- and indolyl-glucosinolates, the significant correlation was maintained for both subgroups (r = 0.93 and 0.95, respectively). From this it can be concluded that glucosinolates are probably involved in the formation of N-nitroso compounds in certain nitrite-treated vegetables.

Studies on the tolerance limit of fluoride in food in China.

To estimate the appropriate tolerance limit of fluoride in food in China, fluoride-related endemic diseases, background levels of fluoride in foods, and daily total intake of fluoride per capita were studied in addition to the subchronic toxicity test of fluoride in rats. In the general population, the daily total intake of fluoride from food, water, and air is 1.45-3.15 mg per capita. On the basis of these results and other information, it is suggested that the ADI of fluoride in the Chinese population should be 3.5 mg per capita, or 0.058 mg/kg body wt, and the tolerance limit of fluoride should be 1.0 ppm in rice, wheat flour, vegetables, and freshwater fish.

Sensitivity to sulfited foods among sulfite-sensitive subjects with asthma.

Eight individuals with asthma who had been diagnosed as sulfite sensitive on the basis of double-blind capsule-beverage challenges were subjected to challenges with various sulfited foods, including lettuce, shrimp, dried apricots, white grape juice, dehydrated potatoes (as mashed potatoes), and mushrooms. Four of these patients failed to respond to challenges with any of the sulfited foods. The other four patients experienced a decrease in pulmonary function on double-blind challenges with sulfited lettuce. Two of three of these patients reacted to challenges with dried apricots and white grape juice; the fourth patient has not yet been challenged with these products. Only one of these four patients reacted to challenges with dehydrated potatoes and mushrooms, and, in this case, the response to double-blind challenges with dehydrated potatoes was not consistent. None of the sulfite-sensitive subjects with asthma responded to challenges with sulfited shrimp. It is concluded that sulfite-sensitive subjects with asthma will not necessarily react after ingestion of sulfited foods. The likelihood of a reaction is dependent on the nature of the food, the level of residual sulfite, the sensitivity of the patient, and perhaps on the form of residual sulfite and the mechanism of the sulfite-induced reaction.

Dietary fiber content of selected foods.

Dietary fiber measurements are essential to assessment of the potential therapeutic and preventive effects of fiber intake. Ideally, dietary fiber analyses should measure all components--soluble polysaccharides, noncellulosic polysaccharides, cellulose, and lignin--and the constituent sugars of the soluble and noncellulosic polysaccharides. We modified existing techniques to measure reproducibly the total dietary fiber, polysaccharide, and lignin components and the sugar constituents of selected foods. Soluble-fiber content as percentage of total dietary fiber for groups of foods averaged 32% for cereal products, 32% for vegetables, 25% for dried beans, and 38% for fruits. Lignin content, estimated gravimetrically, was approximately 1.4 g/100 g dry wt for 24 foods. Detailed fiber measurements are critical for evaluating the potential health benefits of dietary fiber intake.

Carrot phytoalexin alters the membrane permeability of Candida albicans and multilamellar liposomes.

The biochemical basis for the antimicrobial effect of the carrot phytoalexin 6-methoxymellein (6-MM) was examined. At fungistatic concentrations 6-MM retarded the ability of Candida albicans to incorporate radioactive thymidine, uridine and leucine into biopolymers. When C. albicans was incubated with 6-MM, 260-nm-absorbing materials and 3H-labelled compounds leaked from the cells. The inhibitory effects of 6-MM on cell growth and membrane functions were, however, reduced as the concentration of divalent metal cations added to the medium was increased. 6-MM interacted with multilamellar liposomes constituted from phosphatidylcholine, cholesterol and dicetyl phosphate, or from phosphatidylcholine only, resulting in the release of glucose trapped in these liposomes. These results suggest that 6-MM exerts its toxic effects on susceptible cells as a result of its interaction with their membranes and disturbance of membrane-associated functions.

High-performance liquid chromatography analysis of 1-aminocyclopropane-1-carboxylic acid using o-phthaldialdehyde precolumn derivatization.

A simple, rapid, direct method for the HPLC analysis of 1-aminocyclopropane-1-carboxylic acid (ACC) as its o-phthaldialdehyde derivative is described. The method is sensitive to about 1 pmol and can be used on plant tissue extracts with no cleanup. It will prove valuable in plant extracts where the chemical conversion of ACC in the tissue extracts to ethylene is variable, or when analyzing the specific radioactivity of ACC produced from radiolabeled precursors.

Water soluble high molecular weight components from plants with potent intraocular pressure lowering activity [corrected and republished ariticle originally printed in Curr Eye Res 1987 May;6(5):733-4].

Previous work in our laboratory has shown that Cannabis sativa (marijuana) contains water-soluble, high molecular weight components that have extremely potent intraocular pressure (IOP) lowering activity. Aqueous extraction of other plants has now shown that a number of them also contain components with potent IOP lowering activity in rabbits. These include tobacco, cabbage, lettuce, several greens, Senecio anonymus, Erigeron philadelphicus, and several others. Not all plants tested were active, however, indicating that while more ubiquitous than originally thought, these materials are not apparently extractable from all plants. The chemical composition of the active fraction from tobacco was found to be different from that derived from Cannabis sativa.

Environmental impact of particles emitted from Windscale Piles, 1954-7.

During 1954-7 particles of irradiated uranium oxide were emitted from the Windscale Piles. The particles were large compared with most ambient aerosols, 85% by weight being between 10 and 100 micron diameter, and they mostly fell within a few kilometers of the works. From measurements of activity in soil in 1958 onwards, it is estimated that about 12 kg of uranium, 20 Ci of 137Cs, 18 Ci of 90Sr and 0.3 Ci of 239+240Pu were emitted. To estimate the concentrations of 90Sr and 137Cs in milk during the emissions, comparison is made with the fallout of fission products from bomb tests, which also began in 1954, but continued longer. It is calculated that the average level of 90Sr in milk at Seascale, 1954-7, was 36 pCi per g Ca, with higher concentrations, 100-200 pCi (g Ca)-1, in milk from farms immediately surrounding the Windscale plant. For comparison, in 1963/5 the average level of 90Sr in milk in the UK was 20-30 pCi (g Ca)-1, with 90-170 pCi (g Ca)-1 in milk from certain hill farms. Since the oxide particles were larger than those derived from bomb tests, and the conditions of deposition different, an extended review is given (Appendix 1) of the factors determining the entry of radioactive or stable contaminants from fallout into food chains. It is concluded that the oxide particles would have been less efficient in this respect than bomb fallout, mainly because their relatively large size and high density would have given impact velocities sufficient to cause them to bounce off leaves, leaving little activity on the edible herbage. For this reason, the calculations are on the safe side.

A critical review of food fiber analysis and data.

Epidemiologists, research scientists, and dietitians need data on the dietary fiber content of foods. This article provides a provisional table on dietary fiber, compiled after a thorough search of the literature and a critical evaluation of the analytical methodology employed. To make fully understandable the limitations and problems associated with the current dietary fiber data base, a short review of what is meant by the term dietary fiber and the complex chemical structures of the major dietary fibers--cellulose, hemicellulose, pectin, and lignin--are presented. A short description of the numerous analytical methods for quantifying dietary fiber, including the neutral detergent fiber procedure, the various enzymatic gravimetric procedures, and the analytic schemes for measuring the major dietary fiber fractions is also given, along with the strengths and weakness of the various procedures. The table on foods commonly eaten in the United States is meant as an interim guide for menu planning and dietary evaluation until newer data become available. Data are most limited on legumes and the numerous specialty baked products and breads available in this country.