Pyrolysis GLC identification of food and drug ingredients. I. Saccharin

Pyrolysis gas-liquid chromatography, used in the qualitative analysis of saccharin, has provided reproducible pyrograms which permit direct characterization of these sweetners in a variety of commerical saccharin tablets and diet beverages. This method was used also to identify the salt, after conversion to the free imide, in a commercial multivitamin product. The tablet analysis required isolation by solvent extraction. Analyses were carried out on quantities ranging from 1 to 100 mug. The sensitivity of the method could be increased by addition of a pure sample of the compound sought to the unknown.

A method for qualitative identification of sugars and semiquantitative determination of lactose content suitable for a variety of foods

A semiquantitative chromatographic technique was developed and standardized using water/chloroform extracts of foods which are spotted onto heat-activated silica gel thin layer chromatographic (TLC) plates, run in butanol/acetic acid/ether/water, developed in acids anisaldehyde, and quantitated planimetrically using Purdy and Truter's formula. Clinically significant amounts of lactose were found in low-calorie sweeteners, breads, yogurt, margarine, penicillin, Gantrisin, and other commonly ingested nondairy substances.

Lead in the environment: sources of danger

Images

[Polarografic determination of saccharin in beverages and foods (author's transl)]

A method for polarografic determination of saccharin in beverages and foods is described. Saccharin is extracted from an acid medium, after clean up with petr. ether, with aether-petr. aether (30/70). Minimum doses which can be quantitatively determined are 5 ppm of saccharin.

Pesticide residues in total diet samples (IX)

During the ninth year of the Total Diet Study, pesticide residues remained at the relatively low levels reported previously. Thirty market baskets were collected in 30 cities which ranged in population from less than 50,000 to 1,000,000 or more. Averages and ranges of residues found are reported for the period August 1972 through July 1973 by food class. Lead, selenium, and zinc data are included for the first time. During this period, the individual items used in making up the dairy and meat composites in four market baskets were analyzed for pesticides and the results are included. Results of recovery studies within various classes of residues are also presented.

Caffeine content of beverages as consumed

Quantitative analysis of beverages prepared at home by staff of the Addiction Research Foundation revealed a lower and much more variable caffeine content of both tea and coffee than had been reported in earlier studies, most of which were based on analysis of laboratory-prepared beverages. Median caffeine concentration of 37 home-prepared samples of tea was 27 mg per cup (range, 8 to 91 mg); for 46 coffee samples the median concentration was 74 mg per cup (range, 29 to 176 mg). If tea and coffee as drunk contain less caffeine than generally supposed, the potency of caffeine may be greater than commonly realized, as may the relative caffeine content of certain commercial preparations, including chocolate and colas. The substantial variation in caffeine content emphasizes the need to establish actual caffeine intake in clinical, epidemiologic and experimental investigations of caffeine effects.

Pesticide residues in total diet samples (VIII)

During the eighth year of the Total Diet Study, residues remained at the relatively low levels reported previously. A total of 35 market baskets were collected in 32 cities which ranged in population from less than 50,000 to 1,000,000 or more. Averages and ranges of residues found are reported for the period June 1971 through July 1972 by region and food class. Results of recovery studies within various classes of residues are also presented.

[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.

Microbiological assay of patulin, using Bacillus megaterium

Bacillus megaterium NRRL 1368 was found to be sensitive to patulin and a suitable test organism for an accurate, quantitative bioassay of the toxin. The optimum conditions for the test were determined. The response of the organism to patulin was found to be linear between 2 and 80 mug. When compared to thin layer chromatographic and spectrophotometric assay methods, the bioassay was found to be comparable in accuracy, but less sensitive. The test was found to be sensitive to 1.7 mug patulin. The assay is rapid (12-15 hr), simple, and inexpensive and can be used to verify the toxicity of samples, as well as to quantitatively measure patulin in samples of liquid media, apple juice, and corn.

A specific method for the determination of provitamin A carotenoids in orange juice

A method has been developed for rapidly determining the amounts of alpha-carotene, beta-carotene, and cryptoxanthin in orange juice. The procedure includes extraction, saponification, and high-speed liquid chromatography. Limits of detection for the 3 carotenoids are 0.04, 0.02, and 0.04 mug/ml, respectively.

[Alterations caused by yeasts in vegetable flavoured soft drinks: effects of the manufacturing water (author's transl)]

Possible sources of yeast pollutions of soft drinks added with vegetable flavours and the factors affecting their magnitude were examined. The greatest role is played by the minerals contained in the manufacturing water. Pasteurization is the most useful practice for their control.

[Simplification of the dinitrophenylhydrazine method for the photometric determination of ascorbic acid and dehydroascorbic acid in fruit juices. I. Application to juice of black current (author's transl)]

The photometric determination of ascorbic acid and dehydroascorbic acid by preparing the 2,4-dinitrophenylhydrazone derivative of dehydroascorbic acid and purifying it by thinlayerchromatography was simplified and adapted to the microliter system of Eppendorf Gerätebau, Hamburg, Germany. Using this method with juice of black current, quite reproducible results for vitamin C contents were obtained. Compared with the method of the International Federation of Fruit Juice Producers (titration with 2,6-dichlorphenolindophenol) the contents of vitamin C found with nine different commercial juices of black current were lower from 13 to 30%.

Provisional tables on the zinc content of foods

A critical and exhaustive review of published and unpublished data on the zinc content of foods showed that, with few exceptions, the major dietary sources of zinc were foods of animal origin. Oysters, which contained more than 5 mg. zinc per 3-oz. cooked portion, were an outstanding source of zinc. Lean beef and beef liver were also among the foods highest in zinc and ground beef was a good source. Dark meat of poultry contained more zinc than light meat, and turkey was higher in zinc than chicken. Egg yolk, but not egg white, was relatively high in zinc, as were nonfat dry milk and Cheddar cheese. Foods of plant origin, like those of animal origin, varied widely in zinc content. Cocoa and the milling fractions of bran and germ of wheat were high in zinc. Seeds of plants, such as muture dry legumes and peanuts, were better sources of zinc than were leaves, stalks, fruits, or roots. Vegetables, fruits, oils, fats, tea, coffee, and carbonated beverages contained little zinc. Factors influencing the zinc content of foods were evaluated. Provisional tables, giving representative values for zinc in more than two hundred foods, both in 100-gm. portions and in common household units, based on this research, are presented.

Degrees of saturation with respect to apatites in fruit juices and acidic drinks

Some fruit juices and carbonated acidic drinks, recognized as agents causing dental erosions, were analyzed for calcium, phosphate, fluoride and pH. Ionic activity/concentration products for hydroxyapatite and fluorapatite were calculated. It was found that all liquids analyzed were unsaturated with respect to both apatites, which explains their erosive effect.

Aluminum in the environment and human health

The review of over 800 references on aluminum (Al) published since the mid-fifties covers the occurrence of Al in soil, air, water, plants and food products, as well as air and water pollution problems. In addition, the existing quality criteria, the biology and toxicology of Al, and the therapeutic and medical uses are presented. It is concluded that absorption and retention or accumulation of Al in humans occurs at lower levels of intake than had been assumed formerly. However, levels of 5 to 50 times the normal daily intake do not appear to interfere with other metabolic processes. The adverse effects of Al reported in the more recent years resulted from the inhalation or ingestion of Al in concentrations many times greater than the amounts present under normal circumstances. As in the past, there is still no need for concern by the public or producers of Al or its products concerning hazards to human health derived from well established and extensively used products.