Caramel color safety - An update.

Caramel color has been used in foods and beverages for over 150 years and is globally regulated as a color additive. The four distinct classes of caramel color (Plain Caramel, Sulfite Caramel, Ammonia Caramel, and Sulfite Ammonia Caramel) are well characterized and each have specifications that take into account processing variables including reactants that can give rise to low molecular weight constituents (e.g.

Evaluation of the developmental toxicity of caffeine and caffeine metabolites using the frog embryo teratogenesis assay--Xenopus (FETAX).

The developmental toxicities of caffeine and 13 metabolites, including theophylline, and paraxanthine and a synthetic methylxanthine analogue 3-isobutyl-methylxanthine (IBMX) were evaluated using the Frog Embryo Teratogenesis Assay Xenopus (FETAX). Young X. laevis embryos were exposed to these compounds in each of two separate concentration-response experiments with and without an exogenous metabolic activation system (MAS).

A parallelogram approach for safety evaluation of ingested acetaldehyde.

Route-specific carcinogenicity data are often lacking for compounds of regulatory importance. Acetaldehyde (AA), for example, a natural constituent in foods, is a rodent carcinogen via the inhalation route, but oral carcinogenicity data are not available. In the absence of such data, a parallelogram approach can be used to estimate the oral carcinogenic potency of this chemical.

An immunotoxicity assessment of food flavouring ingredients.

A rapid screening protocol incorporating key elements of the US National Toxicology Program's immunotoxicity tier testing strategy was used to evaluate the effects of 35 commonly used food flavouring ingredients on humoral and cell-mediated immune responses. The test compounds were administered intragastrically on a daily basis for 5 days at three dose levels to female CD-1 or B6C3F1 mice, 6-8 wk old. A host resistance assay (Listeria monocytogenes bacterial challenge) was conducted to assess cell-mediated immunity.

Evidence for genetic basis of seasonal differences in antibody formation between two mouse strains.

In order to confirm the presence of an acrophase difference based upon genotype in the seasonal expression of an immune competence end point, splenic plaque-forming cell (PFC) response to sheep red blood cells (SRBC), female B6C3F1 and CD1 mice were concurrently studied for PFC response during two studies performed in each season for 1 year. Mice were multiply housed, fed ad libitum, and standardized to light (06:00-18:00); dark (18:00-06:00). For each strain and study, subgroups were either naive (n = 10), received a vehicle (n = 10) or Cytoxan (n = 5).

Developmental toxicity evaluation of inhaled citral in Sprague-Dawley rats.

Citral is a commonly used fragrance and flavour ingredient that has demonstrated a potential for teratogenicity in chick embryo screening studies. To investigate potential mammalian developmental toxicity, pregnant Sprague-Dawley rats were exposed to citral by inhalation for 6 hr/day on gestation days 6-15 at mean concentrations of 0, 10 or 34 ppm as vapour, or 68 ppm as an aerosol/vapour mixture. Dams were killed on gestation day 20 and the foetuses were removed and evaluated for gross, visceral and skeletal malformations.

Reproducibility of seasonal effects in antibody formation and host resistance in the outbred mouse.

The purpose of this study was to assess the reproducibility of any seasonal effects in the outbred CD1 mouse of antibody production to sheep red blood cells (SRBCs) and host resistance to the bacterium Listeria monocytogenes. A marked seasonal effect on antibody production was seen when 5- to 6-week-old female CD1 mice were studied on a weekly basis for a period of 2 years. Maintained on a 12:12 h light:dark schedule, animals were held for 12 days prior to experiment to insure physical condition and acclimatization to the lighting regimen.

Effect of repeated exposures to nitrogen dioxide and sulfuric acid mist alone or in combination on mucociliary clearance from the lungs of rabbits.

The biological response to ambient air pollution may be a function of specific combinations of pollutants. Groups of rabbits were exposed to NO2 (0.3 ppm or 1 ppm) with and without H2SO4 (0.

Acute and subchronic ozone inhalation in the rabbit: response of alveolar macrophages.

Ozone is a potent oxidant gas and a common constituent of photochemical smog. This investigation evaluated the numbers and functional capabilities of alveolar macrophages (AM) recovered from rabbits undergoing acute and subchronic ozone exposure. Bronchoalveolar lavage was performed immediately, 24 h, and 7 d after acute (2-h) exposure to 0.

Early alveolar clearance of particles in rabbits undergoing acute and subchronic exposure to ozone.

The concentration-response relationship for changes in early alveolar clearance resulting from O3 inhalation were investigated. Groups of five rabbits were exposed to 0.0, 0.

Measurement of particle clearance from the alveolar region of the rabbit respiratory tract.

This paper describes a method for the measurement of the clearance of inert, insoluble radioactively tagged tracer particles from the alveolar region of the rabbit respiratory tract. The technique uses a fixed detector for noninvasive, external monitoring. Validation of the method is presented, as is the clearance pattern of 3.

Changes in early alveolar particle clearance due to single and repeated nitrogen dioxide exposures in the rabbit.

To better understand the potential health risks associated with short-term NO2 exposures, a study was conducted to examine the effects of single and repeated NO2 exposures on the clearance of inert tracer particles from the alveolar region of rabbit lungs. Single 2-h exposures to 0.3, 1.

Measurement of respiratory tract ammonia in the rabbit and implications to sulfuric acid inhalation studies.

Ammonia (NH3) in the respiratory tract has the potential to neutralize inhaled acid vapors and aerosols. Levels of exhaled (nasal) NH3 were measured in rabbits at different times on the same day, on different days, and in rabbits in a normal fed state, or in a fasted or fed state in which the teeth were brushed and the mouth cleansed. The variability of NH3 levels within any individual rabbit was found to be of the same order as the variability found between different animals.