The sorption of selected polychlorinated biphenyl (PCB) congeners (from tri to deca chlorinated) by three food-packaging plastic films [polyethylene, polyvinyl chloride (PVC), and polystyrene] from an aqueous solution was investigated. From the data generated, PCB uptake, partition, and diffusion coefficients were calculated for the various films. Polyethylene exhibited the highest PCB uptake, diffusion, and partition coefficients when compared to the other materials.
View Article and Find Full Text PDFThe objective of the present study was to determine the degradation products of mancozeb and ethylenethiourea (ETU) and elucidate the possible degradation pathways in solution as a result of chemical oxidation using ozone and chlorine dioxide. This study was developed in a solution at 100 ppm of mancozeb and ETU concentration over the course of 60 min. Two different oxidizing agents used in this study were (1) ozone at 3 ppm and (2) chlorine dioxide at 20 ppm.
View Article and Find Full Text PDFCalcium hypochlorite (Ca(OCl)(2)) and chlorine dioxide (ClO(2)), common disinfecting and bleaching chemicals used in the food industry, are potent oxidizing agents. In this paper, the degradation effects of chlorine dioxide on mancozeb and ethylenethiourea (ETU) residues were investigated in a model system and compared with those of liquid chlorine, under various conditions such as differing concentration, pH, reaction time, and temperature. All samples were analyzed for residues by GLC and HPLC.
View Article and Find Full Text PDFJ Agric Food Chem
November 2001
Laboratory studies were conducted in a model system to determine the effects of ozone (1 and 3 ppm) and hydrogen peroxyacetic acid (HPA) (5 and 50 ppm) at pH 4.6, 7.0, and 10.
View Article and Find Full Text PDFThe objective of this study was to determine the effectiveness of chlorine, chlorine dioxide, ozone, and hydrogen peroxyacetic acid (HPA) treatments on the degradation of mancozeb and ethylenethiourea (ETU) in apples. This study was based on model experiments at neutral pH and temperature. Fresh apples were treated with two different levels of mancozeb (1 and 10 microg/mL).
View Article and Find Full Text PDFMcIntosh, Red Delicious, and Golden Delicious from two years of experimental spray programs using azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl were processed into frozen apple slices, applesauce, single-strength juice, and juice concentrate. Residue levels were expressed as micrograms per 150 g of apple or the equivalent amount of apple product to calculate the percentage change in these pesticides brought about by processing. Producing single-strength apple juice reduced azinphos-methyl, chlorpyrifos, esfenvalerate, and methomyl residues by 97.
View Article and Find Full Text PDFThis chapter presents information on the levels of environmental contaminants found in recent market basket surveys as well as the effect of processing and cooking on the reduction of these contaminants. Although consumers have expressed concern over the level of environmental contaminants in the food supply, market basket surveys involving over 8,000 analyses of foods ready-to-eat, found measurable amounts (ppb levels) of PCBs in only 24 foods. Processing/cooking has been shown to reduce PCBs by 20-100%.
View Article and Find Full Text PDFConcentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were measured in dorsal muscle and eggs of coho salmon, lake trout, and chinook salmon collected from Lakes Superior, Michigan, and Huron (Michigan waters). Absolute and relative concentrations of PCDDs and PCDFs varied among sampling locations (inter- and intralake) and fish species. Fish collected from Bay City (Saginaw Bay) contained the greatest concentrations of PCDDs and PCDFs both in muscle and eggs.
View Article and Find Full Text PDFConcentrations of PCBs, DDTs, toxaphene, chlordanes, dieldrin, and mercury were determined in smallmouth bass (Micropterus dolomieui) collected from Fumee Lake, a remote lake in the Upper Peninsula of Michigan. An ecological hazard assessment was conducted to determine potential impacts of contaminants on bald eagles and mink eating fish from this lake. Concentrations of organochlorines, except toxaphene, and mercury in smallmouth bass were similar to those found in fish from Lake Superior, where atmospheric inputs are the primary sources.
View Article and Find Full Text PDFBull Environ Contam Toxicol
January 1997
J Environ Sci Health B
March 1996
Water and fish samples were collected from selected rivers and lagoons from Côte d'Ivoire. Water samples were analyzed for their chemical characteristics and for the levels of heavy metals and organochlorine pesticides. Fish samples were analyzed for the presence of organochlorine pesticides.
View Article and Find Full Text PDFDeposition of malathion and permethrin onto grass surfaces, after ultra-low volume (ULV) application, was studied in a suburban neighborhood in Saginaw County, Michigan. Commercial concentrates of malathion (Cythion ULV) and permethrin (Biomist 4 + 12) were sprayed using a truck-mounted ULV aerosol generator. Sod-grass blocks (0.
View Article and Find Full Text PDFBull Environ Contam Toxicol
August 1995
Ecotoxicol Environ Saf
August 1993
The assessment of contaminated sediments is a difficult task due to the complex nature of the sediment matrix and the potential for exposure of aquatic organisms to in-place contaminants via several routes. Differential species sensitivity also precludes the completion of a meaningful environmental assessment with only one species. Therefore, a battery of assays approach with the Microtox assay, 48 hr Daphnia magna and Ceriodaphnia dubia tests and a 10-day Chironomous tentans test was used to evaluate the toxicity of sediment pore waters and whole sediments from the Grand Calumet River-Indiana Harbor, Indiana area of concern.
View Article and Find Full Text PDFProcessing conditions were chosen to determine the influence of temperature, pH, and processing on model solutions containing daminozide residues. Daminozide (succinamic acid 2, 2-dimethylhydrazide) fortified solutions (12.5 ppm) containing 50mM NaHPO and 24% sucrose (w/w) were adjusted to pH 3.
View Article and Find Full Text PDFBreakfast consumption patterns of the U.S. adult population were examined by using the U.
View Article and Find Full Text PDFJ Am Diet Assoc
August 1985
Microwave ovens are widely used in foodservice establishments; currently, they are used primarily for reheating. In comparison with conventional methods, approximately 75% less energy is required for microwave cooking or heating. In the future, it is possible that minimal microwave energy will be used to extend shelf life of foods.
View Article and Find Full Text PDFMicrowave-oven technology has been improved by the use of low power. With the utilization of low-power techniques, studies showed equal or better retention of nutrients for microwave, as compared with conventional, reheated foods for thiamin, riboflavin, pyridoxine, folacin, and ascorbic acid. Beef roasts microwaved at "simmer" were comparable with conventionally cooked roasts in sensory quality, while vegetables cooked by an institutional (1,150 w) microwave oven were superior to those cooked in a domestic (550 w) microwave oven.
View Article and Find Full Text PDFThe USDA's 1977-1978 Nationwide Food Consumption Survey was utilized to assess dietary intake levels of cholesterol, fatty acids, sodium, and potassium by several age/sex groups of the U.S. population.
View Article and Find Full Text PDFDietary intake levels of calcium and magnesium, as well as calcium/magnesium ratios, were assessed for 12 age/sex groups of the U.S. population through use of USDA's 1977-78 Nationwide Food Consumption Survey.
View Article and Find Full Text PDFFrom 7-day food diaries of a cross-sectional sample of American elderly individuals (n = 561), breakfast consumption patterns were assessed and related to average daily nutrient intake patterns. Results indicated that, in general, breakfast consumption made a significant contribution to the average elderly individual's daily nutrient intake and, in particular, breakfasts containing ready-to-eat cereal had a greater impact on nutrient intake levels than did breakfasts not containing ready-to-eat cereal. More specifically, elderly individuals who had ready-to-eat cereal at breakfast 4-7 times during the week surveyed consumed significantly less (P less than or equal to 0.
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