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A novel approach is developed to establish safety levels for organophosphate pesticides residues present in 80 fruit, vegetable, and nut commodities. These levels, known as Pesticide Safety Levels (PSL), represent the concentration of the organophosphate pesticide residue that would be required to cause daily exposure of the highest-consuming population subgroup at the 95th percentile of consumption (based upon US food consumption estimates) to reach the adjusted acute reference dose of the pesticide. A total of 4,320 PSLs were developed for 54 organophosphate pesticides on the 80 commodities. Comparisons of PSLs and tolerances and/or MRLs, when available, indicated that only a small percentage of PSLs were lower than or equal to regulatory levels (1.9% below/equal to tolerance levels and 2.3% below/equal to Codex MRLs). In the pesticide/commodity combinations where PSLs were below tolerances and/or MRLs, monitoring results indicated that the maximum residues of organophosphate pesticides on the commodities were far below both the PSL and tolerance/MRL values. In most cases, PSLs were much higher than existing tolerances and/or MRLs. PSLs were at least 100 times higher than tolerances in 50.1% of the comparisons and at least 100 times higher than MRLs 64.1% of the time. PSLs were at least ten times higher than tolerances 75.8% of the time and at least ten times higher than MRLs 82.8% of the time. PSLs serve a useful role in determining the health significance, if any, in the event that residues of organophosphate pesticides exceed existing tolerances and/or MRLs as well as in cases where residues of organophosphate pesticides are detected on commodities for which no tolerance or MRL has been established. PSLs can also be used to customize pesticide residue monitoring programs to focus more on consumer safety than on good agricultural practices.

Existing methods for the analysis of pesticides in human breast milk involve multiple extraction steps requiring large sample and solvent volumes, which can be a major obstacle in large epidemiologic studies. Here, we developed a simple, low-volume method for extracting organophosphates, pyrethroids, carbamates, atrazine, and imidacloprid from 100 to 200 μL of human breast milk. Multiple extraction protocols were tested including microwave-assisted acid/base digestion and double-solvent extraction with 2 or 20 mL of 2:1 (v/v) dichloromethane/hexane, with or without subsequent solid-phase extraction (SPE) cleanup. Samples were analyzed by liquid chromatography tandem mass spectrometry. Analyte recoveries and reproducibility were highest when 100-200 μL of milk were extracted with 2 mL of dichloromethane/hexane without subsequent SPE steps. Analysis of 79 breast milk samples using this method revealed the presence of carbamates, organophosphates, pyrethroids, and imidacloprid at detection frequencies of 79-96, 53-90, 1-7, and 61%, respectively. This study demonstrates the feasibility of a simple low-volume extraction method for measuring pesticides in human breast milk.

Food fraud, the intentional misrepresentation of the true identity of a food product or ingredient for economic gain, is a threat to consumer confidence and public health and has received increased attention from both regulators and the food industry. Following updates to food safety certification standards and publication of new U.S. regulatory requirements, we undertook a project to (i) develop a scheme to classify food fraud-related adulterants based on their potential health hazard and (ii) apply this scheme to the adulterants in a database of 2,970 food fraud records. The classification scheme was developed by a panel of experts in food safety and toxicology from the food industry, academia, and the U.S. Food and Drug Administration. Categories and subcategories were created through an iterative process of proposal, review, and validation using a subset of substances known to be associated with the fraudulent adulteration of foods. Once developed, the scheme was applied to the adulterants in the database. The resulting scheme included three broad categories: 1, potentially hazardous adulterants; 2, adulterants that are unlikely to be hazardous; and 3, unclassifiable adulterants. Categories 1 and 2 consisted of seven subcategories intended to further define the range of hazard potential for adulterants. Application of the scheme to the 1,294 adulterants in the database resulted in 45% of adulterants classified in category 1 (potentially hazardous). Twenty-seven percent of the 1,294 adulterants had a history of causing consumer illness or death, were associated with safety-related regulatory action, or were classified as allergens. These results reinforce the importance of including a consideration of food fraud-related adulterants in food safety systems. This classification scheme supports food fraud mitigation efforts and hazard identification as required in the U.S. Food Safety Modernization Act Preventive Controls Rules.

While the need to present food science information effectively is viewed as a critical competency for food scientists by the Institute of Food Technologists, most food scientists may not receive adequate training in this area. Effective presentations combine both scientific content and delivery mechanisms that demonstrate presenter enthusiasm for the topic and generate audience interest. This paper provides food science presentation “best practices” based upon the results of the author's 10 y of experience teaching communication skills to 1st-year graduate students. Topics include development of a “Presentation Inventory” that encourages presenters to consider why they are presenting, who they are presenting to, what information they plan to present, and how they plan to present the information. More specific sections of the paper address presentation introductions and conclusions, developing visual aids, responding to audience questions, flow, pacing, and time management, technological competency, and tips on how to practice a presentation. Such information should be applicable to all types of food science practitioners including undergraduate and graduate students, postdoctoral scholars, teaching and research academics, and government, industrial, and consulting food scientists. An awareness of such “best practices” among presenters of food science information can help raise the bar to improve the quality of contemporary food science presentations.

Allowable levels for pesticide residues in foods, known as tolerances in the US and as maximum residue limits (MRLs) in much of the world, are widely yet inappropriately perceived as levels of safety concern. A novel approach to develop scientifically defensible levels of safety concern is presented and an example to determine acute and chronic pesticide food safety standard (PFSS) levels for the fungicide captan on strawberries is provided. Using this approach, the chronic PFSS level for captan on strawberries was determined to be 2 000 mg kg−1 and the acute PFSS level was determined to be 250 mg kg−1. Both levels are far above the existing tolerance and MRLs that commonly range from 3 to 20 mg kg−1, and provide evidence that captan residues detected at levels greater than the tolerance or MRLs are not of acute or chronic health concern even though they represent violative residues. The benefits of developing the PFSS approach to serve as a companion to existing tolerances/MRLs include a greater understanding concerning the health significance, if any, from exposure to violative pesticide residues. In addition, the PFSS approach can be universally applied to all potential pesticide residues on all food commodities, can be modified by specific jurisdictions to take into account differences in food consumption practices, and can help prioritize food residue monitoring by identifying the pesticide/commodity combinations of the greatest potential food safety concern and guiding development of field level analytical methods to detect pesticide residues on prioritized pesticide/commodity combinations.

Diacetyl, noted for its appealing butter-like aroma, is present naturally in many foods, and humans have been exposed to it since the beginning of civilization. The advent of microwave (MW) cooking technology has led to the development of a significant market for MW popcorn, to which diacetyl and other flavoring compounds have been frequently added. Based upon reported associations between diacetyl inhalation and lung disease in employees of MW popcorn processing facilities, a very conservative safe level of occupational exposure to diacetyl has been proposed by the American Conference of Governmental Industrial Hygienists. Yet there is conflicting evidence that diacetyl causes lung disease in workers, and no evidence to condemn diacetyl as the cause of lung problems in MW popcorn consumers. Consumer dietary exposure to diacetyl in foods is below levels of health concern while common airborne levels of diacetyl from MW popcorn are far below the conservatively established limit to protect workers.

This chapter discusses the broad topic of pesticide residues in food supply. Attention is given to pesticide use patterns and regulation (international and United States) of pesticides. Pesticide residue data are provided from a variety of monitoring programs, and the potential risks posed by pesticide residues are discussed. Consideration is given to the special topics of pesticides in imported foods and pesticides in organic foods.

The article of record as published may be found at http://dx.doi.org/10.1016/j.fct.2011.11.006 Western and guideline based diets were compared to determine if dietary improvements resulting from following dietary guidelines reduce acrylamide intake. Acrylamide forms in heat treated foods and is a human neurotoxin and animal carcinogen. Acrylamide intake from the Western diet was estimated with probabilistic techniques using teenage (13–19 years) National Health and Nutrition Examination Survey (NHANES) food consumption estimates combined with FDA data on the levels of acrylamide in a large number of foods. Guideline based diets were derived from NHANES data using linear programming techniques to comport to recommendations from the Dietary Guidelines for Americans, 2005. Whereas the guideline based diets were more properly balanced and rich in consumption of fruits, vegetables, and other dietary components than the Western diets, acrylamide intake (mean ± SE) was significantly greater (P < 0.001) from consumption of the guideline based diets (0.508 ± 0.003 lg/kg/day) than from consumption of the Western diets (0.441 ± 0.003 lg/kg/day). Guideline based diets contained less acrylamide contributed by French fries and potato chips than Western diets. Overall acrylamide intake, however, was higher in guideline based diets as a result of more frequent breakfast cereal intake. This is believed to be the first example of a risk assessment that combines probabilistic techniques with linear programming and results demonstrate that linear programming techniques can be used to model specific diets for the assessment of toxicological and nutritional dietary components. Approved for public release; distribution is unlimited.

article i nfo Article history: Received 15 February 2011 Accepted 31 May 2011 Salmonellosis outbreaks from consumption of raw almonds in 2001 and 2004 led to regulations that require mandatory treatment of almonds sold in North America to give a minimum 4-log reduction of Salmonella .T his study aims to: 1) assess the risk of salmonellosis associated with almond consumption in North America, with currenttreatmentsineffect;2)determinetheresilienceofthecurrentproductionsystemtoincreasesinprevalence or concentration of Salmonella on almonds; 3) assess the impact of treating less than 100% of the crop; and 4) investigate conditions that could explain the number of cases associated with the 2001 outbreak. Risk was assessed using a Monte Carlo simulation, based on an established dose-response relationship. Data for almond amounts sold, Salmonella prevalence and concentration on almonds, storage time and temperature at different handling steps, population reductions during storage at various temperatures and with different treatments, and consumer handling were based on data from published sources and almond industry or academic expert opinion. What-if scenarios were evaluated for Salmonella prevalence varying from 1 to 65%, concentrations of Salmonella varyingfrom 1to 120 MPN/100 g,and portionsofuntreated cropvaryingfrom 0to 10%.Theestimated incidenceof salmonellosis in North America from almonds as currently treated is on average 0.008 cases per billion servings (with an estimated 6.6 billion servings consumed annually). Increases in Salmonella prevalence to 25%, mean concentrations above 25 MPN/100 g, or leaving 0.05% of the crop untreated all resulted in an arithmetic mean risk greater than 1 case/year (with geometric means remaining below 1 case/year for all variables). Assuming 4000 kg at a prevalence of 65% (observed in recalled lots) and an average concentration of 120 MPN/100 g in raw almonds (back calculated from levels in recalled almonds) predicted over the 2800 cases estimated for the 2001 outbreak. Applying a 4-log reduction to these almonds reduced the average number of predicted cases to less than a single case. The current regulation is effective in maintaining the risk of salmonellosis from consumption of almonds below an arithmetic mean of 1 case/year, although significant increases in either prevalence or concentration, or small increases in proportion of untreated almonds would frequently lead to exceeding this threshold.

Probabilistic techniques were used to characterize dietary exposure of consumers to pesticides found in twelve commodities implicated as having the greatest potential for pesticide residue contamination by a United States-based environmental advocacy group. Estimates of exposures were derived for the ten most frequently detected pesticide residues on each of the twelve commodities based upon residue findings from the United States Department of Agriculture's Pesticide Data Program. All pesticide exposure estimates were well below established chronic reference doses (RfDs). Only one of the 120 exposure estimates exceeded 1% of the RfD (methamidophos on bell peppers at 2% of the RfD), and only seven exposure estimates (5.8 percent) exceeded 0.1% of the RfD. Three quarters of the pesticide/commodity combinations demonstrated exposure estimates below 0.01% of the RfD (corresponding to exposures one million times below chronic No Observable Adverse Effect Levels from animal toxicology studies), and 40.8% had exposure estimates below 0.001% of the RfD. It is concluded that (1) exposures to the most commonly detected pesticides on the twelve commodities pose negligible risks to consumers, (2) substitution of organic forms of the twelve commodities for conventional forms does not result in any appreciable reduction of consumer risks, and (3) the methodology used by the environmental advocacy group to rank commodities with respect to pesticide risks lacks scientific credibility.

A quantitative microbial risk assessment was constructed to determine consumer risk from Staphylococcus aureus and staphylococcal enterotoxin in raw milk. A Monte Carlo simulation model was developed to assess the risk from raw milk consumption using data on levels of S. aureus in milk collected by the University of California-Davis Dairy Food Safety Laboratory from 2,336 California dairies from 2005 to 2008 and using U.S. milk consumption data from the National Health and Nutrition Examination Survey of 2003 and 2004. Four modules were constructed to simulate pathogen growth and staphylococcal enterotoxin A production scenarios to quantify consumer risk levels under various time and temperature storage conditions. The three growth modules predicted that S. aureus levels could surpass the 10(5) CFU/ml level of concern at the 99.9th or 99.99th percentile of servings and therefore may represent a potential consumer risk. Results obtained from the staphylococcal enterotoxin A production module predicted that exposure at the 99.99th percentile could represent a dose capable of eliciting staphylococcal enterotoxin intoxication in all consumer age groups. This study illustrates the utility of quantitative microbial risk assessments for identifying potential food safety issues.

Musical parodies of contemporary songs withtheir lyrics altered to address current food safety issues wereincorporated into a variety offood safety educational programs and the effectiveness of the music was evaluated by semiquantitative and qualitative measures. Audiences receivingthe music-enriched curriculaincluded schoolfoodservice supervisors,schoolfoodservice managers, culinary arts instructors,culinary arts students, Family and Consumer Sciences teachers, and youthaged 8to 12 y and studies wereconducted inSouthCarolina,NorthCarolina,andDelaware. Among school foodservicesupervisors,school foodservicemanagers, and culinary arts students,most participants were able to recall themainpointsofeachsongthatwasintroduced inthe curriculum. The culinary arts students wereless likely to recallthe main points ofeach songthan werethe other 2 groups, possibly becauseof the lack of prior knowledge of food safety practices as wellas alack of preference forthestyleofsongsused.FamilyandConsumer Sciences teachers were enthusiastic about the useof the music but alsoidentified potential barriers to the successfuluse ofthe music,due tothe potential lackof appropriate audiovisual equipment, a lack ofskills inusing such equipment, and time constraints for the useof music incurricula due to the strongemphasis on end ofyear testing. Participants in the summer youthgroups demonstrated significant increases between pre- and posttest examinations of safe food handling behaviors and most were able to quote lines orphrases from the songs.

Discussions as to the extent of pesticide residue contamination in the food supply often rely on results of government residue monitoring programs focusing primarily upon the percentages of samples containing pesticide residues and the number of violative residues identified. Such an approach does not adequately convey the likelihood of pesticide residues posing consumer risks since residue regulatory limits are not safety standards and violative pesticide residues rarely constitute residues of health concern. It is more appropriate to develop estimates of actual dietary exposure to pesticides and to compare such estimates to established toxicological criteria such as the Chronic Reference Dose (RfD). The U.S. Food and Drug Administration’s (FDA) Total Diet Study (TDS) previously provided such information but last published its findings in 1995 to estimate dietary exposure to pesticides detected between 1986 and 1991. This paper provides updated estimates of dietary exposure to pesticides in the United States using the most recent TDS findings on pesticide residues. A total of 77 specific pesticides were detected from market basket samples of 2240 TDS food items analyzed by FDA in 2004 and 2005. All estimated exposures to the 77 pesticides for the General US population were well below chronic RfD levels. Only 3 of the 77 pesticides showed exposures greater than 1 % of chronic RfDs, while 14 showed exposures between 0.1 and 1 % of chronic RfDs and 19 had exposures between 0.01 and 0.1 % of chronic RfDs. The remaining 41 pesticides had exposures below 0.01 % of chronic RfDs. Compared with 1986–1991 findings, dietary exposure to six environmentally persistent chlorinated hydrocarbon insecticides were reduced by factors of 47 to 96 % in 2004–2005. Exposures to 15 different population subgroups were estimated and indicated that children, particularly two year-olds, frequently receive higher exposures to pesticide residues in their diets than do adults. Chronic dietary exposure to pesticides in the diet, according to results of the FDA’s 2004–2005 TDS, continue to be at levels far below those of health concern. Consumers should be encouraged to eat fruits, vegetables, and grains and should not fear the low levels of pesticide residues found in such foods.

Consumers are frequently exposed to arsenic in foods and considerable public and scientific concern exists regarding the potential health risks from dietary arsenic. Arsenic exists in both organic and inorganic forms and health effects are primarily attributed to inorganic forms. The most common analytical methods used to detect arsenic measure total arsenic, which includes both organic and inorganic forms. It is therefore necessary to make assumptions concerning the amounts of total arsenic found in food samples that represent inorganic arsenic. This work presents a new assessment of US dietary exposure to arsenic using data available from the FDA Total Diet Study from 2006-2008 and a series of scenarios developed to estimate inorganic arsenic levels. Total arsenic exposures were estimated for 16 population subgroups and ranged from 1.4 x10-1 to 4.5 x10-1 µg/kg/day. The population subgroup with the highest exposure to total arsenic was 2 year-old children. The major food group contributors to total arsenic exposure for the general US population were marine sources, which accounted for 69 percent of the total arsenic exposure, and grains, legumes and seeds, which accounted for 20 percent. The highest inorganic arsenic exposures occurred for 2 year-old children and ranged from to 1.1 x10-1 µg/kg/day to 2.4 x10-1 µg/kg/day. Inorganic arsenic exposures for the 2 year-olds were 3.3 to 4.8 times higher than inorganic arsenic exposures for the general population. Under Scenario 5, which assumed that 70 percent of total arsenic from terrestrial sources and 10 percent of total arsenic from marine sources existed as inorganic arsenic, the most important food group contributors to inorganic arsenic for 2 years-olds were grains, legumes and seeds (50 percent), beverages (14 percent), marine sources (13 percent) and snacks and breakfast cereals (12 percent). The exposures estimates obtained in this work are below the EPA’s established RfD of 0.3 µg/kg/day for inorganic arsenic and below EFSA’s health concern level of 0.3 to 8.0 µg/kg/day. To improve the accuracy of future arsenic risk assessments, studies should incorporate specific analytical data measuring inorganic arsenic from foods contributing the most to inorganic arsenic exposure.

The biosynthesis of the sphinganine analogue mycotoxins (SAMs) fumonisin B1 and the AAL toxins was studied by growing Fusarium moniliforme and Alternaria alternata f. sp. lycopersici in liquid culture. Radioactive and stable isotopically labeled amino acid, water, and molecular oxygen precursors were added to the culture media and toxins were analyzed using thin-layer chromatography, liquid scintillation counting, high-performance liquid chromatography (HPLC), 13C nuclear magnetic resonance (NMR) spectroscopy, and electrospray mass spectrometry (ESMS). Results indicated that glycine was incorporated directly into the AAL toxins and that methionine was incorporated into the AAL toxin methyl groups. Oxygens in tricarballylic acid moieties for fumonisin B1 and the AAL toxins were derived from H2O while the lipid backbone hydroxyls for fumonisin B1 and the AAL toxins originated from molecular oxygen. Isotopic enrichment patterns for the various AAL toxins showed marked differences among toxins, suggesting a c...

Using trans-diphenylpropane oxide (tDPPO) as a substrate, we measured epoxide hydrolase (EH) activity in subcellular fractions of Alternaria alternata f. sp. lycopersici (Aal), a fungus that produces host-specific toxins. The activity was mainly (>99.5%) located in the soluble fraction (100,000 × g supernatant) with the optimum pH at 7.4. An increase of toxin production between days 3 and 9 found in a Aal liquid culture over a 15 days period was concomitant with a period of high EH activity. EH activity remained constant during the same period in an Alternaria alternata culture, a fungus which does not produce toxin. In vivo treatment of Aal culture with the peroxisome proliferator clofibrate stimulated EH activity by 83% and enhanced toxin production 6.3 fold. Both 4-fluorochalcone oxide (4-FCO) and (2S,3S)-(-)-3-(4-nitrophenyl)-glycidol (SS-NPG) inhibited EH activity in vitro with a IM50f 23 ± 1 μM and 72 ± 19 μM, respectively. The possible physiological substrate 9,10-epoxystearic acid was hydrolyzed more efficiently by Aal sEH than the model substrates trans- and cis-stilbene oxide (TSO and CSO) and trans- and cis-diphenylpropane oxide (tDPPO and cDPPO).

Vitamin A (VA) deficiency causes disability and mortality. Cassava can be crossbred to improve its β-carotene (BC) content; typical white cassava contains negligible amounts of BC. However, cassava contains cyanide and its continued consumption may lead to chronic disability. Our objective was to estimate the risk–benefit of consuming BC-enhanced cassava to increase VA intake. A total of ten American women were fed white and BC-enhanced cassava. BC and cyanide data from the feeding study were combined with African cassava consumption data to model the potential daily BC, VA and cyanide intakes of African women. If BC-enhanced cassava replaced white cassava in the diets, it could theoretically meet recommended VA intakes for the following percentages of individuals from six African countries that consume cassava as a staple crop: Angola (95 %), Central African Republic (95 %), Congo (about 100 %), Ghana (99 %), Mozambique (99 %) and Nigeria (92 %). Cyanide intake after minimal preparation of cassava could be thirteen to thirty-two times the reference dose (RfD), a toxicological exposure reference, but could be completely removed by extensive soaking. This study demonstrates that consumption of BC-enhanced cassava, processed to maintain BC and remove cyanide, theoretically increases VA intakes for African populations and other areas of the world where cassava is a staple crop.

There are a number of chemical contaminants of the food supply that have recently attracted consumer and regulatory interest due to their potential toxicological implications. This article discusses four contaminants – dioxins, acrylamide, perchlorate, and bisphenol A (BPA) and provides information concerning their presence in foods, regulatory efforts, toxicological effects, and potential risks to consumers.

Food safety concerns involving pesticide residues continue to receive widespread public, legislative, and scientific attention. The National Research Council's 1993 report Pesticides in the Diets of Infants and Children concluded that significant improvements in the U.S. government's pesticide risk assessment and food tolerance establishment procedures were needed. Strict interpretation of the Delaney Clause by the U.S. Ninth Circuit Court of Appeals has led to the projected elimination of several pesticide uses due to statutory, rather than scientific considerations. Congressional "solutions" to the Delaney problem may have broad impacts upon future pest management practices if adopted. Emerging issues include the safety of imported produce and the potential effects of trade agreements such as NAFTA and GATT upon U.S. pesticide residue standards. Additional index words: Delaney Clause, food safety, GATT, NAFTA, pesticide residues, risk assessment, tolerances.

The ionization and differentation behavior of two groups of sphinganine analog mycotoxins (SAMs), the AAL toxins (TA, TB, TC, TD, and TE) and fumonisins (FB 1 and FB 2 ), were compared in positive and negative electrospray ionization (ESI) modes. Toxins containing amino groups yielded abundant [M+H] + in positive mode, whereas N-acetylated town congeners were protonated less efficiently but yielded abundant [M+Na] + ions. Negative ESI mass spectra exhibited abundant [M-H] - ions for all towns, and fumonisins could be distinguished by the presence of additional peaks corresponding to [M-2H] 2

Consumers are frequently urged to avoid imported foods as well as specific fruits and vegetables due to health concerns from pesticide residues and are often encouraged to choose organic fruits and vegetables rather than conventional forms. Studies have demonstrated that while organic fruits and vegetables have lower levels of pesticide residues than do conventional fruits and vegetables, pesticide residues are still frequently detected on organic fruits and vegetables; typical dietary consumer exposure to pesticide residues from conventional fruits and vegetables does not appear to be of health significance. Similarly, research does not demonstrate that imported fruits and vegetables pose greater risks from pesticide residues than do domestic fruits and vegetables or that specific fruits and vegetables singled out as being the most highly contaminated by pesticides should be avoided in their conventional forms.

Three new pairs of biologically active regioisomeric toxins (AAL toxins TC, TD, and TE) were isolated from liquid cultures of Alternaria alternata f. sp. lycopersici, purified using standard chromatographic procedures, and their structures elucidated following interpretation of spectra obtained from NMR and mass spectrometry experiments. Each of the toxin congeners is structurally similar to the AAL toxin TA, which was characterized earlier from culture filtrates of this fungus. AAL toxin TC resembles TA but differs in its lack of hydroxyl groups at C 4 and C 5 . AAL toxin TE is the N-acetylated form of TC [...]

Following an investigation of the relationship between pesticide tolerances and safety, it is concluded that pesticide tolerances are not relevant as safety standards. This conclusion is based upon the findings that theoretical exposures to legal levels of pesticides in the diet may pose greater than negligible risks, while exposures to most illegal residues are of no apparent toxicological significance. Thus, the common and logical views that "legal" residues are "safe" while "illegal" residues are "unsafe" are not supported by scientific evidence. Pesticide tolerances do serve important roles as enforcement tools, and tolerance enforcement programs are useful in the regulation of international trade and provide economic disincentives that may discourage pesticide misuse and emphasize compliance with regulations. Since tolerances are not appropriate as safety standards, however, legislative food safety proposals focusing upon revocation or reduction of tolerances and upon increasing enforcement capabilities may result in little benefit to public health.

The levels of natural plant toxins and mycotoxins in foods may be influenced by the methods used (organic vs. conventional) for agricultural production. Research findings suggest that organic foods may possess higher levels of natural plant toxins than conventional foods based upon mechanistic similarities between natural plant toxin production and the production of plant secondary metabolites of nutritional interest. Specific field research confirming such differences has not yet been conducted. Mycotoxin levels in organic foods may also be higher as a few studies have demonstrated that synthetic fungicides and insecticides used in conventional production can reduce plant pathogen populations. Food product analysis, however, has not demonstrated consistent findings of higher levels of mycotoxins in organic foods as compared with conventional foods. In the event that subsequent research does conclusively demonstrate that differences exist in the levels of naturally occurring toxins in organic versus conventional foods, the toxicological significance of the differences, if any, still requires determination.

A large number of chemicals, both natural and synthetic, may enter the food supply and pose potential food safety concerns. Some of these chemicals are intentionally added to food, such as preservatives, colors, and flavors, while others, such as pesticides, metals, veterinary drugs, and food packaging materials, may inadvertently contaminate the food supply. This article gives an overview of the risk assessment and regulation of food contaminants, with specific emphasis on pesticide residues, dioxins, acrylamide, and chemical components in organic foods Keywords: food safety; chemical contaminants; toxins; regulation; risk assessment; pesticides; dioxins; acrylamide; organic foods

Author(s): Winter, Carl K; Gallegos, Lisa K | Abstract: Genetically engineered (GE) food is produced from plants, animals, and microbes that have had their genetic code modified in some way, an approach that has yielded both benefits and consumer safety concerns. This publication answers some basic questions on the GE process and food safety.

This manuscript provides a brief overview of many useful Internet resources concerning food toxicology. Specific topic areas include pesticide residues, food additives, natural toxins, environmental contaminants, and food allergies; numerous links and evaluative information are provided within each topic area. Several helpful Internet resources have been identified and include government, industry, academic, and consumer sites.

AAL toxins and fumonisins comprise a family of highly reactive, chemically related mycotoxins that disrupt cellular homeostasis in both plant and animal tissues. Two critical issues to resolve are the detection of the entire family in food matricies and the mode of cellular disruption. Analysis of the entire set of chemical congeners in food matrices is difficult but has been achieved by a combination of different HPLC and mass spectrometry strategies. The mode of cellular disruption is unknown but likely involves changes associated with the inhibition of ceramide synthase in both plants and animals. Toxin treated cells exhibit morphological and biochemical changes characteristic of apoptosis. Further evaluation of the specific genetic and biochemical changes that occur during toxin-induced cell death may aid in understanding the mole of the action of these mycotoxins.