Occurrence of Ochratoxin A in Infant Foods in the United States

Ochratoxin A (OTA) is a possible human carcinogen and occurs frequently in cereal grain, soy, and other agricultural commodities. Infants and young children may be more susceptible to contaminants than adults because of their lower body weight, higher metabolic rate, reduced ability to detoxify food toxicants, and more restricted diet. The purpose of this study was to investigate the occurrence and levels of OTA in infant formula and infant cereal products available in the U.S. market. In the present study, 98 powdered infant formula (milk- and soy-based) samples and 155 infant cereal (barley-, rice-, oat-, wheat-, and mixed grain-based) products were collected from different retail locations in the United States over a 2-year period. OTA levels were determined by liquid chromatography-tandem mass spectrometry. Although OTA was not detected in any of the infant formula samples, 47 (30%) of 155 infant cereals were contaminated with OTA in the range of 0.6 to 22.1 ng/g. At present, there is no regulatory limit for OTA in the United States. However, all of the positive samples were above the maximum level set by the European Commission (0.5 ng/g) for OTA in baby foods. OTA was detected in all types of infant cereals, but the highest incidence and concentrations were found in oat-based infant cereals (59%), followed by mixed grain cereals (34%). Increased surveillance and monitoring of OTA levels in grains used in infant foods may be needed to reduce exposure of infants and young children to OTA from cereal products.

A risk assessment of dietary Ochratoxin a in the United States

Ochratoxin A (OTA) is a mycotoxin (fungal toxin) found in multiple foodstuffs. Because OTA has been shown to cause kidney disease in multiple animal models, several governmental bodies around the world have set maximum allowable levels of OTA in different foods and beverages. In this study, we conducted the first exposure and risk assessment study of OTA for the United States' population. A variety of commodities from grocery stores across the US were sampled for OTA over a 2-year period. OTA exposure was calculated from the OTA concentrations in foodstuffs and consumption data for different age ranges. We calculated the margin of safety (MOS) for individual age groups across all commodities of interest. Most food and beverage samples were found to have non-detectable OTA; however, some samples of dried fruits, breakfast cereals, infant cereals, and cocoa had detectable OTA. The lifetime MOS in the US population within the upper 95% of consumers of all possible commodities was >1, indicating negligible risk. In the US, OTA exposure is highest in infants and young children who consume large amounts of oat-based cereals. Even without OTA standards in the US, exposures would not be associated with significant risk of adverse effects.

Rapid method for the determination of multiple mycotoxins in wines and beers by LC-MS/MS using a stable isotope dilution assay

A "dilute and shoot" method for the liquid chromatography-tandem mass spectrometric (LC-MS/MS) determination of multiple mycotoxins (aflatoxins B1, B2, G1, G2, ochratoxin A (OTA), fumonisins (F) B1 and B2, zearalenone, deoxynivalenol, T-2 toxin, and HT-2 toxin) in wines and beers has been developed and validated. Separation was accomplished using ultrahigh-performance liquid chromatography (UHPLC) with <10 min analysis time. Mycotoxins were detected by dynamic multiple reaction monitoring (MRM) in positive electrospray ionization mode. Due to matrix effects, (13)C-uniformly labeled mycotoxins were added to the sample extracts prior to LC-MS/MS analysis. With external calibration, recoveries were 18-148% for white wines, 15-118% for red wines, and 20-125% for beers, at three spiking levels. The (13)C-labeled internal standards compensated for matrix effects effectively, with overall recoveries of 94-112% for white wines, 80-137% for red wines, and 61-131% for beers, with greater recoveries for FB1 and FB2, at three spiking levels. The relative standard deviation was <20% for all analytes in the wines and beers. This method was applied to a USDA-funded nationwide survey of domestic and imported wines and beers for the determination of OTA and extended to include other mycotoxins.

Reduction of pesticide residues in tomatoes and other produce

There is interest in reducing pesticide residues in fruits and vegetables in order to minimize human exposure. The objectives of this study were to (i) determine the effect of various washing treatments with and without sonication on pesticide removal from tomatoes and (ii) assess the effectiveness of a water wash on select samples using a produce-washing flume. In the first set of experiments, tomatoes were contaminated with acephate, malathion, carbaryl, bifenthrin, cypermethrin, permethrin, cyhalothrin, chlorothalonil, and imidacloprid and were dried overnight. Subsets of the tomatoes were then washed (10°C, 1 min) with one of the following: water, sodium hypochlorite (80 μg/ml, pH 7), peroxyacetic acid (80 μg/ml), or Tween 20 (0.1%) with and without sonication. In general, the effect of sonication depended on the washing treatment and on the pesticide. A separate experiment measured pesticide residues in contaminated samples before and after being washed in a flume (22°C, 1 min). Pesticide residues in contaminated produce were reduced from about 40 to 90% when washed for 1 min in the flume.

Multiresidue pesticide analysis of dried botanical dietary supplements using an automated dispersive SPE cleanup for QuEChERS and high-performance liquid chromatography-tandem mass spectrometry

An automated dispersive solid phase extraction (dSPE) cleanup procedure as part of the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method, coupled with liquid chromatography-tandem mass spectrometry using electrospray ionization in positive mode, was used for the simultaneous analysis of 236 pesticides in three dried powdered botanical dietary supplements (ginseng, saw palmetto, and gingko biloba). The procedure involved extraction of the dried powdered botanical samples with salt-out acetonitrile/water extraction using anhydrous magnesium sulfate and sodium chloride, followed by an automated dSPE cleanup using a mixture of octadodecyl- (C18) and primary-secondary amine (PSA)-linked silica sorbents and anhydrous MgSO4 and online LC-MS/MS analysis. Dynamic multiple-reaction monitoring (DMRM) based on the collection of two precursor-to-product ion transitions with their retention time windows was used for all of the targeted pesticides and the internal standard. Matrix-matched calibration standards were used for quantitation, and standard calibration curves showed linearity (r(2) > 0.99) across a concentration range of 0.2-400 ng/mL for the majority of the 236 pesticides evaluated in the three botanical matrices. Mean recoveries (average %RSD, n = 4) were 91 (6), 93 (4), 96 (3), and 99 (3)% for ginseng, 101 (9), 98 (6), 99 (4), and 102 (3)% for gingko biloba, and 100 (9), 98 (6), 96 (4), and 96 (3)% for saw palmetto at fortification concentrations of 25, 100, 250, and 500 μg/kg, respectively. The geometric mean matrix-dependent instrument detection limits were 0.17, 0.09, and 0.14 μg/kg on the basis of the studies of 236 pesticides tested in ginseng roots, gingko biloba leaves, and saw palmetto berries, respectively. The method was used to analyze incurred ginseng samples that contained thermally labile pesticides with a concentration range of 2-200 μg/kg, indicating different classes of pesticides are being applied to these botanicals other than the traditional pesticides that are commonly used and analyzed by gas chromatography techniques. The method demonstrates the use of an automated cleanup procedure and the LC-MS/MS detection of multiple pesticide residues in dried, powdered botanical dietary supplements.

Chemical inactivation of protein toxins on food contact surfaces

We compared the kinetics and efficacies of sodium hypochlorite, peracetic acid, phosphoric acid-based detergent, chlorinated alkaline detergent, quaternary ammonium-based sanitizer, and peracetic acid-based sanitizer for inactivating the potential bioterrorism agents ricin and abrin in simple buffers, food slurries (infant formula, peanut butter, and pancake mix), and in dried food residues on stainless steel. The intrinsic fluorescence and cytotoxicity of purified ricin and abrin in buffers decreased rapidly in a pH- and temperature-dependent manner when treated with sodium hypochlorite but more slowly when treated with peracetic acid. Cytotoxicity assays showed rapid and complete inactivation of ricin and crude abrin in food slurries and dried food residues treated 0-5 min with sodium hypochlorite. Toxin epitopes recognized by ELISA decayed more gradually under these conditions. Higher concentrations of peracetic acid were required to achieve comparable results. Chlorinated alkaline detergent was the most effective industrial agent tested for inactivating ricin in dried food residues.

Validation of a rapid lateral flow test for the simultaneous determination of β-lactam drugs and flunixin in raw milk

β-Lactam antibiotics are the most commonly used drugs on dairy farms. β-Lactam residues in milk are kept out of the human milk supply with good agricultural practices and mandatory truck screening performed by the dairy industry under Appendix N of the Pasteurized Milk Ordinance. Flunixin, a nonsteroidal and anti-inflammatory drug, appears in dairy cattle tissue residues with a frequency similar to the occurrence of penicillin G. This creates concern that flunixin residues could be in milk and would go undetected under current milk screening programs. A single test that combines mandatory β-lactam screening with voluntary flunixin screening is an economical approach for monitoring and controlling for potential flunixin or 5-hydroxyflunixin, the primary flunixin metabolite marker in milk. The objective of this study was to validate a β-lactam and flunixin rapid lateral flow test (LFT) and compare the results obtained with a liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of flunixin and 5-hydroxyflunixin in raw milk with a limit of detection of , 1 ppb, equivalent to 1 ng/ml. Using the LFT, three combined manufactured lots of test strips detected penicillin G at 2.0 ppb, ampicillin at 6.8 ppb, amoxicillin at 5.9 ppb, cephapirin at 13.4 ppb, ceftiofur (total metabolites) at 63 ppb, and 5-hydroxyflunixin at 1.9 ppb at least 90% of the time with 95% confidence. The LFT also detected incurred flunixin milk samples that were analyzed with the LC-MS/MS and diluted to tolerance in raw milk. The detection levels for the LFT are lower than the U.S. safe levels or tolerances and qualify the test to be used in compliance with U.S. milk screening programs.

Effect of high-pressure processing and milk on the anthocyanin composition and antioxidant capacity of strawberry-based beverages

The present study investigated processing strategies and matrix effects on the antioxidant capacity (AC) and polyphenols (PP) content of fruit-based beverages: (1) strawberry powder (Str) + dairy, D-Str; (2) Str + water, ND-Str; (3) dairy + no Str, D-NStr. Beverages were subjected to high-temperature-short-time (HTST) and high-pressure processing (HPP). AC and PP were measured before and after processing and after a 5 week shelf-life study. Unprocessed D-Str had significantly lower AC compared to unprocessed ND-Str. Significant reductions in AC were apparent in HTST- compared to HPP-processed beverages (up to 600 MPa). PP content was significantly reduced in D-Str compared to ND-Str and in response to HPP and HTST in all beverages. After storage (5 weeks), AC and PP were reduced in all beverages compared to unprocessed and week 0 processed beverages. These findings indicate potentially negative effects of milk and processing on AC and PP of fruit-based beverages.

Effect of black currant anthocyanins on the activation of endothelial nitric oxide synthase (eNOS) in vitro in human endothelial cells

Polyphenols are known to induce vasodilatory function via activation of the redox-sensitive phosphatidylinositol-3 (PI3)/protein kinase B (Akt) pathway. Black currant fruits have appreciable amounts of polyphenolic compounds including cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, delphinidin-3-O-glucoside, and delphinidin-3-O-rutinoside. It was hypothesized that black currant fruit extracts would cause activation of endothelial nitric oxide synthase (eNOS) through activation of redox-sensitive PI3 kinase/Akt signaling pathway. To test this hypothesis, human umbilical vein endothelial cells (HUVECs) were treated with different concentrations/times of black currant juice concentrates (Ben Gairn and Ben Hope) and the activation of Akt and eNOS was measured using immunoblotting. Vitamin C is also known to activate Akt and eNOS in in vitro models, and black currants are rich in vitamin C. Therefore, the effect of black currant extracts with and without coexisting vitamin C was investigated, using SPE columns to eliminate vitamin C content. The individual (and combined) effects of the major anthocyanins present in black currant juice samples with and without vitamin C were investigated and compared to the effects of the whole extract. Black currant juice samples (1 μL/mL) significantly increased the phosphorylation of Akt (p-Akt) and eNOS (p-eNOS) (P < 0.05). Activation of Akt and eNOS was abolished by incubation with wortmannin, a PI3K inhibitor, supporting the involvement of PI3K/Akt. Vitamin C alone significantly increased the p-Akt and p-eNOS (P < 0.05); however, removal of vitamin C from black currant did not significantly affect p-Akt and p-eNOS compared to black currant with vitamin C. Assessment of individual anthocyanins also showed significant effects on p-Akt and p-eNOS. In summary, in the present study data suggested that black currant concentrates, Ben Gairn and Ben Hope, activated eNOS via Akt/PI3 kinase pathway in vitro in HUVECs and that the effect was not dependent on vitamin C.