Rapid Surface Plasmon Resonance Immunoassay for the Determination of Deoxynivalenol in Wheat, Wheat Products, and Maize-Based Baby Food

A rapid screening assay (9 min/sample) has been developed and validated for the detection of deoxynivalenol in durum wheat, wheat products, and maize-based baby foods using an SPA biosensor. Through a single laboratory validation, the limits of detection (LOD) for wheat, wheat-based breakfast cereal, and maize-based baby food were 57, 9, and 6 mu g/kg, respectively. Intra-assay and interassay precisions were calculated for each matrix at the maximum and half-maximum European Union regulatory limits and expressed as the coefficient of variation (CV). All CVs fell below 10% with the exception of the between-run CV for breakfast cereal. Recoveries at the concentrations tested ranged from 92 to 115% for all matrices. Action limits of 161, 348, and 1378 mu g/kg were calculated for baby food, wheat-based breakfast cereal, and wheat, respectively, and the linear range of the assay was determined as 250-2000 mu g/kg.

A rapid optical immunoassay for the screening of T-2 and HT-2 toxin in cereals and maize-based baby food

A rapid surface plasmon resonance (SPR) screening assay has been developed for the combined detection of T-2 and HT-2 toxins in naturally contaminated cereals using a sensor chip coated with an HT-2 toxin derivative and a monoclonal antibody. The antibody raised against HT-2 displayed high cross-reactivity with T-2 toxin while there was no cross-reaction observed with other commonly occurring trichothecenes. A simple extraction procedure using 40% methanol was applied to baby food, breakfast cereal, and wheat samples prior to biosensor analysis. Limits of detection (LOD) for each matrix were determined as 25 mu g kg(-1) for baby food and breakfast cereal and 26 mu g kg(-1) for wheat. Intra-assay precision (n = 6) was calculated for each matrix. The results were expressed as the relative standard deviation and determined as 2.8% (100 mu g kg(-1)) and 1.8% (200 mu g kg(-1)) in breakfast cereal, 4.6% (50 mu g kg(-1)) and 3.6% (100 mu g kg(-1)) in wheat and 0.97% (25 mu g kg(-1)) and 6.3% (50 mu g kg(-1)) in baby food. Between run precision (n = 3) performed at the same levels yielded relative standard deviations of 6.7% and 3.9% for breakfast cereals, 3.3% and 1.6% for wheat and 6.8% and 0.08% for baby food, respectively. (C) 2010 Elsevier B.V. All rights reserved.

Production of a monoclonal antibody and its application in an optical biosensor based assay for the quantitative measurement of Pantothenic Acid (Vitamin B5) in foodstuffs

Pantothenicacid (PA), vitamin B5, is an essential B vitamin that may be fortified in food and as such requires robust and accurate methods of detection to meet compliance legislation. This study reports the production and characterisation of the first monoclonalantibody (MAb) specific for PA and the subsequent development of a surface plasmon resonance (SPR) biosensorassay for the quantification of PA. The developed assay was compared with an SPR based commercial kit which utilised a polyclonal antibody (PAb). Foodstuffs, including cereals (n = 43), infant formulas and baby food (n = 10) and fruit juices (n = 48) were analysed by both the MAb and PAb biosensorassays and comparison plots showed good correlation (R2 0.77–0.99). The results indicate that the MAb basedbiosensorassay is suitable for the measurement of PA in foodstuffs and has the added advantage of facilitating a constant, long term supply of identical antibody. Preliminary matrix studies suggest the MAb basedassay is an excellent candidate for further validation studies and routine quality assurance based analysis.

Stability studies of the metabolites of nitrofuran antibiotics during storage and cooking

Nitrofuran antibiotics cannot be used in food production within the European Union because of their potential health risks to consumers. The recent discovery of their widespread use in global food industries and the finding of semicarbazide in baby food as a result of packaging contamination have focused attention on the toxicity and stability of these drugs and their metabolites. The stability of the nitrofuran marker residues 3-amino-2-oxazolidinone (AOZ), 3-amino-5-morpholinomethyl-2-oxazolidone (AMOZ), 1-aminohydantoin (AHD) and semicarbazide (SEM) were tested. Muscle and liver of nitrofuran treated pigs were cooked by frying, grilling, roasting and microwaving. Between 67 and 100% of the residues remained after cooking, demonstrating that these metabolites are largely resistant to conventional cooking techniques and will continue to pose a health risk. The concentration of metabolites in pig muscle and liver did not drop significantly during 8 months of storage at -20 degrees C. Metabolite stock and working standard solutions in methanol were also stable for 10 months at 4 degrees C. Only a 10 ng ml(-1) solution of SEM showed a small drop in concentration over this extended storage period.

Arsenic Contents in Spanish Infant Rice, Pureed Infant Foods, and Rice

It seems there is a positive correlation between rice content and arsenic level in foods. This is of extraordinary importance for infants below 1 y of age because their diet is very limited and in some cases is highly dependent on rice-based products; this is particularly true for infants with the celiac disease because they have no other option than consume gluten-free products, such as rice or corn. Arsenic contents were significantly higher (P <0.001) in gluten-free infant rice (0.057 mg kg-1) than in products with gluten, based on a mixture of cereals (0.024 mg kg-1). Besides, especial precaution must be taken when preparing rice-based products at home, because arsenic content in Spanish rice was high, with levels being above 0.3 mg kg-1 in some cases.

Inorganic arsenic levels in baby rice are of concern

Inorganic arsenic is a chronic exposure carcinogen. Analysis of UK baby rice revealed a median inorganic arsenic content (n = 17) of 0.11 mg/kg. By plotting inorganic arsenic against total arsenic, it was found that inorganic concentrations increased linearly up to 0.25 mg/kg total arsenic, then plateaued at 0.16 mg/kg at higher total arsenic concentrations. Inorganic arsenic intake by babies (4-12 months) was considered with respect to current dietary ingestion regulations. It was found that 35% of the baby rice samples analysed would be illegal for sale in China which has regulatory limit of 0.15 mg/kg inorganic arsenic. EU and US food regulations on arsenic are non-existent. When baby inorganic arsenic intake from rice was considered, median consumption (expressed as mu g/kg/d) was higher than drinking water maximum exposures predicted for adults in these regions when water intake was expressed on a bodyweight basis. (c) 2008 Elsevier Ltd. All rights reserved.

An operant determination of the behavioural mechanism of benzodiazepine enhancement of food intake

Rationale A recent review paper by Cooper (Appetite 44:133–150, 2005) has pointed out that a role for benzodiazepines as appetite stimulants has been largely overlooked. Cooper’s review cited several studies that suggested the putative mechanism of enhancement of food intake after benzodiazepine administration might involve increasing the perceived pleasantness of food (palatability). Objectives The present study examined the behavioral mechanism of increased food intake after benzodiazepine administration. Materials and methods The cyclic-ratio operant schedule has been proposed as a useful behavioral assay for differentiating palatability from regulatory effects on food intake (Ettinger and Staddon, Physiol Behav 29:455–458, 1982 and Behav Neurosci 97:639–653, 1983). The current study employed the cyclic-ratio schedule to determine whether the effects on food intake of chlordiazepoxide (CDP) (5.0 mg/kg), sodium pentobarbital (5.0 mg/kg), and picrotoxin (1.0 mg/kg) were mediated through palatability or regulatory processes. Results The results of this study show that both the benzodiazepine CDP and the barbiturate sodium pentobarbital increased food intake in a manner similar to increasing the palatability of the ingestant, and picrotoxin decreased food intake in a manner similar to decreasing the palatability of the ingestant. Conclusions These results suggest that the food intake enhancement properties of benzodiazepines are mediated through a mechanism affecting perceived palatability.

Application of guar gum as a flocculant aid in food processing and potable water treatment

The paper deals with use of a food grade coagulant (guar gum) as a replacement for synthetic coagulants for potable water treatment.