In poultry, feed based on maggots, like larvae of black soldier fly (Hermetia illucens) is an attractive option to substitute current ingredients which are expensive and often in direct or indirect competition with human food. Little information is currently available on the utility of these larvae in poultry feed, so goals of this study were to determine whether larvae could be reared on horse manure under traditional farming conditions and to evaluate the growth performances of a local poultry fed these larvae and the fatty acids profiles of their meat. After freezing and thawing, larvae were introduced in the feed of Ardennaise chickens between 30 and 80 days of age. Birds in the control group received a commercial standard feed, while those in the treatment group received the same commercial feed in which 8% was substituted with whole fresh larvae corresponding to 2% on a dry matter basis. Means ± standard errors of larval length and weight were 20.67 ± 2.21 mm and 0.14 ± 0.02 g, respectively. Mean larval percentages of dry matter and of substances extractable in diethyl ether were 24.6% and 23.1%, respectively. Larval fatty acids profiles were predominantly composed of lauric acid (28.1%) and palmitic acid (22.0%). Least squares means of weekly weights of chicken, adjusted for the effects of sex, replication and initial weights, were significantly higher (P < 0.05) by 77.03 ± 53.37 g in larvae-fed than in control chickens. All other measurements were not statistically different between larvae-fed and control chicken, including fatty acid profiles, protein content and ω6/ω3 ratio.

Knowing that polyunsaturated fatty acids can lead to the formation of potentially toxic aldehydes as secondary oxidation products, an analytical method using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) detection was developed to measure the concentration of eight aldehydes in animal feed: malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE), 4-hydroxy-2-hexenal (4-HHE), crotonaldehyde (CRT), benzaldehyde (BNZ), hexanal (HXL), 2,4-nonadienal, and 2,4-decadienal. The developed method was validated according to the criteria and procedure described in international standards. The evaluated parameters were specificity/selectivity, recovery, precision, accuracy, uncertainty, limits of detection and quantification, using the concept of accuracy profiles. These parameters were determined during experiments conducted over three different days with ground Kellogg's® Corn Flakes® cereals as model matrix for animal feed and spiked at different levels of concentration. Malondialdehyde, 4-HHE, 4-HNE, crotonaldehyde, benzaldehyde, and hexanal can be analyzed in the same run in animal feed with a very good accuracy, with recovery rates ranging from 86 to 109% for a working range going from 0.16 to 12.50 mg/kg. The analysis of 2,4-nonadienal and 2,4-decadienal can also be performed but in a limited range of concentration and with a limited degree of accuracy. Their recovery rates ranged between 54 and 114% and coefficient of variation for the intermediate precision between 11 and 25% for these two compounds. Copyright © 2016 John Wiley & Sons, Ltd.

Vietnam is an important producer of aquaculture products, and aquatic products are essential to the Vietnamese diet. However, Vietnam also has very little enforced regulation pertaining to antibiotic usage in domestic aquaculture, which raises concerns for antibiotic resistance in pathogenic bacteria. In this study, analysis was conducted on the presence of antibiotic residues in domestically sold fish and shrimp raised in freshwater farms in Vietnam, and an assessment of farmers’ knowledge of proper antibiotics usage was performed. The results indicated that a quarter of tested aquaculture products were antibiotic screening test positive, and there is a general lack of knowledge about the purpose and proper usage of antibiotics by aquaculture producers. Farmers’ decision-making processes about antimicrobial use are influenced by biased sources of information, such as drug manufacturers and sellers, and by financial incentives.

Secondary oxidation products of fatty acids, mainly aldehydes, are susceptible to cause significant deterioration in chemical, sensory and nutritional food properties, as well as adverse health effects. An analytical method involving separation by liquid chromatography coupled to the detection by tandem mass spectrometry (LC-MS/MS) has been developed to evaluate the concentration of four aldehydes in oil samples: malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE), 4-hydroxy-2-hexenal (4-HHE) and 2,4-decadienal (2,4-DECA). The optimisation of the extraction, derivation, detection and quantification has been finalised for coconut oil, used as a model of vegetable oils. The method has been validated according to the criteria and procedure described in international standards. The evaluated parameters include specificity/selectivity, recovery, precision, accuracy, uncertainty, limits of detection and quantification, using the concept of accuracy profiles. These parameters have been evaluated during experiments planned on different non-consecutive days with coconut oil spiked at different levels of concentration. The validation of the developed analytical method showed that it is possible to analyse MDA, 4-HHE, 4-HNE and 2,4-decadienal in oil samples, in the same run, with a very good accuracy for MDA, and a defined accuracy at specified concentrations for the three other aldehydes. The accuracy profile of MDA showed a recovery rate of 100 % (±1) and a maximum coefficient of variation for the intermediate precision of 14 % at 0.15 mg kg−1. For the three other aldehydes, recovery rates ranged between 79 and 101 % and coefficient of variation for the intermediate precision between 13 and 23 %. In first pressure linseed oil, stored for several days at 60 °C according to the Schaal oven test, it was shown that 4-HHE was the most produced aldehyde, reaching levels of 85 and 382 μmol kg−1 after 12 and 24 days, respectively, versus levels of 18 and 28 μmol MDA kg−1 of oil, respectively, and 17 and 51 μmol 4-HNE kg−1 of oil.

The fatty acids (FA) profile was determined in n-3 enriched (Columbus™) Belgian eggs and pork in order to evaluate to what extent the n-3 fatty acids, which are very sensitive to oxidation, are resistant to storage or cooking. In standard eggs or pork, no change of the fatty acid profile was observed after storage or cooking without culinary fat, as well as in Columbus™ eggs and pork after storage. Some cooking processes (eggs in custard and meat in oven) induced a slight significant loss of n-3 fatty acids in Columbus™ eggs or pork (11.1% in fat from eggs cooked in custard vs. 15.3% in raw Columbus™ eggs and 11.0% in fat from oven cooked meat vs. 11.6% in raw Columbus™ meat). As expected, when Columbus™ pork is cooked with culinary fat, its fatty acid profile is modified according to the nature of the fat used.

The presence of antibacterial in 97 pork and 83 chicken meat samples, rando mly collected fro m 3 different representative provinces (Hanoi, Hai Duong and Thai Binh) of the Red River Delta, was determined by a screening step using in parallel 2 microbiological methods (Premi ® -test and New Two Plate Test). In total, 27% of all samples displayed a positive response in at least one of both tests, from which 11 (13% of chicken samples) are ch icken samples and 38 (39% of pork samples) are pork samples. The 33 samples fro m the Thai Binh which were screened positive were then submitted to post-screening tests specific for tetracyclines and (fluoro) quinolones (Tetrasensor ® dipstick for tetracyclines and an ELISA for quinolones), two groups of antibiotics widely used in animal production in this region, and confirmed by liquid chromatography coupled to mass spectrometry. Tetracyclines and (fluoro)quinolones residues were found, using a post screening test, in 23 and 5 samp les, respectively. Ten (all pork) and 4 samples (1 pork, 3 chicken) were confirmed containing tetracyclines (chlortetracycline, o xytetracycline, tetracycline, do xycycline) and (fluoro) quinolones (nalidixic acid, enroflo xacin and ciproflo xacin) respectively, fro m which 1 and 3 pork samples were found to contain enrofloxacin and tetracycline residues , respectively, with a concentration higher than their respective MRLs. This study shows the good performance of the proposed strategy to identify non-co mpliant meat samples (microbiological screening, tetracyclines and quinolones targeted post-screening and confirmation), which allows to obtain conclusive results in 82% of the cases.

Summary A two‐plate microbiological method to screen residues of the most commonly used antibiotics in animal production, named new two‐plate test (NTPT), has been optimised and validated, according to criteria derived from the European Commission Decision 2002/657/CE. This screening method used two media at different pH seeded with a single bacteria strain ( Bacillus subtilis) . The method consists of a simple extraction, followed by the application of the extract on Petri plates. The method detected, in pork and chicken muscles, most of the antibiotics from six groups (tetracyclines, (fluoro)quinolones, penicillins, macrolides, aminoglycosides and sulfonamides) and florfenicol at concentration very close to maximum residue limits used in the EU. The screening capacity of the NTPT was compared with another screening technique, the Premi‐Test ® , by analysing spiked samples as well as real samples of meat from pork and chicken sold for local consumption, in the Red River Delta region (Vietnam). The NTPT described here appeared to detect more samples than the Premi‐Test ® , showing its interest for Vietnamese control laboratories, as a screening method to monitor antibiotic residues in chicken and pork meat, before sending the suspected samples to the confirmatory step.

Microbiological inhibition screening tests could play an important role to detect residues of antibiotics in the different animal food products, but very few are available for the aquaculture products in general, and for shrimps in particular. A two-plate microbiological method to screen shrimp for residues of the most commonly used antibiotics has been developed and validated according to criteria derived from the European Commission Decision 2002/657/CE. Bacillus subtilis was used as a sensitive strain to target antibiotics. Culture conditions on Petri plates (pH of medium) were selected to enhance the capacity of antibiotic detection. Antibiotic residues were extracted from shrimps using acetonitrile/acetone (70/30, v/v) before application on Petri plates seeded with B. subtilis. The method was validated using spiked blank tissues as well as antibiotic treated shrimps with enrofloxacin and tetracycline, two antibiotics often found to be used in shrimp production. For tetracyclines and (fluoro)quinolones, the detection capability was below the maximum residue limit (MRL), while it was around the MRL for sulfonamides. The specificity of the microbiological screening was 100% in all cases while the sensitivity and accuracy was 100% in almost all cases. The capacity of the method to detect contaminated samples was confirmed on antibiotic treated shrimps, analyzed in parallel with a confirmatory method (Liquid Chromatography coupled to mass spectrometry (LC–MS)).

The number of substances with beta-agonistic activity, illegally introduced in meat production or in sports doping as anabolic or beta-blocking agents is increasing. Analytical methods suited for their multianalyte detection are thus necessary. In this perspective, receptor assays were developed. The research activities undertaken in this study describe the solubilisation of a recombinant human beta(2)-adrenergic receptor produced in the inner membrane of genetically modified Escherichia coli, using the detergent n-dodecyl-beta-d-maltoside. Its potential to detect the presence of beta-agonists or beta-blockers in biological samples was evaluated. The solubilised beta(2)-adrenergic receptor retained its binding affinity in a radio-receptor assay based on the competition for the binding to receptors between a ligand (beta-agonist or antagonist) and the radioligand [(125)I]iodocyanopindolol. The IC(50) values ranged from 5+/-1 x 10(-8) M (clenbuterol) to 8+/-2 x 10(-6) M (isoxsuprine) for the beta-agonists tested and from 1.5+/-0.2 x 10(-10) M (carazolol) to 1.2+/-0.2 x 10(-5) M (metoprolol) for the beta-blockers tested. It was shown to have a lower limit of detection than a radio-receptor assay using the solubilised beta(2)-adrenoceptor expressed in a mammalian cell line. The solubilised recombinant human beta(2)-adrenoreceptor expressed in E. coli would be a useful tool to develop non radioactive multianalyte screening methods.