Salmonella surveillance in raw and cooked meat and meat products in the Republic of Ireland from 2002 to 2004

The food industry, under the regulation of the Department of Agriculture and Food (DAF) in the Republic of Ireland, is required to undertake all microbiological testing in relation to zoonoses control, in laboratories approved by DAF. These laboratories submit a monthly report of all tests undertaken, together with all presumptive Salmonella isolates for confirmation, typing and storage to the Central Veterinary Research Laboratory (CVRL). Details of Salmonella tests on 110,229 raw and 25,189 cooked meat samples from 25 laboratories were recorded over the 3-year period 2002-2004. Salmonella spp. were isolated from 1.0% of the 110,229 raw meat samples and 0.1% of the 25,189 cooked meat samples tested. The percentage of raw meat samples contaminated with Salmonella decreased over the three-year period from 1.2% to 0.9%. There was no seasonal trend in the isolation of Salmonella from any of the meats or meat products. Recoveries of the organism were highest for turkey and chicken meats at 3.1% and 2.8%, respectively, followed by porcine meats at 2.1%. The recoveries were much lower for ovine meats and meat products at 0.2% and bovine meat and meat products at 0.16%.     

Preparation and characterization of sulfonated poly(tetra phenyl ether ketone sulfone)s for proton exchange membrane fuel cell

Sulfonated poly(tetra phenyl ether ketone sulfone)s SPTPEKS were successfully synthesized for proton exchange membrane. Poly(tetra phenyl ether ketone sulfone)s PTPEKS were prepared by the 4,4′-dihydroxydiphenylsulfone with 1,2-bis(4-fluorobenzoyl)-3,4,5,6-tetraphenylbenzene (BFBTPB) and 4,4′-difluorodiphenylsulfone, respectively, at 210 °C using potassium carbonate in sulfolane. PTPEKS were followed by sulfonation using chlorosulfonic acid and concentrated sulfuric acid at two stage reactions. Different contents of sulfonated unit of SPTPEKS (17, 20, 23 mol% of BFBTPB) were studied by FT-IR, ¹H NMR spectroscopy, and thermo gravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water. The ion exchange capacity (IEC) and proton conductivity of SPTPEKS were evaluated with increase of degree of sulfonation. The water uptake of synthesized SPTPEKS membranes exhibit 25–61% compared with 28% of Nafion 211^®. The SPTPEKS membranes exhibit proton conductivities (25 °C) of 11.7–25.3 × 10⁻³ S/cm compared with 33.7 × 10⁻³ S/cm of Nafion 211^®.     

Whey protein isolate polydispersity affects enzymatic hydrolysis outcomes

The effects of heat-induced denaturation of whey protein isolate (WPI) on the enzymatic breakdown of α-La, caseinomacropeptide (CMP), β-Lg A and β-Lg B were observed as hydrolysis proceeded to a 5% degree of hydrolysis (DH) in both unheated and heat-treated (80 °C, 10 min) WPI dispersions (100 g L⁻¹). Hydrolysis of denatured WPI favoured the generation of higher levels of free essential amino acids; lysine, phenylalanine and arginine compared to the unheated substrate. LC–MS/MS identified 23 distinct peptides which were identified in the denatured WPI hydrolysate – the majority of which were derived from β-Lg. The mapping of the detected regions in α-La, β-Lg, and CMP enabled specific cleavage points to be associated with certain serine endo-protease activities. The outcomes of the study emphasise how a combined approach of substrate heat pre-treatment and enzymology may be used to influence proteolysis with attendant opportunities for targeting unique peptide production and amino acid release.     

Herd manager attitudes and intentions regarding the selection of high-fertility EBV sires in Australia

Reproductive performance in dairy cattle has declined over the last 50 years as an unintended consequence of selection for high milk yield. Since the early 2000s, dairy geneticists have released successive versions of fertility estimated breeding values (EBV) to assist in reversing this trend. At the herd level, fertility EBV can help managers accelerate improvements in reproductive performance by acting as a second selection criteria when used in tandem with a breeding index. However, use of the fertility EBV in sire selection currently varies between herd managers. The aim of this study was to better understand the reasons why herd managers choose or do not choose to select high-fertility EBV sires, using the Theory of Planned Behavior (TPB) as a social research framework. Thirty-five Victorian dairy herd managers were recruited as part of a larger study investigating the daughter fertility Australian Breeding Value and interviewed using a series of questions examining TPB constructs. The interviews were recorded and transcribed using template analysis. A wide range of herd manager types were enrolled into the study, with representation from diverse systems. Out of the 35 herd managers, 27 included fertility in their list of high-priority breeding objectives. A wide variation in results was consistent with previous studies that have demonstrated marked heterogeneity in herd manager attitudes toward bull selection. Herd manager-perceived barriers to selection of sires with high daughter fertility EBV included a lack of high daughter fertility bulls with other desirable traits, a lack of trust in the fertility EBV or in the Australian EBV system, difficulty in interpreting international proofs, information overload, semen prices, low bull reliability, and difficulty in understanding bull catalogs. Not all herd managers found the process problematic, however, particularly if a breeding consultant was employed to select all or most of the sires. Herd manager-perceived barriers for choosing to select daughter fertility as a breeding objective include a lack of awareness of the EBV, a lack of interest in genetics in general, low confidence in the impact of genetic selection for fertility, and a feeling that fertility was not important for their production system. The results of this study suggest that animal geneticists and on-farm service providers need to work together to allow the opportunities arising from appropriate use of fertility EBV to be realized more broadly across the dairy industry.     

Menthol cigarettes and health risks in Lung Health Study data.

Whether menthol cigarettes confer a higher risk of death than plain cigarettes is not known. The Lung Health Study (LHS) enrolled 5,887 adult smokers in a clinical trial of smoking cessation and ipratropium in the prevention of chronic obstructive pulmonary disease. LHS participants have been subjected to surveillance for mortality from all causes for 14 years. We examined these data for differences between self-reported smokers of menthol cigarettes versus plain cigarettes. Using proportional hazards regression methods, we found no differences in hazard ratios for coronary heart disease, cardiovascular disease, lung cancer, or death from any cause. Contrary to expectations about nicotine dependence, we found that users of menthol cigarettes had smoked fewer pack-years at baseline. We found no difference in success at smoking cessation with or without menthol. We conclude that our data contain no evidence that mentholation of cigarettes increases the hazards of smoking.     

Economic and health risk trade-offs of swim closures at a Lake Michigan beach

This paper presents a framework for analyzing the economic, health, and recreation implications of swim closures related to high fecal indicator bacteria (FIB) levels. The framework utilizes benefit transfer policy analysis to provide a practical procedure for estimating the effectiveness of recreational water quality policies. Evaluation criteria include the rates of intended and unintended management outcomes, whether the chosen protocols generate closures with positive net economic benefits to swimmers, and the number of predicted illnesses the policy is able to prevent. We demonstrate the framework through a case study of a Lake Michigan freshwater beach using existing water quality and visitor data from 1998 to 2001. We find that a typical closure causes a net economic loss among would-be swimmers totaling dollars 1274-37,030/day, depending on the value assumptions used. Unnecessary closures, caused by high indicator variability and a 24-h time delay between when samples are taken and the management decision can be made, occurred on 14 (12%) out of 118 monitored summer days. Days with high FIB levels when the swim area is open are also common but do relatively little economic harm in comparison. Also, even if the closure policy could be implemented daily and perfectly without error, only about 42% of predicted illnesses would be avoided. These conclusions were sensitive to the relative values and risk preferences that swimmers have for recreation access and avoiding health effects, suggesting a need for further study of the impacts of recreational water quality policies on individuals.     

A spatial analytic framework for assessing and improving food aid distribution in developing countries

Undernutrition is responsible for nearly half of all deaths of children under five years of age. In the developing world, where many communities rely on subsistence farming, one way of combating undernutrition is through food aid provided by governmental and non-governmental organizations. In this analysis we develop a flexible optimization based approach to support food aid planning capable of incorporating a variety of inputs to capture micro-scale food demand. We apply this optimization model to the specific case of Mali, one of the poorest countries in the world, with large food aid programs. The results are compared to the current distribution of food aid outlets as presented by the World Food Program and suggest that an optimization based framework provides quantitative-based insights of demand and resource allocation useful for planning efforts. In particular, the results indicate that a reallocation of existing food aid outlets towards more dense areas where vegetation is reduced could markedly increase access to outlets by those with food needs. The developed approach has potential to support ongoing efforts to reduce food insecurity and improve the cost-effective targeting of food aid in Mali and elsewhere.     

Development of a simple model device for in vitro gastric digestion investigation

There have been some reports in the literature of model gastric digestion systems to mimic the dynamic physiological processes within the gastrointestinal tract. However, such devices often require the specification of many control parameters making routine digestion tests unfeasible. This paper introduces a simple in vitro digestion device, comprising of a water-jacketed glass vessel into which a spherical Teflon probe of variable diameter can be inserted. The probe is controlled by a texture analyser to simulate the kinetics of a food digestion process. Using this device under well controlled hydrodynamic flow and biochemical conditions key digestion parameters such as pH, food particle size, protein release, lipid release, cloudiness, etc, can be determined. Feasibility tests of the model device have been conducted using roasted and non-roasted peanuts particles. The status of peanut digestion was examined by the changes in particle size distribution and the mean particle size. Significant differences of surface microstructure have also been observed for peanut particles after the digestion. The influence of parameters such as food to gastric juice ratio, the probe speed and pepsin concentration have been examined in this work. Initial results confirm that all these factors influence the kinetic process of gastric digestion considerably and should be well regulated in any in vitro digestion investigations. We propose that the model device has the advantages of easy control and operation and furthermore could be an ideal tool for routine in vitro gastric digestion studies.     

A validated PCR-based method to detect Listeria monocytogenes using raw milk as a food model--towards an international standard

A PCR assay with an internal amplification control was developed for Listeria monocytogenes. The assay has a 99% detection probability of seven cells per reaction. When tested against 38 L. monocytogenes strains and 52 nontarget strains, the PCR assay was 100% inclusive (positive signal from target) and 100% exclusive (no positive signal from nontarget). The assay was then evaluated in a collaborative trial involving 12 European laboratories, where it was tested against an additional 14 target and 14 nontarget strains. In that trial, the inclusivity was 100% and the exclusivity was 99.4%, and both the accordance (repeatability) and the concordance (reproducibility) were 99.4%. The assay was incorporated within a method for the detection of L. monocytogenes in raw milk, which involves 24 h of enrichment in half-Fraser broth followed by 16 h of enrichment in a medium that can be added directly into the PCR. The performance characteristics of the PCR-based method were evaluated in a collaborative trial involving 13 European laboratories. In that trial, a specificity value (percentage of correct identification of blank samples) of 81.8% was obtained; the accordance was 87.9%, and the concordance was 68.1%. The sensitivity (correct identification of milk samples inoculated with 20 to 200 L. monocytogenes cells per 25 ml) was 89.4%, the accordance was 81.2%, and the concordance was 80.7%. This method provides a basis for the application of routine PCR-based analysis to dairy products and other foodstuffs and should be appropriate for international standardization.