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Modelling the effect of UV light at different wavelengths and treatment combinations on the inactivation of Campylobacter jejuni
Get PDFpeer-reviewedApplication of novel decontamination strategies such as Ultraviolet (UV) irradiation are required to mitigate the risks associated with Campylobacter jejuni in food. This study evaluated the use of a light-emitting diode (LED) based technology to inactivate C. jejuni NCTC 11168 in Maximum Recovery Diluent (MRD) at wavelengths of 280, 300 and 365 nm and combinations. To assess the survival curves, two linear (Log linear (LL) and Linear and Shoulder) and two non-linear models (Weibull and Double Weibull) were fitted. UV exposures showed different antimicrobial effects where a combination of 280/300 nm was the most effective treatment with a 4Dt value of 5 s observed in a bacterial suspension of 5 log CFU/mL. Moreover, the LL model was the most robust model to describe the inactivation kinetics of Campylobacter when exposed to UV and therefore, modelling tools could be applied to predict the efficiency of UV light in a model solution.Industrial relevance: Light-based technologies like UV light are identified in the literature as potential alternatives to assure the decontamination of surfaces, liquids and solid food. However, some of these techniques require further investigation. The present study evaluated the use of a LED system and effect of combined wavelengths in the inactivation of Campylobacter through predictive modelling. This technique was observed to predict and explain kinetics of inactivation of Campylobacter and could be key in the scaling-up process of UV light at industrial level
More than two decades of Agri-Environment schemes: Has the profile of participating farms changed?
Get PDFpeer-reviewedThe agri-food sector is under increased pressure from consumers to improve on the sustainability of production processes. Policies that incentivise farmers to improve environmental performance, such as agri-environment schemes (AES), are increasingly important. Understanding the choice to participate in these programmes aids policymakers in designing schemes that meet participation and environmental goals. While a number of studies have investigated the decision using cross-sectional data on one or multiple locations, very few have used longitudinal data to investigate the impact of institutional changes over time. Using Ireland as a case study, this paper uses a nationally representative panel of data spanning 23 years to model the impact of scheme and policy changes on the type of farms participating in AES. This paper argues that environmental issues surrounding intensive farms (such as the loss of nutrients and sediment to water and greenhouse gas emissions) are not being optimally addressed in scheme design and further development of such programmes is needed to reduce negative environmental impacts
Basic principles in starch multi-scale structuration to mitigate digestibility: A review
Get PDFpeer-reviewedBackgroundIn the human diet, starch makes a significant contribution to the maintenance of human nutrition and health due to its controlled digestibility. Starch digestion is controlled by its microstructure. Increasing developments in the modification of starch multi-scale structures that modulate digestibility have taken place due to increasing attention to health-promoting starchy foods. The process of starch structuration is a challenging concern in food science since the basic principles for designing starch structures with a specific digestibility are unknown. Scope and approachStarch multi-scale structures significantly affect digestibility. However, starch digestibility cannot be precisely modulated without a solid theory of starch structuration to inform the tailoring of the digestibility of starchy foods. In this review, the effects of starch multi-scale structures (fine structures of amylose and amylopectin; short-range ordered structures; helical, crystalline, lamellar, aggregate structures; and structures formed after food processing) on the digestibility and the molecular mechanisms of the regulation of starch digestion are comprehensively discussed. The key structures that can be manipulated for target-modulation of starch digestibility are summarized. Key findings and conclusionsBasic principles for mitigating starch digestibility, such as increasing the thickness of semi-crystalline lamellae and crystalline lamellae, nanoscale aggregates, V-, A-, or B-type crystals, double helices, long amylopectin helices, short-range ordered structures, the content of amylose fractions and high-branched amylopectin are established. Ordered starch structures, including short-range and long-range ordered structures, play critical roles in mitigating starch digestibility while faulty- and perfectly arranged helical, crystalline, lamellar structures, and nano aggregates are proposed to be slowly digestible and resistant starches, respectively
Evaluation of the fertiliser replacement value of phosphorus-saturated filter media
Get PDFpeer-reviewedThe use of filter media to adsorb phosphorus (P) from nutrient-rich waters is an effective, simple and low-cost method to recover and reuse P as an inorganic fertiliser replacement. Although it is assumed that the saturated filter media can be applied to cropland as a safe fertiliser replacement, there is presently a lack of information on the fertiliser replacement value (FRV) of such products and their negative effects on plants and soil. Therefore, the aims of this paper were to evaluate the (1) P removal capacity and plant response to soil application of waste media from three sectors (industry, agriculture, and construction and demolition), and natural and synthetic materials (2) potentially confounding risks arising from the reuse of media as a fertiliser replacement, and (3) factors affecting their fertilising efficiency once applied to soil. The predominant factors affecting the FRV of P-saturated media were their adsorption capacity and chemical composition, soil pH, and composition of water used for saturation. Some measures to overcome the negative impacts of the land application of P-saturated media include selecting the most appropriate soil-filter material combinations, the use of P solubilising microorganisms, and mixing with manure before land application. Despite confounding factors and a lack of information on the performance of some media under comparable study conditions, this study found that there is a significant potential for P-saturated filter media to partially replace the use of P mineral fertilisers and aid in the attainment of a “circular economy” in agriculture
Assessing the ability of nisin A and derivatives thereof to inhibit gram-negative bacteria from the genus Thermus
Get PDFpeer-reviewedNisin is a bacteriocin that is globally employed as a biopreservative in food systems to control gram-positive, and some gram-negative, bacteria. Here we tested the bioactivity of nisin A-producing Lactococcus lactis NZ9700 and producers of bioengineered variants thereof against representatives of the gram-negative genus Thermus, which has been associated with the pink discoloration defect in cheese. Starting with a total of 73 nisin variant-producing Lactococcus lactis, bioactivity against Thermus was assessed via agar diffusion assays, and 22 variants were found to have bioactivity greater than or equal to that of the nisin A-producing control. To determine to what extent this enhanced bioactivity was attributable to an increase in specific activity, minimum inhibitory concentrations were determined using the corresponding purified form of these 22 nisin A derivatives. From these experiments, nisin M17Q and M21F were identified as peptides with enhanced antimicrobial activity against the majority of Thermus target strains tested. In addition, several other peptide variants were found to exhibit enhanced specific activity against a subset of strains
Objective carcass measurement technologies: Latest developments and future trends
Get PDFpeer-reviewedBackgroundCarcass evaluation is a key process to ascertain the value and the quality characteristics of the animal at slaughter. In addition to being the base for monetary transactions between livestock producers and meat processors, in some countries, this evaluation also helps to determine the market allocation of cuts. Recent advances in non-invasive techniques are being tested for their potential to improve classification and grading systems in the meat industry. Scope and approachIn this review, global grading and classification practices for pig, sheep and beef carcasses are discussed along with the latest technological developments in objective carcass measurement. We discuss a number of studies predicting marketable attributes such as yield (lean and saleable meat yield), eating quality attributes (inter- and intra-muscular fat, meat and fat colour) and carcass dimensions (skeletal structure, ribeye area). Technologies based on x-ray, nuclear magnetic resonance, video image analysis, ultrasound, bioelectric impedance and spectroscopy are discussed, along with recent developments and their possible future adoption. Key findings and conclusionsDual-energy x-ray absorptiometry and magnetic induction technologies have been commercialised for the sheep and pig industries, respectively. X-ray technologies and updates in video image analysis could go beyond grading to improve yield and cut dimension predictions. Some technologies could improve process efficiencies through cut sorting and enabling robotic cutting, while also enabling improved value-based payment systems. However, there are challenges associated with their implementation in meat processing plants and further research and development is required in some areas
The effect of machine traffic zones associated with field headlands on soil structure in a survey of 41 tilled fields in a temperate maritime climate
Get PDFpeer-reviewedMachinery traffic imposes a negative effect on soil structure, leading to soil compaction. Studies to date have primarily focused on the influence of applied wheel loads on soil structure. Few studies have assessed the impact of commercial farm operations on soil structure and crop performance, particularly on field headlands in a temperate maritime climate such as Ireland. A survey was conducted on 41 conventionally managed field sites to investigate the effect of field position (field edge, turning, transition and in-field zones) in relation to machinery operations on soil structure. Soil texture classes ranged from sandy loam to clay loam. All sites used plough-based crop establishment. Soil structural condition was assessed visually using the visual evaluation of soil structure method (VESS) for the topsoil (0−250 mm), and Double Spade below plough depth (250−400 mm). Quantitative soil measurements such as shear strength, bulk density and porosity using soil cores post-harvest, and soil cone penetration resistance were taken at two time points in the crop growth cycle. For most measurements of soil structure, the in-field zone of least machinery traffic produced the best scores (Sq 2.81 & DS 2.48), and the turning zone returned the poorest scores in the 0−250 mm soil layer (Sq 3.31 & DS 2.91). The strongest quantitative scores for the in-field and turning zones, respectively, were for trowel penetration resistance in the upper (2.49 & 3.20) and lower (3.41 & 4.05) soil depth layers and for shear vane (38.17 & 53.59 kPa) for the same zones. The visual assessments and some of the quantitative measurements (0−250 mm soil layer) followed the zone order trend of: turning, field edge, transition and in-field, for increasing machinery traffic. The results show that the visual soil indicators used in this study are more sensitive than quantitative soil measurements such as soil bulk density (ρb) or porosity (TP and MP) at detecting soil structural differences between zones, particularly below plough depth (>250 mm soil depth)
Investigation of intra-day variability of gaseous measurements in sheep using portable accumulation chambers
Get PDFpeer-reviewedPortable accumulation chambers (PAC) enable short-term spot measurements of gaseous emissions including methane (CH4), carbon dioxide (CO2), and oxygen (O2) consumption from small ruminants. To date the differences in morning and evening gaseous measurements in the PAC have not been investigated. The objectives of this study were to investigate: 1) the optimal measurement time in the PAC, 2) the appropriate method of accounting for the animal’s size when calculating the animal’s gaseous output, and 3) the intra-day variability of gaseous measurements. A total of 12 ewe lambs (c. 10 to 11 months of age) were randomly selected each day from a cohort of 48 animals over nine consecutive days. Methane emissions from the 12 lambs were measured in 12 PAC during two measurement runs daily, AM (8 to 10 h) and PM (14 to 16 h). Animals were removed from Perennial ryegrass silage for at least 1 h prior to measurements in the PAC and animals were assigned randomly to each of the 12 chambers. Methane (ppm) concentration, O2 and CO2 percentage were measured at 5 time points (T1 = 0.0 min, T2 = 12.5 min, T3 = 25.0 min, T4 = 37.5 min, and T5 = 50.0 min from entry of the first animal into the first chamber) using an Eagle 2 monitor. The correlation between time points T5-T1 (i.e., 50 min minus 0 min after entry of the animal to the chamber) and T4-T1 was 0.95, 0.92, and 0.77 for CH4, O2, and CO2, respectively (P < 0.01). The correlation between CH4 and CO2 output and O2 consumption, calculated with live-weight and with body volume was 0.99 (P < 0.001). The correlation between the PAC measurement recorded on the same animal in the AM and PM measurement runs was 0.73. Factors associated with CH4 production included: day and time of measurement, the live-weight of the animal and the hourly relative humidity. Results from this study suggest that the optimal time for measuring an animal’s gaseous output in the PAC is 50 min, that live-weight should be used in the calculation of gaseous output from an animal and that the measurement of an animal’s gaseous emissions in either the AM or PM does not impact on the ranking of animals when gaseous emissions are measured using the feeding and measurement protocol outlined in the present study.Irish Department of Agricultur
Enhanced pyrazolopyrimidinones cytotoxicity against glioblastoma cells activated by ROS-Generating cold atmospheric plasma
Get PDFpeer-reviewedPyrazolopyrimidinones are fused nitrogen-containing heterocyclic systems, which act as a core scaffold in many pharmaceutically relevant compounds. Pyrazolopyrimidinones have been demonstrated to be efficient in treating several diseases, including cystic fibrosis, obesity, viral infection and cancer. In this study using glioblastoma U-251MG cell line, we tested the cytotoxic effects of 15 pyrazolopyrimidinones, synthesised via a two-step process, in combination with cold atmospheric plasma (CAP). CAP is an adjustable source of reactive oxygen and nitrogen species as well as other unique chemical and physical effects which has been successfully tested as an innovative cancer therapy in clinical trials. Significantly variable cytotoxicity was observed with IC50 values ranging from around 11 μM to negligible toxicity among tested compounds. Interestingly, two pyrazolopyrimidinones were identified that act in a prodrug fashion and display around 5–15 times enhanced reactive-species dependent cytotoxicity when combined with cold atmospheric plasma. Activation was evident for direct CAP treatment on U-251MG cells loaded with the pyrazolopyrimidinone and indirect CAP treatment of the pyrazolopyrimidinone in media before adding to cells. Our results demonstrated the potential of CAP combined with pyrazolopyrimidinones as a programmable cytotoxic therapy and provide screened scaffolds that can be used for further development of pyrazolopyrimidinone prodrug derivatives
Effects of grass and maize silage feed value, offering soybean meal with maize silage, and concentrate feed level in late pregnancy, on ewe and lamb performance
Get PDFpeer-reviewedIn many countries, daily herbage accumulation on pasture declines towards zero during the winter period; thus, many pregnant ewes are housed and offered conserved forages supplemented with concentrate prior to parturition. The effects of forage type and feed value (FV), offering soybean meal with maize silage during mid and late pregnancy, and concentrate feed level in late pregnancy on the performance of ewes and their progeny (to slaughter) were evaluated. Ewes (n = 151) were assigned to one of nine treatments from mid-pregnancy until lambing. Medium FV and high FV grass silages (metabolisable energy concentrations of 10.7 and 12.0 MJ/kg DM) were offered ad libitum supplemented with either 15 or 25 kg concentrate/ewe during late pregnancy. Low and high DM maize silages (starch concentrations of 80 and 315 g/kg DM) were offered ad libitum either alone or with soybean meal (200 g/d) and supplemented with 15 kg concentrate during late pregnancy. A final treatment consisted of high FV grass silage supplemented with 5 kg soybean/ewe over the final 4 weeks of pregnancy. Ewes and lambs were put to pasture in a rotational-grazing system within 3 days of lambing. There were no interactions (P > 0.05) between grass silage FV and concentrate feed level for ewe or lamb traits. Increasing grass silage FV increased food intake (P 0.05) on ewe or lamb performance. Increasing maize DM at harvest and offering soybean meal with maize silage increased food intake (P 0.05) on animal performance. Replacing grass silage with maize silage did not affect (P > 0.05) BW gain of lambs. It is concluded that increasing the FV of the grass silage offered during pregnancy had the greatest positive impact on ewe and lamb performance.Teagasc, Carlow, R93 XE12, Irelan