Innovations in beef production systems that enhance the nutritional and health value of beef lipids and their relationship with meat quality

Consumers are becoming more aware of the relationships between diet and health and this has increased consumer interest in the nutritional value of foods. This is impacting on the demand for foods which contain functional components that play important roles in health maintenance and disease prevention. For beef, much attention has been given to lipids. This paper reviews strategies for increasing the content of beneficial omega-3 polyunsaturated fatty acids (PUFA) and conjugated linoleic acid (CLA) and reducing saturated fatty acids (SFA) in beef. Particular attention is given to intramuscular fat (IMF) and the relationships between fatty acid composition and key meat quality parameters including colour shelf life and sensory attributes. Despite the high levels of ruminal biohydrogenation of dietary PUFA, nutrition is the major route for increasing the content of beneficial fatty acids in beef. Feeding grass or concentrates containing linseed (rich in α-linolenic acid, 18:3n-3) in the diet increases the content of 18:3n-3 and its longer chain derivative eicosapentaenoic acid (EPA, 20:5n-3) in beef muscle and adipose tissue, resulting in a lower n-6:n-3 ratio. Grass feeding also increases docasahexaenoic acid (DHA, 22:6n-3). Feeding PUFA rich lipids which are protected from ruminal biohydrogenation result in further enhancement of the PUFA in meat with concomitant beneficial improvements in the ratio of polyunsaturated:saturated fatty acids (P:S ratio) and n-6:n-3 ratio. The main CLA isomer in beef is CLA cis-9, trans-11 and it is mainly associated with the triacylglycerol lipid fraction and therefore is positively correlated with level of fatness. The level of CLA cis-9, trans-11 in beef is related to (1) the amount of this isomer produced in the rumen and (2) synthesis in the tissue, by delta-9 desaturase, from ruminally produced trans vaccenic acid (18:1 trans-11; TVA). Feeding PUFA-rich diets increases the content of CLA cis-9, trans-11 in beef. Trans-fatty acids in foods are of rising importance and knowledge of the differential effects of the individual trans isomers is increasing. TVA is the major trans 18:1 isomer in beef and as the precursor for tissue CLA in both animals and man should be considered as a neutral or beneficial trans-isomer. Increasing the content of n-3 PUFA in beef can influence colour shelf life and sensory attributes of the meat. As the content of n-3 PUFA increases then sensory attributes such as "greasy" and "fishy" score higher and colour shelf life may be reduced. Under these situations, high levels of vitamin E are necessary to help stabilise the effects of incorporating high levels of long chain PUFA into meat. However, grass feeding not only increases n-3 PUFA and CLA but, due to its high content of vitamin E, colour shelf life is improved. It is evident that opportunities exist to enhance the content of health promoting fatty acids in beef and beef products offering opportunities to add value and contribute to market differentiation. However, it is imperative that these approaches to deliver "functional" attributes do not compromise on the health value (lipoperoxidation) or the taste of beef products.     

Microcapsule production by an hybrid colloidosome-layer-by-layer technique

Although many different methods for microencapsulation are known only some of them had been applied at industrial scale, due to complexity, lack of mechanical strength of the resulting capsules, and the costs related to their production. One of such methods is the electrostatic layer-by-layer (LbL) adsorption, which produce shells from oppositely charged polymers. The thickness of those shells can be tuned with nanometric precision, but to build enough strength for practical applications requires the adsorption of an impractical number of layers. We present here a method to produce strong microcapsules combining the assembly of a protein/pectin shell via electrostatic LbL adsorption with the adsorption of bigger charged colloidal particles. Those colloidal particles do not need any pretreatment to modify their wettability, as would be the case for a standard colloidosome route. In this way strong encapsulates with porous walls are obtained, which can be used as easy to load scaffolds. The pores in the walls can be closed through subsequent adsorption of more layers of protein and pectin. Since the assembly scheme occurs at pH 3.5 we expect the produced microcapsules to act as an effective delivery system in food products, protecting their contents from the acidity of the stomach and dissolving later at the small intestine. The proteins and pectins used as basic building blocks are food-grade and inexpensive.     

Estimation of Listeria monocytogenes transfer coefficients and efficacy of bacterial removal through cleaning and sanitation

Listeria monocytogenes is readily found in the environment of retail deli establishments and can occasionally contaminate food handled in these establishments. Here we synthesize the available scientific evidence to derive probability distributions and mathematical models of bacterial transfers between environmental surfaces and foods, including those during slicing of food, and of bacterial removal during cleaning and sanitizing (models available at www.foodrisk.org). Transfer coefficients varied considerably by surface type, and after log(10) transformation were best described by normal distributions with means ranging from -0.29 to -4.96 and standard deviations that ranged from 0.07 to 1.39. 'Transfer coefficients' during slicing were best described by a truncated logistic distribution with location 0.07 and scale 0.03. In the absence of protein residues, mean log inactivation indicated a greater than 5 log(10) reduction for sanitization with hypochlorite (mean: 6.5 log(10); 95% confidence interval (CI): 5.0-8.1 log(10)) and quaternary ammonium compounds (mean: 5.5 log(10); 95% CI: 3.6-7.3 log(10)), but in the presence of protein residues efficacy reduced dramatically for hypochlorite (mean: 3.8 log(10); 95% CI: 2.1-5.4 log(10)) as well as quaternary ammonium compounds (mean: 4.4log(10); 95% CI: 2.5-6.4 log(10)). Overall, transfer coefficients are therefore low, even though cross-contamination can be extremely efficient under certain conditions. Dozens of food items may consequently be contaminated from a single contaminated slicer blade, albeit at low concentrations. Correctly performed sanitizing efficiently reduces L. monocytogenes contamination in the environment and therefore limits cross-contamination, even though sanitization is only performed a few times per day. However, under unfavorable conditions reductions in bacterial concentration may be far below 5 log(10). The probability distributions and mathematical models derived here can be used to evaluate L. monocytogenes cross-contamination dynamics in environments where foods are handled, and to assess the potential impact of different intervention strategies.     

High concentrations of essential and toxic elements in infant formula and infant foods – A matter of concern

This study assessed concentrations in and intake of toxic and essential elements from formulas and foods intended for infants during their first 6 months of life. Concentrations of the essential elements Ca, Fe, Zn, Mn and Mo were significantly higher in most formulas than in breast milk. Daily intake of Mn from formula varies from ten up to several hundred times the intake of the breast fed infant, levels that may be associated with adverse health effects. One portion of infant food provided significantly more Fe, Mn, Mo, As, Cd, Pb and U than one feeding of breast milk, but less Ca, Cu and Se. Rice-based products in particular contained elevated As concentrations. Drinking water used to mix powdered formula may add significantly to the concentrations in the ready-made products. Evaluation of potentially adverse effects of the elevated element concentrations in infant formulas and foods are warranted.     

Prevalence, distribution, and diversity of Listeria monocytogenes in retail environments, focusing on small establishments and establishments with a history of failed inspections

Despite growing concerns about cross-contamination of ready-to-eat foods with Listeria monocytogenes, our knowledge about the ecology and transmission of L. monocytogenes in retail establishments has remained limited. We conducted a cross-sectional study to characterize the prevalence, distribution, and subtype diversity of L. monocytogenes in 120 New York State retail deli establishments that were hypothesized to present an increased risk for environmental L. monocytogenes contamination (i.e., small establishments and establishments with a history of failed New York State Agriculture and Markets inspections). Analysis of these data along with previously reported data for 121 predominantly larger retail establishments in New York State identified establishment size, geographic location, and inspection history as significant predictors of L. monocytogenes presence and prevalence. The odds of an establishment being L. monocytogenes positive were approximately twice as high for large establishments, establishments located in New York City, or establishments with poor inspection history (as compared with establishments without these attributes), even though correlation between location and inspection history complicated interpretation of results. Within an establishment, L. monocytogenes was significantly more prevalent on nonfood contact surfaces than on food contact surfaces; prevalence was particularly high for floors and in floor drains, sinks, the dairy case, and milk crates. L. monocytogenes subtype diversity differed between sites, with lineage I isolates significantly associated with nonfood contact surfaces and lineage II isolates significantly associated with food contact surfaces. Isolates belonging to the same ribotype were often found dispersed across multiple sites within an operation.     

Combining Data Longevity with High Storage Capacity—Layer‐by‐Layer DNA Encapsulated in Magnetic Nanoparticles

In this paper the practical density of long‐term DNA storage is increased. Specifically, the DNA weight loading of silica sphere DNA storage is increased to 3.4 wt%, a ten‐fold increase compared to the previous state‐of‐the‐art. By applying a Layer‐by‐Layer (LbL) design with alternating layers of DNA and a polycationic molecule, namely polyethyleneimine (PEI), another dimension to DNA surface binding onto magnetic nanoparticles is added. A protective silica layer is grown on top of the multilayered nanoparticles to shield the DNA from external sources of damage. Accelerated aging experiments of the nanoparticles and the subsequent quantification of DNA stability via qPCR show a significantly lower degradation rate compared to unprotected DNA. The novel material is compared to previous DNA storage technologies, outperforming those in DNA storage density as well as stability. Finally, the storage of an 83 kB digital file in DNA through a successful readout of a 4991 oligonucleotide pool is demonstrated from particle encapsulation, through accelerated aging, to sequencing.     

Marginal Abatement Cost Curves for Water Scarcity Mitigation under Uncertainty

Water Resources Management - As water scarcity and drought become more common, planning to avoid their consequences becomes crucial. Measures to prevent the impact of new climate conditions are...     

Regional Sentiment Bias in Social Media Reporting During Crises

Crisis events such as terrorist attacks are extensively commented upon on social media platforms such as Twitter. For this reason, social media content posted during emergency events is increasingly being used by news media and in social studies to characterize the public’s reaction to those events. This is typically achieved by having journalists select ‘representative’ tweets to show, or a classifier trained on prior human-annotated tweets is used to provide a sentiment/emotion breakdown for the event. However, social media users, journalists and annotators do not exist in isolation, they each have their own context and world view. In this paper, we ask the question, ‘to what extent do local and international biases affect the sentiments expressed on social media and the way that social media content is interpreted by annotators’. In particular, we perform a multi-lingual study spanning two events and three languages. We show that there are marked disparities between the emotions expressed by users in different languages for an event. For instance, during the 2016 Paris attack, there was 16% more negative comments written in the English than written in French, even though the event originated on French soil. Furthermore, we observed that sentiment biases also affect annotators from those regions, which can negatively impact the accuracy of social media labelling efforts. This highlights the need to consider the sentiment biases of users in different countries, both when analysing events through the lens of social media, but also when using social media as a data source, and for training automatic classification models.     

Towards analysing the rationale of information security non-compliance: Devising a Value-Based Compliance analysis method

Employees’ poor compliance with information security policies is a perennial problem. Current information security analysis methods do not allow information security managers to capture the rationalities behind employees’ compliance and non-compliance. To address this shortcoming, this design science research paper suggests: (a) a Value-Based Compliance analysis method and (b) a set of design principles for methods that analyse different rationalities for information security. Our empirical demonstration shows that the method supports a systematic analysis of why employees comply/do not comply with policies. Thus we provide managers with a tool to make them more knowledgeable about employees’ information security behaviours.