Optimization of Antibacterial, Physical and Mechanical Properties of Novel Chitosan/Olibanum Gum Film for Food Packaging Application

Chitosan-based films are promising active biodegradable materials with the ability to be enhanced by different materials, including gums. This study aims to optimize the physical (transmittance, water vapor permeability and water solubility), mechanical (tensile strength and elongation at break) and antibacterial (against Staphylococcus aureus and Salmonella Typhimurium) properties of newly fabricated chitosan/olibanum gum (CH/OG) films as a function of different levels of CH (0.5, 0.75, 1, 1.25 and 1.5% w/v) and OG (0.125, 0.25, 0.375, 0.5 and 0.625% w/v), using response surface methodology (RSM). Moreover, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and differential scanning calorimetry (DSC) were used to better characterize the fabricated films. RSM analysis results showed the significant fitting of all dependent variable responses to the quadratic polynomial model. To attain the desirable physical, mechanical and antibacterial responses, the optimal concentrations were 1.31% (w/v) CH and 0.3% (w/v) OG. The encouraging antibacterial, physical and mechanical properties of the developed composites support the application of chitosan/gum blends in active food packaging, particularly for perishable foodstuffs, such as meat and horticultural products.

Heavy metal wombats? Metal exposure pathways to bare-nosed wombats (Vombatus ursinus) living on remediated tin mine tailings

Rehabilitation of disused mine sites through stabilisation and botanical restoration is ecologically important, but metal transfer pathways to colonising wildlife are often less understood and have never been studied in marsupials. The rehabilitated Royal George tin mine tailings (Tasmania, Australia) and colonisation by bare-nosed wombats (Vombatus ursinus) represented an opportunity to examine potential metal transfer from mine tailings to an herbivorous marsupial. The aim of this study was to examine metal transfer pathways from the mine tailings to wombats, and to determine if wombats are at risk from metal exposure. Concentrations of metals were measured in the tailings substrate, surface water and vegetation, as well as fur samples from a resident wombat, and non-resident (control) wombats. The mineralogy of the tailings is dominated by quartz, muscovite, feldspars, topaz, kaolinite and calcite. Concentrations of several metals were high (exceeding varying health standards) in the tailings (As, Cu, Hg, Pb, Ni, Zn), water (As, Cd, Cu, Zn) and vegetation (As, Cd, Cu, Pb, Mn, Zn). Relative to non-resident wombats, elevated levels of As, Cd, Cu, Pb and Sn were measured in the fur of a resident wombat. Based on modelling of the exposure pathways, consumption of plant material is the most likely metal transfer pathway for As, Cu and Pb, although the risks from ingestion of tailings to this fossorial marsupial should not be discounted. This study is the first to investigate metal exposure pathways to marsupials using rehabilitated mine tailings. Further research is needed to accurately quantify ecological risks and toxicity for wombats and other marsupials native to mining landscapes.

Assessment of human exposure to environmental sources of lead arising from the lead battery manufacturing and recycling sector in Europe: demonstration of a tiered approach in a case study

BACKGROUND

Standard approaches for the assessment of Man via the Environment exposure are designed to be conservative. However, propagating these exposures into health impact assessment might lead to questionable socio-economic costs.

OBJECTIVE

The objective of this study was to develop a novel tiered modelling approach to assess human exposure to lead (Pb) via the environment.

METHOD

The approach starts in Tier 1 from EUSES modelling approach, modified with metal specific transfer factors. The generic Tier 2 approach uses the higher tier model GPM for air quality, and dietary exposure modelling based on EFSA's Comprehensive Food Database, in combination with crop specific transfer factors. Tier 3 considers additional site-specific information such as proximity of inhabitants and agricultural activities in relation to industrial sites.

RESULTS

This tiered modelling approach was applied to a case study of 50 lead battery manufacturing and recycling sites across Europe. Data sets from general population human biomonitoring studies were used to compare the predicted additional bioburden of Pb resulting from lead battery manufacturing and recycling. The higher tier assessments were able to demonstrate a >20-fold reduction in modelled Pb exposure compared to default assumptions made in Tier 1.

SIGNIFICANCE

Leading to better estimates for socio-economic costs in health impact assessment.

Factors during Production of Cereal-Derived Feed That Influence Mycotoxin Contents

Mycotoxins are naturally present in cereal-based feed materials; however, due to adverse effects on animal health, their presence in derived animal feed should be minimized. A systematic literature search was conducted to obtain an overview of all factors from harvest onwards influencing the presence and concentration of mycotoxins in cereal-based feeds. The feed production processes covered included the harvest time, post-harvest practices (drying, cleaning, storage), and processing (milling, mixing with mycotoxin binders, extrusion cooking, ensiling). Delayed harvest supports the production of multiple mycotoxins. The way feed materials are dried after harvest influences the concentration of mycotoxins therein. Applying fungicides on the feed materials after harvest as well as cleaning and sorting can lower the concentration of mycotoxins. During milling, mycotoxins might be redistributed in cereal feed materials and fractions thereof. It is important to know which parts of the cereals are used for feed production and whether or not mycotoxins predominantly accumulate in these fractions. For feed production, mostly the milling fractions with outer parts of cereals, such as bran and shorts, are used, in which mycotoxins concentrate during processing. Wet-milling of grains can lower the mycotoxin content in these parts of the grain. However, this is typically accompanied by translocation of mycotoxins to the liquid fractions, which might be added to by-products used as feed. Mycotoxin binders can be added during mixing of feed materials. Although binders do not remove mycotoxins from the feed, the mycotoxins become less bioavailable to the animal and, in the case of food-producing animals, to the consumer, lowering the adverse effects of mycotoxins. The effect of extruding cereal feed materials is dependent on several factors, but in principle, mycotoxin contents are decreased after extrusion cooking. The results on ensiling are not uniform; however, most of the data show that mycotoxin production is supported during ensiling when oxygen can enter this process. Overall, the results of the literature review suggest that factors preventing mycotoxin production have greater impact than factors lowering the mycotoxin contents already present in feed materials.

Current knowledge on urease and nitrification inhibitors technology and their safety

OBJECTIVE

Urea is one of the most widely used commercial fertilisers worldwide due to its high N density and cost effectiveness. However, it can be lost in the form of gaseous ammonia and other greenhouse gas (GHG) emissions which can potentially lead to environmental pollution. Farmers are compelled to apply more urea to account for those losses, thereby increasing their expenditure on fertilization. The objective of this paper is to present a literature review on current knowledge regarding inhibitor technologies such as urease inhibitor; n-(N-butyl) thiophosphoric triamide (NBPT), and nitrification inhibitor; dicyandiamide (DCD).

METHODS

A thorough review of all the scientific literature was carried out and a proposed risk assessment framework developed.

RESULTS

The study showed that the urease inhibitor NBPT significantly reduced NH3 loss from urea. However, concerns about NBPT safety to human health had been raised when the nitrification inhibitor DCD appeared as a residue in milk. This article presents a risk assessment framework for evaluating human exposure to chemicals like NBPT or DCD, following the consumption of foods of animal origin (e.g. milk) from cows grazing on inhibitor-treated pasture.

CONCLUSION

The EU's target of a 40% reduction of greenhouse gas emissions by 2030 can be aided by using NBPT as part of an overall suite of solutions. A comprehensive risk assessment is advised for effective evaluation of potential risks from exposure to these inhibitors.

Application of adsorption process for effective removal of emerging contaminants from water and wastewater

Emerging pollutants in the marine ecosystem, as well as their possible impact on live species, have become a rising cause of worry. A traditional wastewater treatment plants alone are not successful in eliminating such massive contaminant groups and therefore additional water treatment is required which is to be cost effective. Since standard primary and secondary treatment plants are unsuccessful at eliminating or degrading these harmful chemicals, a cost-effective tertiary treatment approach is proposed. Adsorption is a successful approach for Contaminants removal globally, because it is low installation expense, high performance and has easy operational design. Emerging pollutants have been removed from wastewaters using various adsorbents like activated carbons, improved bio chars, Nano adsorbents, hybrid adsorbents, and others. The purpose of this paper is to review the source of contaminants and the concept of adsorption when separating emerging contaminants. The present study aims to examine the adsorption mechanism as an effective approach for treating emerging contaminants. Then, the analysis of natural and man-made adsorbents for the separation of contaminants is examined along with its comparison. Also, future view on emerging contaminants and adsorbents in modern generation has been discussed.

A review of microbes and chemical contaminants in dairy products in sub-Saharan Africa

Animal milk types in sub-Saharan Africa (SSA) are processed into varieties of products using different traditional methods and are widely consumed by households to support nutritional intake and diet. Dairy products contain several microorganisms, their metabolites, and other chemical compounds, some with health benefits and many others considered as potential health hazards. Consumption of contaminated milk products could have serious health implications for consumers. To access the safety of milk products across SSA, studies in the region investigating the occurrences of pathogens as well as chemical compounds such as heat stable toxins and veterinary drug residues in animal milk and its products were reviewed. This is done with a holistic view in light of the emerging exposome paradigm for improving food safety and consumer health in the region. Herein, we showed that several published studies in SSA applied conventional and/or less sensitive methods in detecting microbial species and chemical contaminants. This has serious implications in food safety because the correct identity of a microbial species and accurate screening for chemical contaminants is crucial for predicting the potential human health effects that undermine the benefits from consumption of these foods. Furthermore, we highlighted gaps in determining the extent of viral and parasitic contamination of milk products across SSA as well as investigating multiple classes of chemical contaminants. Consequently, robust studies should be conducted in this regard. Also, efforts such as development cooperation projects should be initiated by all stakeholders including scientists, regulatory agencies, and policy makers to improve the dairy product chain in SSA in view of safeguarding consumer health.

Potential contaminants and hazards in alternative chicken bedding materials and proposed guidance levels: a review

Bedding material or litter is an important requirement of meat chicken production which can influence bird welfare, health, and food safety. A substantial increase in demand and cost of chicken bedding has stimulated interest in alternative bedding sources worldwide. However, risks arising from the use of alternative bedding materials for raising meat chickens are currently unknown. Organic chemicals, elemental, and biological contaminants, as well as physical and management hazards need to be managed in litter to protect the health of chickens and consequently that of human consumers. This requires access to information on the transfer of contaminants from litter to food to inform risk profiles and assessments to guide litter risk management. In this review, contaminants and hazards of known and potential concern in alternative bedding are described and compared with existing standards for feed. The contaminants considered in this review include organic chemical contaminants (e.g., pesticides), elemental contaminants (e.g., arsenic, cadmium, and lead), biological contaminants (phytotoxins, mycotoxins, and microorganisms), physical hazards, and management hazards. Reference is made to scientific literature for acceptable levels of the above contaminants in chicken feed that can be used for guidance by those involved in selecting and using bedding materials.

Adverse Effects, Transformation and Channeling of Aflatoxins Into Food Raw Materials in Livestock

Aflatoxins are wide-spread harmful carcinogenic secondary metabolites produced by Aspergillus species, which cause serious feed and food contaminations and affect farm animals deleteriously with acute or chronic manifestations of mycotoxicoses. On farm, both pre-harvest and post-harvest strategies are applied to minimize the risk of aflatoxin contaminations in feeds. The great economic losses attributable to mycotoxin contaminations have initiated a plethora of research projects to develop new, effective technologies to prevent the highly toxic effects of these secondary metabolites on domestic animals and also to block the carry-over of these mycotoxins to humans through the food chain. Among other areas, this review summarizes the latest findings on the effects of silage production technologies and silage microbiota on aflatoxins, and it also discusses the current applications of probiotic organisms and microbial products in feeding technologies. After ingesting contaminated foodstuffs, aflatoxins are metabolized and biotransformed differently in various animals depending on their inherent and acquired physiological properties. These mycotoxins may cause primary aflatoxicoses with versatile, species-specific adverse effects, which are also dependent on the susceptibility of individual animals within a species, and will be a function of the dose and duration of aflatoxin exposures. The transfer of these undesired compounds from contaminated feed into food of animal origin and the aflatoxin residues present in foods become an additional risk to human health, leading to secondary aflatoxicoses. Considering the biological transformation of aflatoxins in livestock, this review summarizes (i) the metabolism of aflatoxins in different animal species, (ii) the deleterious effects of the mycotoxins and their derivatives on the animals, and (iii) the major risks to animal health in terms of the symptoms and consequences of acute or chronic aflatoxicoses, animal welfare and productivity. Furthermore, we traced the transformation and channeling of Aspergillus-derived mycotoxins into food raw materials, particularly in the case of aflatoxin contaminated milk, which represents the major route of human exposure among animal-derived foods. The early and reliable detection of aflatoxins in feed, forage and primary commodities is an increasingly important issue and, therefore, the newly developed, easy-to-use qualitative and quantitative aflatoxin analytical methods are also summarized in the review.

Metal (Pb, Cu, Cd, and Zn) Transfer along Food Chain and Health Risk Assessment through Raw Milk Consumption from Free-Range Cows

Background: Metal transfer along the food chain has raised concerns about impacts on human health due to dietary exposure to low but chronic concentrations. Soil–forage–milk–consumer is a short food chain through which metals are able to reach an organism. Methods: Pb, Cu, Cd, and Zn were determined in water, soil, forage, and milk samples collected from free-range cattle farms situated near Baia Mare, Romania. The soil-to-forage (TF_sf) and forage-to-milk (TF_fm) transfer factors for metals and the health risk for three population groups (females, males, and children) through the consumption of milk containing low levels of metals were assessed. Results: TF_sf indicated that the uptake capabilities of the metals from soil to forage were in the following order: Zn > Cd > Cu > Pb. TF_fm indicated a lack of metal accumulation through forage ingestion. Estimated daily (EDI) and provisional tolerable weekly (PTWI) intake values revealed a minimal exposure of the population to those metals through milk consumption. A noncarcinogenic hazard index indicated that milk consumption from local markets does not pose any risk for human health; however, the average cancer risk showed a high potential carcinogenic risk. Conclusions: The consumption of milk produced by small local farmers does not pose noncarcinogenic risks. More extended studies should be carried out in order to identify the potential carcinogenic risk caused by the low levels of metals in the milk consumed.

Simultaneous Determination of Eight Monoalkyl Phthalate Esters in Porcine Tissue by Solid-Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry

An improved method for solid-phase extraction (SPE)-liquid chromatography-tandem mass spectrometry was developed to analyze eight monoalkyl phthalate esters (MPEs) in eight different kinds of porcine tissues. The tissue samples were processed using enzymatic deconjugation with β-glucuronidase, followed by SPE with Oasis MAX cartridges. A pentafluorophenyl column was first used to solve the coeluting issues of MPE isomers. The limits of detection and recoveries were 0.01-0.6 ng/g and 62.5-123.7%, respectively. The intra- and interday precisions were less than 7.1 and 9.4%, respectively. The robust method was successfully applied for the investigation of MPEs in various porcine tissue samples collected from markets in Beijing, China. The occurrence of MPEs with total concentrations of 48.0-108 ng/g was detected, and monoethylhexyl phthalate was the predominant MPE (accounting for 30-57%) in all of the porcine tissue samples. The results will be helpful in assessing the potential risks of diets that include pork.

Recent trends in common chemical feed and food contaminants in Israel

In February 2014 a new law was approved by the Israeli parliament, namely the Control of Animal Feed Law. The law intends to regulate the production and marketing of animal feed. In preparation for the law's implementation in 2017, we have assessed the current feed and food safety challenges in Israel in recent years in association with the presence of common undesirable contaminants in various common feed and food commodities. Tight collaboration between regulatory authorities and feed/food industry, enhanced feed and food quality monitoring, transparency of survey results and readily accessible and reliable information for the public about health hazards of chemical contaminants, will guarantee the safety and quality of food and feed.

Mycotoxin contamination of foods in Southern Africa: A 10-year review (2007-2016)

Major staple foods in Southern Africa are prone to mycotoxin contamination, posing health risks to consumers and consequent economic losses. Regional climatic zones favor the growth of one or more main mycotoxin producing fungi, Aspergillus, Fusarium and Penicillium. Aflatoxin contamination is mainly reported in maize, peanuts and their products, fumonisin contamination in maize and maize products and patulin in apple juice. Lack of awareness of occurrence and risks of mycotoxins, poor agricultural practices and undiversified diets predispose populations to dietary mycotoxin exposure. Due to a scarcity of reports in Southern Africa, reviews on mycotoxin contamination of foods in Africa have mainly focused on Central, Eastern and Western Africa. However, over the last decade, a substantial number of reports of dietary mycotoxins in South Africa have been documented, with fewer reports documented in Botswana, Lesotho, Malawi, Mozambique, Zambia and Zimbabwe. Despite the reported high dietary levels of mycotoxins, legislation for their control is absent in most countries in the region. This review presents an up-to-date documentation of the epidemiology of mycotoxins in agricultural food commodities and discusses the implications on public health, current and recommended mitigation strategies, legislation, and challenges of mycotoxin research in Southern Africa.

Purified deoxynivalenol or feed restriction reduces mortality in rainbow trout, Oncorhynchus mykiss (Walbaum), with experimental bacterial coldwater disease but biologically relevant concentrations of deoxynivalenol do not impair the growth of Flavobacterium psychrophilum

Diets containing deoxynivalenol (DON) were fed to rainbow trout Oncorhynchus mykiss (Walbaum) for 4 weeks followed by experimental infection (intraperitoneal) with Flavobacterium psychrophilum (4.1 × 10(6) colony-forming units [CFU] mL(-1) ). Mortality of rainbow trout fed either 6.4 mg kg(-1) DON or trout pair-fed the control diet was significantly reduced (P < 0.05) in comparison with trout fed the control diet to apparent satiation (<0.1 mg kg(-1) DON). In a second experiment, trout were fed one of three experimental diets; a control diet, a diet produced with corn naturally contaminated with DON (3.3 mg kg(-1) DON) or a diet containing purified DON (3.8 mg kg(-1) ); however, these fish were not experimentally infected. The presence of DON resulted in significant reduction (P < 0.0001) in feed intake as well as weight gain after 4 weeks. Respiratory burst of head-kidney leucocytes isolated from rainbow trout fed diets containing purified DON (3.8 mg kg(-1) ) was significantly higher (P < 0.05) at 35 day post-exposure compared with controls. The antimicrobial activity of DON was examined by subjecting F. psychrophilum in vitro to serial dilutions of the chemical. Complete inhibition occurred at a concentration of 75 mg L(-1) DON, but no effect was observed below this concentration (0-30 mg L(-1) ).

Carryover of maduramicin from feed containing cross-contamination levels into eggs of laying hens

Maduramicin is a coccidiostat authorized as feed additive in the European Union for chickens and turkeys for fattening but not for laying hens, considering the risk of residues in eggs. The unavoidable cross-contamination of non-target feed with coccidiostats is regulated by Commission Directive 2009/8/EC and resulting carry-over in food by Commission Regulation (EC) No. 124/2009. To verify the compliance of the maximum levels for maduramicin in feed (50 μg/kg) and eggs (2 μg/kg), the carry-over from feed into eggs was investigated. Diets containing 10, 30, and 50 μg of maduramicin/kg of feed were fed to laying hens. Feed, egg white, and yolk were analyzed by LC-MS/MS. Maduramicin residues were only detected in in egg yolk. Feeding the 10 μg/kg maduramicin diet resulted in maduramicin concentrations up to 2.5 μg/kg in whole eggs, already exceeding the maximum level. A carry-over rate of 8% maduramicin from feed into eggs was calculated.