Glucosinolates as undesirable substances in animal feed - Scientific Opinion of the Panel on Contaminants in the Food Chain

Turning weeds into feed: Ensiling Calotropis gigantea (Giant milkweed) reduces its toxicity and enhances its palatability for dairy cows

Calotropis gigantea (Giant milkweed, GM) has the potential to be utilized as a new feed additive for ruminants, however, the presence of unpalatable or toxic compounds decreases animal feed intake. This study aimed to valorize GM as a potential new feed resource through the chemical and microbial biotransformation of toxic compounds that will henceforth, make the plant palatable for cows. After GM's ensiling using fermentative bacteria, the plant was sampled for UHPLC-MS/MS to analyse the metabolomic changes. Illumina Miseq of the 16 S rRNA fragment genes and ITS1 were used to describe the microbial composition and structure colonizing GM silage and contributing to the biodegradation of toxic compounds. Microbial functions were predicted from metataxonomic data and KEGG pathways analysis. Eight Holstein dairy cows assigned in a cross-over design were supplemented with GM and GM silage to evaluate palatability and effects on milk yield and milk protein. Cows were fed their typical diet prior to the experiment (positive control). After ensiling, 23 flavonoids, 47 amino acids and derivatives increased, while the other 14 flavonoids, 9 amino acids and derivatives decreased, indicating active metabolism during the GM ensiling process. Lactobacillus buchneri, Bacteroides ovatus, and Megasphaera elsdenii were specific to ensiled GM and correlated to functional plant metabolites, while Sphingomonas paucimobilis and Staphylococcus saprophyticus were specific to non-ensiled GM and correlated to the toxic metabolite 5-hydroxymethylfurfural."Xenobiotics biodegradation and metabolism", "cancer overview" and "neurodegenerative disease" were the highly expressed microbial KEGG pathways in non-ensiled GM. Non-ensiled GM is unpalatable for cows and drastically reduces the animal's feed intake, whereas ensiled GM does not reduce feed intake, milk yield and milk protein. This study provides essential information for sustainable animal production by valorizing GM as a new feed additive.

Turning Food Protein Waste into Sustainable Technologies

For each kilogram of food protein wasted, between 15 and 750 kg of CO2 end up in the atmosphere. With this alarming carbon footprint, food protein waste not only contributes to climate change but also significantly impacts other environmental boundaries, such as nitrogen and phosphorus cycles, global freshwater use, change in land composition, chemical pollution, and biodiversity loss. This contrasts sharply with both the high nutritional value of proteins, as well as their unique chemical and physical versatility, which enable their use in new materials and innovative technologies. In this review, we discuss how food protein waste can be efficiently valorized not only by reintroduction into the food chain supply but also as a template for the development of sustainable technologies by allowing it to exit the food-value chain, thus alleviating some of the most urgent global challenges. We showcase three technologies of immediate significance and environmental impact: biodegradable plastics, water purification, and renewable energy. We discuss, by carefully reviewing the current state of the art, how proteins extracted from food waste can be valorized into key players to facilitate these technologies. We furthermore support analysis of the extant literature by original life cycle assessment (LCA) examples run ad hoc on both plant and animal waste proteins in the context of the technologies considered, and against realistic benchmarks, to quantitatively demonstrate their efficacy and potential. We finally conclude the review with an outlook on how such a comprehensive management of food protein waste is anticipated to transform its carbon footprint from positive to negative and, more generally, have a favorable impact on several other important planetary boundaries.

Mineral concentrations in milk from cows fed seaweed (Saccharina latissima) under different basal protein supplementation

Sixteen multiparous Holstein cows in four blocks of 4 × 4 Latin square over 4-week experimental periods were used to study the effects of seaweed (Saccharina latissima) supplement (with/without) and protein source (rapeseed meal (RSM)/wheat distiller's grain (WDG)) on milk mineral concentrations. Dietary treatments did not affect milk production and basic composition. Feeding seaweed slightly decreased milk Ca and Cu concentrations; whilst increased (by 3.3-fold) milk iodine (I) concentration, due to a higher dietary I supply. Substitution of WDG with RSM increased feed-to-milk transfer of Ca, Na, and Se and decreased that of Mg, P, Fe, and Mn; but only reduced milk Mn and I concentrations (the latter by 27 % as a potential result of increased glucosinolate intake). Seaweed supplement can improve milk I content when cows' I supply/availability is limited, but care should be taken to avoid excess milk I contents that may pose nutritional risks for young children.

Effect of the dietary inclusion of Camelina sativa cake into quail diet on live performance, carcass traits and meat quality

The present research studied the effect of the dietary inclusion of 3 different camelina (Camelina sativa (L.) Crantz) cakes on the live performance, slaughter traits, and breast meat quality of broiler quails (Coturnix japonica). With this purpose, a total of 480 fifteen-day-old broiler quails of both sexes were allocated to 48 cages (12 replicates/treatment, 10 quails/replicate) and received 4 dietary treatments: a control diet (Control), and 3 diets containing 15% of 1 commercial cultivar (Calena), and 2 improved lines (Pearl: low linoleic acid; Alan: low glucosinolates). During the experiment, individual live weight (LW) and cage feed intake were recorded to calculate body weight gain (BWG) and feed conversion ratio (FCR). At 35 d of age, quails were slaughtered, and carcasses were weighed and dissected to compute yields. On breast (pectoralis major muscle) the measurements and analyses considered ultimate pH, L*a*b* color values, proximate composition, oxidative status, cooking loss and WBSF toughness. Broiler quails receiving diets with camelina cakes exhibited mortality and health status similar to the control. However, growth performance was impaired in camelina-fed groups, especially for Calena (P < 0.05). Overall LW and BWG were slightly lower, whereas feed intake was slightly higher in camelina-fed groups compared to Control (P > 0.05). Therefore, higher FCR was recorded for camelina-fed groups compared to Control (P = 0.0004). Moreover, breast meat from Calena treatment displayed higher water (P = 0.0170), and lower lipid (P = 0.0051) contents compared to those of the Control group, while protein and ash content remained unaffected. Heme-iron content and oxidative status of breast meat were not influenced by the dietary incorporation of camelina (P > 0.05). The research outcomes indicated that camelina cakes can be used as an alternative feed ingredient for broiler quails' diets, without compromising carcass yields and meat quality. However, as 15% dietary incorporation worsened live performance, the ideal camelina cake inclusion level should be thoroughly investigated as well as a parallel research effort into further reducing glucosinolates content of camelina.

Ablation of glucosinolate accumulation in the oil crop Camelina sativa by targeted mutagenesis of genes encoding the transporters GTR1 and GTR2 and regulators of biosynthesis MYB28 and MYB29

Camelina sativa is an oil crop with low input costs and resistance to abiotic and biotic stresses. The presence of glucosinolates, plant metabolites with adverse health effects, restricts the use of camelina for human and animal nutrition. Cas9 endonuclease-based targeted mutagenesis of the three homeologs of each of the glucosinolate transporters CsGTR1 and CsGTR2 caused a strong decrease in glucosinolate amounts, highlighting the power of this approach for inactivating multiple genes in a hexaploid crop. Mutagenesis of the three homeologs of each of the transcription factors CsMYB28 and CsMYB29 resulted in the complete loss of glucosinolates, representing the first glucosinolate-free Brassicaceae crop. The oil and protein contents and the fatty acid composition of the csgtr1csgtr2 and csmyb28csmyb29 mutant seeds were not affected. The decrease and elimination of glucosinolates improves the quality of the oil and press cake of camelina, which thus complies with international standards regulating glucosinolate levels for human consumption and animal feeding.

Eco-Efficient Quantification of Glucosinolates in Camelina Seed, Oil, and Defatted Meal: Optimization, Development, and Validation of a UPLC-DAD Method

Camelina sativa (camelina) seed, oil, and defatted meal are widely used for food, animal feed, and other purposes. The accurate quantification of camelina glucosinolates is critical as their functionalities are highly dose-dependent. The classic quantification of glucosinolates in camelina products involves tedious desulfation steps, toxic reagents, and a lengthy instrument time because glucosinolates are easy to degrade and subject to interference in the liquid chromatography. Thus, we developed and validated an eco-efficient UPLC-DAD method for determining glucoarabin (GS9), glucocamelinin (GS10), and homoglucocamelinin (GS11) in camelina seed, oil, and defatted meal. Glucosinolates were extracted using 80% cold methanol to denature myrosinase, and were separated by an HSS T3 column without desulfation. Glucotropaeolin was used as an internal standard to track analyte degradation and loss during sample preparation. The method has shown high precision (relative standard deviations ranging from 4.12% to 6.54%) and accuracy (>94.4% spike recovery) for GS9-11, and all validation parameters passed the industry-consensus AOAC Appendix F criteria. To our best knowledge, this is the first eco-efficient and low-cost analytical method that is validated against strict AOAC criteria for the quantification of intact camelina glucosinolates. The method is suitable to be adopted as a new industrial testing standard to assist in the quality control of camelina products.

Influence of rapeseed, canola meal and glucosinolate metabolite (AITC) as potential antimicrobials: effects on growth performance, and gut health in Salmonella Typhimurium challenged broiler chickens

Poultry is the major sources of foodborne salmonellosis. Antibiotic resistance and a surge in zoonotic diseases warrant the use of natural alternatives. Glucosinolates (GLs) are naturally occurring antimicrobial compounds in rapeseed and canola. This study investigated the effect of feeding rapeseed, canola meal, and allyl isothiocyanate (AITC; Brassica secondary metabolites) on growth performance (GP), gut health, and the potential antimicrobial activity against nalidixic acid-resistant Salmonella Typhimurium (STNR) in chickens. A total of 640 one-day-old male Cobb 500 broilers were randomly allocated to 8 treatments with 8 replicated cages and 10 birds per cage. Dietary treatments were nonchallenge control (NC, corn-SBM based), challenge (Salmonella) control (CC), 10% rapeseed (10RS), 30% rapeseed (30RS), 20% canola meal (20CLM), 40% canola meal (40CLM), 500 ppm AITC (500AITC), and 1,500 ppm AITC (1500AITC). On d 1, all the birds except NC were orally challenged with STNR (7 log CFU/bird). The chickens were reared for 21 d, and their FI and BW were recorded weekly. Salmonella cecal colonization and fecal shedding were quantified, whereas organ translocation (OT) of STNR to the spleen, liver, and kidney was tested on 0, 3, 6, 13, and 20-d postchallenge (dpc). Data were subjected to one-way ANOVA, and the means were separated by Duncan's test, except mortality and OT data analyzed after transformation by square root of (n +1) (P < 0.05). Overall, feeding 30RS resulted in reduced BW (P = 0.003), BWG (P = 0.003), and FI (P = 0.001) compared to CC, 500AITC, and 1500AITC. Similarly, feeding 20CLM resulted in lower BW and BWG compared to CC (P < 0.05) and increased FCR compared to 1500AITC (P = 0.03). Feeding CC resulted in higher mortality compared to NC and 30RS (P = 0.03). Cecal colonization of STNR was reduced (P < 0.0001) for 30RS on 6 dpc and 500AITC on 6 and 13 dpc (P < 0.0001). Although no difference in gut permeability was observed 6 dpc (P > 0.05), OT of STNR population was the highest for CC in the spleen (P = 0.05). In the liver, 10RS showed reduced OT compared to 20CLM on 13 dpc (P = 0.03), whereas 30RS showed the lowest OT on 6 dpc in the kidney. Fecal shedding was lowest for 30RS on 6 dpc (P = 0.004). Histomorphology showed 30RS had the highest duodenum (P = 0.01) and jejunum (P = 0.02) villus height (VH) and VH to crypt depth (CD) ratio compared to the other treatments, whereas 1500AITC showed similar results to 30RS. Both 30RS and 1500AITC contained comparatively higher functional GL metabolites and were able to maintain gut health. Including higher levels of rapeseed or AITC in poultry feed can reduce Salmonella colonization in the feces and their translocation to other organs.

Role of Glucosinolates in the Nutraceutical Potential of Selected Cultivars of Brassica rapa

Brassica rapa L. subsp. rapa (turnip greens), a traditionally consumed vegetable, is well-known due to its high content of glucosinolates, which are secondary metabolites with a positive biological activity for human health. Our hypothesis has been based on the relation between B. rapa glucosinolate content and its healthy properties, and our aim is to establish guidelines for safe B. rapa vegetable consumption. Three B. rapa cultivars (143N5, 143N7 and 163N7) have been characterized by HPLC analysis of purified extracts from leaf samples in order to determine their glucosinolate content and to relate this content to beneficial effects on DNA protection, lifespan extension and chemoprevention. In order to ascertain the heath properties in vitro and in vivo, toxicity activities were assayed in the Drosophila melanogaster and leukaemia cell models; genomic safety was also assessed in both models using genotoxicity, fragmentation and comet assay. The Drosophila model has also been used to study the antioxidative activity and the longevity induction. Our results showed a relationship between B. rapa glucosinolate content and its safety and benefices in its consumption. Gluconapin, the main B. rapa glucosinolate, was directly related with these wholesome effects. The relevant conclusion in the present research is focused on B. rapa cultivar 163N7 due to its high gluconapin content and low progoitrin content, which exert anti-cancer and DNA protection properties and could be recommended as being safe and healthy for human consumption.

Milk Production Responses and Digestibility of Dairy Buffaloes (Bubalus bubalis) Partially Supplemented with Forage Rape (Brassica napus) Silage Replacing Corn Silage

Simple Summary

To develop alternative silage resources, we employed buffaloes as an animal model to evaluate the possibility and effects of forage rape silage in the dairy buffalo diet. We comprehensively assessed the nutrition value of forage rape silage by the apparent total-tract digestibility, rumen fermentation characteristics, blood metabolism and milk composition of lactating buffaloes. Our current results showed that the inclusion of forage rape silage in diets improved the milk quality, such as milk protein, milk fat, and total solid percentage. Furthermore, partial supplementation of forage rape silage also promotes buffaloes’ dry matter intake. These may be related to the favorable physiological and metabolic changes induced by the forage rape silage. Thus, our current data show the applicability of forage rape silage as a good feed resource for ruminants.

Abstract

Worldwide, silage is considered the main component in dairy animal diets; however, this portion is mainly dominated by corn silage, which raises availability challenges in some agricultural production systems. The present study evaluated a partial replacement of corn silage with forage rape silage (FRS) and its effect on feed intake, nutrient digestibility, rumen fermentation, milk production, and blood metabolites in buffalo. Thirty-six lactating buffaloes were randomly assigned to four different groups, according to supplementation of FRS (only corn silage, FRS₀) or with 15% (FRS₁₅), 25% (FRS₂₅), and 35% (FRS₃₅) of forage rape silage instead of corn silage. The results showed that, compared to corn silage, forage rape silage has a lower carbohydrate but a higher protein concentration. The buffalo intake of dry matter and organic matter were improved linearly with the FRS increasing in the diet. The apparent total-tract digestibility (ATTD) of dry matter, organic matter, nitrogen, neutral detergent fiber, and acid detergent fiber also increased by the FRS supplementation compared with FRS₀. Conversely, FRS supplementation decreased the propionic, butyric, and valeric acid contents and increased the acetic:propionic ratio and microbial protein content. Furthermore, FRS inclusion led to a significantly higher milk urea and non-fat milk solid content, higher blood glucose, total globulins, blood urea nitrogen, and lower blood high-density lipoprotein. These results suggested that FRS has high a nutritional value and digestibility, is a good feed resource, and showed favorable effects when supplemented with dairy buffalo ration.

Safety of rapeseed powder from Brassica rapa L. and Brassica napus L. as a Novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of rapeseed powder from Brassica rapa L. and Brassica napus L. as a novel food (NF) pursuant to Regulation (EU) 2015/2283. Rapeseed powder will be produced from the seeds of non-genetically modified double low (00) cultivars that are varieties with a low content of erucic acid and reduced content of glucosinolates compared to older varieties. The applicant developed a production process designed to further reduce the content of glucosinolates and other undesirable compounds such as phytates. The NF will be used as a food ingredient added to a number of food products. The target population is the general population from 1 year of age. The maximum estimated intake of the NF is 18-21 g/day in adolescents, adults and elderly (corresponding to 0.35, 0.23 and 0.25 g/kg body weight (bw) per day, respectively). The levels of undesirable compounds in this NF, such as erucic acid, glucosinolates and phytates, are below levels which would raise concerns. The EFSA NDA Panel has previously assessed the safety of similar products for human consumption and there is extensive experience on the use of rapeseed in animal feed. The applicant provided a human study on the safety and tolerability of the NF and no safety concerns were identified. The Panel considers that the NF, i.e. rapeseed powder from Brassica rapa L. and Brassica napus L., is safe at the proposed conditions of use.

Evaluation of Brassica carinata meal as a protein supplement for growing beef heifers1,2

Brassica carinata is a new oilseed crop in Florida with the potential of producing high-quality jet biofuel. A high-protein meal (~40% crude protein; CP) is obtained as a byproduct of oil extraction; however, limited research is available on the utilization of this meal as a protein supplement for beef cattle. A generalized randomized block design was used to evaluate the effects of supplementation with B. carinata meal pellets on performance and attainment of puberty in growing beef heifers consuming bermudagrass hay (Cynodon dactylon) ad libitum. Sixty-four Angus crossbred heifers (240 ± 39 kg initial body weight; BW) were stratified and blocked (2 blocks: light and heavy) by initial BW and randomly allocated into 18 pens over 2 consecutive years (10 in year 1 and 8 in year 2). Within block, pens were randomly assigned to 1 of 2 treatments: 0 (CTL) or 0.3% of BW/d (as fed) of B. carinata meal pellets (BCM). Blood samples and BW were collected weekly for 70 d, before daily supplementation. Data were analyzed using PROC MIXED of SAS with repeated measures. Model included the fixed effects of treatment, day, treatment × day interactions, block, and block × treatment interactions, with the random effect of year. Plasma was analyzed for concentrations of progesterone, triiodothyronine (T3), thyroxine (T4), ceruloplasmin (Cp), and haptoglobin (Hp). An effect of treatment was observed (P ˂ 0.01) for ADG between CTL (0.14 kg) and BCM (0.42 kg). There was no treatment or block (P > 0.05) effect for concentrations of T3, T4, or Hp; however, there was an effect of day (P < 0.01) for T3, T4, and Cp. An effect of treatment (P ˂ 0.01) was observed for Cp, with CTL having greater concentrations compared with BCM. Time to attainment of puberty did not differ (P = 0.93) between treatments. Feeding B. carinata meal as a protein supplement at 0.3% of BW/d is a viable option for increasing ADG of growing beef heifers, without affecting attainment of puberty, thyroid hormone status, or eliciting an acute phase response.

Effects of long-term feeding of rapeseed meal on skeletal muscle transcriptome, production efficiency and meat quality traits in Norwegian Landrace growing-finishing pigs

This study was performed to investigate the effects of dietary inclusion of 20% rapeseed meal (RSM) as an alternative to soybean meal (SBM) in a three-month feeding experiment with growing finishing pigs. Dietary alteration affected growth performance, several carcass traits and transcriptional responses in the skeletal muscle, but did not affect measured meat quality traits. In general, pigs fed the RSM test diet exhibited reduced growth performance compared to pigs on SBM control diet. Significant transcriptional changes in the skeletal muscle of growing pigs fed RSM diet were likely the consequence of an increased amount of fiber and higher polyunsaturated fatty acids, and presence of bioactive phytochemicals, such as glucosinolates. RNAseq pipeline using Tophat2-Cuffdiff identified 57 upregulated and 63 downregulated genes in RSM compared to SBM pigs. Significantly enriched among downregulated pathways was p53-mediated signalling involved in cellular proliferation, while activation of negative growth regulators (IER5, KLF10, BTG2, KLF11, RETREG1, PRUNE2) in RSM fed pigs provided further evidence for reduced proliferation and increased cellular death, in accordance with the observed reduction in performance traits. Upregulation of well-known metabolic controllers (PDK4, UCP3, ESRRG and ESRRB), involved in energy homeostasis (glucose and lipid metabolism, and mitochondrial function), suggested less available energy and nutrients in RSM pigs. Furthermore, several genes supported more pronounced proteolysis (ABTB1, OTUD1, PADI2, SPP1) and reduced protein synthesis (THBS1, HSF4, AP1S2) in RSM muscle tissue. In parallel, higher levels of NR4A3, PDK4 and FGF21, and a drop in adropin, ELOVL6 and CIDEC/FSP27 indicated increased lipolysis and fatty acid oxidation, reflective of lower dressing percentage. Finally, pigs exposed to RSM showed greater expression level of genes responsive to oxidative stress, indicated by upregulation of GPX1, GPX2, and TXNIP.

Evaluation of Brassica carinata meal on ruminant metabolism and apparent total tract digestibility of nutrients in beef steers1,2

Brassica carinata is a new oilseed crop with the potential of producing high-quality jet biofuel. A high-protein meal (~40% crude protein) is obtained as a byproduct of hexane-solvent oil extraction; however, limited research is available on the use of this meal as a protein supplement for beef cattle. A duplicated 4 × 4 Latin square design was used to determine the effects of supplementation with B. carinata meal on ruminal fermentation, digestibility, and blood metabolites in beef cattle consuming bahiagrass hay (Paspalum notatum Flüggé), compared with frequently used protein supplements. Eight Angus crossbred steers (473 ± 119 kg initial BW) were randomly allocated to 8 pens, over 4 periods of 28-d each. Within period, steers were assigned to 1 of 4 treatments: 1) 1.62 kg/d cottonseed meal (CSM); 2) 2.15 kg/d dry distillers grains plus solubles (DDGS); 3) 1.39 kg/d B. carinata meal pellets (BCM); or 4) 1.17 kg/d soybean meal (SBM), supplemented daily, on an isonitrogenous basis. Steers had ad libitum access to bahiagrass hay and water. Intake was measured using the GrowSafe system. Following a 14-d adaptation, feed and fecal samples were collected to determine apparent total tract nutrient digestibility using indigestible NDF as an internal marker. Blood and ruminal fluid samples were collected before providing the protein supplements and then every 3 h, during a 24-h period, to analyze urea nitrogen (PUN) and glucose in plasma, as well as ruminal pH, ammonia nitrogen (NH3-N), and VFA concentrations. Data were analyzed using PROC MIXED of SAS with repeated measures. Model included the fixed effects of treatment, time, treatment × time, square, and period, and the random effects of steer(square) and steer(treatment). No effect of treatment (P > 0.05) was observed for pH, NH3-N, or glucose concentration. An effect of treatment (P < 0.01) was observed for PUN, with steers receiving SBM having greater concentrations. A treatment × time interaction was observed (P < 0.05) for total VFA concentration, acetate to propionate ratio, and molar proportions of acetate, propionate, butyrate, and valerate. Steers consuming SBM had greater molar proportions of branched-chain VFA (P < 0.01) compared with CSM and DDGS. There was no effect of treatment (P > 0.05) on intake or apparent total tract digestibility of nutrients. Brassica carinata performed similarly to commonly used protein supplements indicating its viability as a protein supplement for beef cattle.

Phytochemical Benefits of Agroresidues as Alternative Nutritive Dietary Resource for Pig and Poultry Farming

The growing world population is challenging the animal products supply system, particularly in developing countries, where demand for meat and milk in 2050 is estimated to increase to 109% and 116%, respectively, amidst deteriorating livestock feed sources. Globally, adequate production and availability of animal feed products to subsistence farmers has been declining due to factors such as global warming, growth in population, and low economic growth. This paper seeks to examine the existing scientific literature on the utilization of some unconventional feed resources, to abate the challenge of feed deficit and thus improve animal nutrition. The use of fruit waste and agricultural farm residues affords alternative, nutritive livestock dietary supplements; it has been proven they contain a spectrum of vital bioactive phytochemicals essential for sustainable growth and development of animals. The biochemical composition of the plant wastes and residues include carbohydrates, proteins, nucleic acids, and fatty acids, while the common bioactive phytochemicals are polyphenols, alkaloids, carotenoids, and flavonoids, along with tannins, terpenes, and saponins, which play vital roles in reducing disease-causing agents, such as bacteria, viruses, and free radical-associated diseases. The phytochemicals exhibit antioxidant, antimicrobial, antifungal, and anti-inflammatory, as well as anti-parasitic and antiprotozoal properties. However, it is important to guard against antinutritive and toxicity levels in animal feed products. The paper concludes that agroresidues’/wastes’ nutritive and therapeutic potential could serve as alternative livestock feed resource, while also acting as additional job and income generator for communities.

Endocrine Disrupters and the Safety of Food Chains

Endocrine disrupters (ED) are a heterogeneous group of chemicals including persistent contaminants, pesticides, as well as compounds present in consumer products and natural substances. For most ED, the food chain is a current major exposure route for the general population. ED can enter the food chain through the living environment (e.g., feeds, fertilizers) of food-producing organisms, be directly employed in food production (e.g., pesticides) or be released from food contact materials (such as bisphenol A or phthalates); in addition, the endocrine disruption potential of some natural compounds in edible plants, including the so-called phytoestrogens, should not be overlooked. An exposure assessment has to consider the specific liability of food commodities to contamination with specific ED (e.g., polychlorinated and polybrominated chemicals in lipid-rich foods). The paper discusses the main toxicological research issues in order to support the risk assessment of ED in food chains, including: the potential for additive, 'cocktail' effects (as from multiple pesticide residues); the long-term effects on target body systems (e.g., reproductive, nervous) elicited by exposure during prenatal as well as postnatal life stage windows, and toxicant/nutrient interactions (e.g., thyroid-targeting ED and iodine status). Food safety systems should exploit the available knowledge to improve prevention of long-term risks along the whole food chain.

Iodine in dairy milk: Sources, concentrations and importance to human health

Milk and dairy products are major iodine sources in industrialized countries. However, consumption of milk and dairy, as well as their iodine concentrations, vary widely, making them an unpredictable iodine source. Milk iodine concentrations in industrialized countries range from 33 to 534 μg/L and are influenced by the iodine intake of dairy cows, goitrogen intake, milk yield, season, teat dipping with iodine-containing disinfectants, type of farming and processing. We estimate milk and dairy contribute ≈13-64% of the recommended daily iodine intake based on country-specific food intake data. To ensure adequate iodine levels but avoid the risk of iodine excess through milk and dairy, it is crucial to reduce the wide variations in milk iodine. If iodine intakes from iodized salt fall because of public health efforts to reduce salt intake, milk and dairy products may become increasingly important sources of dietary iodine in the future.