Exposure assessment of cattle via roughages to plants producing compounds of concern.

Food producing animals are exposed to biologically active plant compounds through feed and roughages, presenting a potential risk to the animal but also consumers of food of animal origin. To evaluate to which plant compounds of concern dairy cows in the Netherlands are exposed, a ranking filter model was developed, combining information on abundance of plant species in vegetation plots in the Netherlands (183,905 plots of three different vegetation types) with plant-compound combinations (700), and with consumption data of fresh grass, grass silage and corn silage by cattle. The most abundant plant genera are those producing cyanogenic glycosides, coumarins and benzofuranocoumarins, being predominantly fodder plants (alfalfa, clover and some grasses) considered to be safe. Highest exposures were estimated for plant genera producing piperidine alkaloids (horsetail), furanocoumarins (parsley and relatives), pyrrolizidine alkaloids (Symphytum, Senecio, Leucanthemum, Eupatorium) and essential oils. The current results allow to prioritise future scientific research on these compounds.

The occurrence of fumonisin B1 in maize-containing foods in The Netherlands.

Seventy-eight maize-containing foods obtained from retail stores in The Netherlands were analysed for fumonisin B1 contamination. Thirty-six per cent of the samples were contaminated with fumonisin B1 in the range of 8 micrograms kg-1 (limit of detection) to 1430 micrograms/kg-1. Forty-six per cent of the minimally treated maize samples (n = 39; maize for bread production, maize for popcorn, maize flour and polenta) were contaminated with fumonisin B1 in the range of 8-380 micrograms kg-1. Twenty-six per cent of the maize-containing processed foods (n = 39; tostada, canned maize, maize starch, maize bread, popped maize, flour mixes, maize chips and cornflakes) were contaminated with fumonisin B1 in the range of 8-1430 micrograms/kg-1. This survey shows that maize-containing foods in The Netherlands frequently can be contaminated with fumonisin B1.

Fumonisin B1 in maize for food production imported in The Netherlands.

Sixty-two samples of maize imported in The Netherlands and intended for human consumption were screened for the presence and concentration of fumonisin B1. Sixty-one of those samples contained fumonisin B1 with concentrations ranging from 30 to 3350 micrograms kg-1, 11 maize samples contained > 1000 micrograms kg-1. The average fumonisin B1 concentration was 640 micrograms kg-1 for the positive samples and 620 micrograms kg-1 for all samples. Medians were 600 micrograms kg-1 and 550 micrograms kg-1 for positive and all samples, respectively. The results obtained were comparable to results from other studies in maize from various countries.

Assessment of human exposure to fumonisin B1.

Fumonisin B1 is currently regarded as the most significant mycotoxin produced by Fusarium spp. It has carcinogenic properties and may play a role in the etiology of human esophageal cancer. The human population is exposed to fumonisin B1 primarily by intake of fumonisin B1-contaminated maize. Maize consumed in the Netherlands is imported from all parts of the world. Since processing will not affect the overall toxic effect, the fumonisin B1 intake is directly related to the quantity of maize consumed. Literature results concerning the occurrence of fumonisin B1 in a total of 349 samples of maize from 18 countries worldwide demonstrated the presence of this mycotoxin in 93% of the samples. The median fumonisin B1 contamination of all samples was 420 ng of fumonisin B1 per g of maize, and the average contamination level was 1,359 ng of fumonisin B1 per g of maize. Human intake of fumonisin B1 was estimated based on the maize consumption of all people in the Netherlands in 1992. A probability distribution was derived to allow estimation of the exposure of the population to fumonisin B1 intake in relation to maize intake. It showed that among those in the group considered to be at risk, people with gluten intolerance such as people with celiac or Dühring's disease, 37% are estimated to be exposed to an intake of at least 10(5) ng and 97% to an intake of at least 10(3) ng of fumonisin B1 per person per day. For all people in the Netherlands these percentages would be 1% and 49%, respectively.