Prevention of ochratoxin A in commodities and likely effects of processing fractionation and animal feeds

Figures & data

Table I. Factors affecting cereals at harvest that may influence the formation and concentrations of OTA.

Factors
Weather before and at harvest
Time before drying
Efficiency of drying machinery
Physical state of grains
Temperature at harvest
Fungal competition
Cleanliness of harvesters and transport

Table II. Factors affecting cereals in store that may influence the formation and concentrations of OTA.

Factors
Cleanliness of storage containers
Absence of structural leaks
Condensation
Temperature
Time

Table III. P. verrucosum and OTA in residual grain and dust collected from grain stores in the UK.

Selected samples (kg)	P. verrucosum, log cfu g^−1	OTA, µg kg^−1
Barley and dust (100)	3.7	60
Dust and cereal debris	4.7	615
Barley (2)	5.3	133
Wheat debris	8.2	437
Mouldy wheat (20)	8.6	>1000

Table IV. Operations, conditions and effects that may affect concentrations of OTA in cereals.

Operations	Effects	Change in OTA
Cleaning and aspiration	Removes dust, fungal spores	−
Scouring	Takes of outer layers	−
Grading/sorting	Removes low quality grains	−
Milling	Grains separated into fractions	− and +
Steeping	Mycotoxin dissolves in aqueous solution	− or 0
Other ingredients	May modify chemical reactions	− or 0
Temperature	Reaction increases with temperature	−
pH	Effects reactivity	− or 0
Moisture	Increases hydrolysis	− or 0
Pressure and time	Breakdown will increase with time	− or 0
Enzyme action	May hydrolyse	− or 0
Residual mould	In situ formation of OTA	+
Ingestion of animal feed	Transfer to animal tissues and blood	−
OTA level in primary product: − = reduction, 0 = no change, + = increase.

Figure 1. The change in OTA concentrations during, cleaning, scouring, milling and bread making, starting level 6 µg kg⁻¹.

Figure 2. Distribution of OTA of a concentration of 42.2 µg kg⁻¹ in whole wheat in milled wheat fractions.

Figure 3. Breakdown of ochratoxin A during extrusion processing, moisture content in the range 17–20%.

Table V. OTA in animal feed ingredients UK 1992 (Scudamore et al. 1997), Limit of quantification 1 µg kg⁻¹.

Ingredients	Number of samples	% Positive	Maximum value, µg kg^−1
Wheat	50	20	17
Barley	45	27	102
Maize fractions	50	0	0
Rice bran	40	8	6
Cottonseed meal	21	0	0
Rapeseed meal	25	0	0
Sunflower meal	20	0	0
Olive pulp	5	0	0
Palm products	15	13	6
Soya meal	20	0	0
Dried peas/beans	15	7	33
Manioc	10	0	0

Scudamore , KA , Hetmanski , MT , Chan , HK and Collins , S . 1997 . Occurrence of mycotoxins in raw ingredients used for animal feeding stuffs in the UK in 1992 . Food Additives and Contaminants , 14 : 157 – 173 .

 PubMed Web of Science ®Google Scholar