Chemical and Physical Properties

Zearalenone is a white crystalline compound, which exhibits blue-green fluorescence when excited by long-wavelength UV light (360 nm) and a more intense green fluorescence when excited by short-wavelength UV light (260 nm). In methanol,

HO O CH3

HO O CH3

zearalenon

O CH3

O CH3

zearalenon

OH O CH3

zearalanon

OH O CH3

O CH3

O CH3

b zearalanol

a zearalanol

OH O CH3

a zearalanol

OH O CH3

Fig. 15.1 The chemical structures of zearalenone and its derivatives b zearalanol

OH O CH3

OH O CH3

a zearalenol b zearalenol

Fig. 15.1 The chemical structures of zearalenone and its derivatives

UV absorption maxima occur at 236, 274 and 316 nm. The molecular formula of zearalenone is C18H22O5, its molecular weight is 318.4 g/mol and its melting point is 162-163°C (Blackwell et al. 1985; Josephs et al. 2003). The maximum fluorescence in ethanol occurs with irradiation at 314 nm and with emission at 450 nm. Its solubility in water is about 0.002 g/100 ml. In an aqueous solution of inositol, the presence of zearalenone can change the crystal structure of this alcohol, which indicates the possibility of interaction between both substances (our observations). Moreover, zearalenone is slightly soluble in hexane and progressively more so in benzene, ace-tonitrile, methylene chloride, methanol, ethanol and acetone. However, it is readily soluble in aqueous alkali.

In fungal cultures a number of closely related metabolites are formed, but there is only limited evidence that these occur in foodstuffs, although there is experimental evidence for some transmission of zearalenone and a- and b-zearalenols into the milk of sheep, cows and pigs fed with these substances at high concentrations. Zearalenone does not degrade at high temperatures (Zinedine et al. 2007), but may

be partly decomposed by heat. Approximately 60% of zearalenone remained unchanged in bread while about 50% survives in the production of noodles. Extrusion cooking may result in significant reduction of zearalenone with higher reductions of this substance at 120-140°C than at 160°C (Mateo et al. 2002).

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