STUDIES ON THE REFRIGERATED STORAGE OF WHEAT (TRITICUM-AESTIVUM) .2. ERGOSTEROL, XANTHOMEGNIN, VIOMELLEIN AND BREVIANAMIDE-A AFTER INOCULATION WITH PENICILLIUM-VIRIDICATUM

Wheat seed was adjusted to 18, 20, 22, 24 and 26 % moisture content (m .c.), and stored for 240 days at 4 or 10-degrees-C following inoculati on with a strain of Penicillium viridicatum producing the toxins, xant homegnin (XA), viomellein (VIO), and brevianamide A (BA). Wheat kernel s were not sterilized before inoculation. The concentration of ergoste rol (ERG), a chemical indicator of fungal biomass, remained constant a t 18 % m.c./4-degrees-C, but increased under the other conditions. The time before a detectable increase of ERG concentration was higher and the rate of ERG production lower with decreasing moisture content and temperature. XA and BA were produced at both temperatures at 20-26 % m.c., VIO was produced at 22-26 % m.c./4-degrees-C and 20-26 % m.c./10 -degrees-C. The results suggest or indicate that the onset of XA, VIO and BA production (detection limits: 10, 15, and 0.1 mug/kg, respectiv ely) coincided with the onset of ERG production. Maximum toxin content s were lower with decreasing moisture content at both temperatures, bu t were similar at 4 and 10-degrees-C at 22-26 % m.c. It is concluded t hat wheat contaminated with P. viridatum should not be stored beyond t he onset of ergosterol production; maximum storage periods are recomme nded.