2.3. Drying test
Maize kernels sub-samples were put in an oven (NSC9180,
So.Ge.Sa. srl, Potenza, Italy) working with forced air flow. Two
different temperature time combinations were considered in
addition to the untreated test: (i) 70 C 24 h; (ii) 95 C 9 h.
Water activity was measured both before and after the drying
process using AquaLab LITE (version 1.3 © Decagon devices Inc.,
WA, USA).
2.4. Incidence of infected kernels
Fifty kernels were randomly selected from each sample, surface
disinfected in 1% sodium hypochlorite solution for 2 min, then in
90% ethyl alcohol solution for 2 min, rinsed with sterile distilled
water and dried under a sterile hood. Then, kernels were plated in
Petri dishes with Potato Dextrose Agar (Oxoid LTD., Basingstoke,
Hampshire, England) and incubated at 25 C for 7 days.
After incubation, fungal strains developed from the kernels
were counted and identified at genera/section level based on their
phenotypic aspects. In particular, Fusarium, Aspergillus and Penicillium
spp. were taken into account. Incidence of infected kernels
was reported as the number of kernels with growing moulds rated
on the total number of plated kernels.