초록
<P><B>Abstract</B></P><P>The bioconversion into ethanol of insect (<I>Sitophilus zeamais</I>), mold (<I>Aspergillus flavus</I>) and sprout-damaged maize and sorghum was investigated. Kernel test weight losses due to insect damage in maize were almost twice compared to sorghum (18.6 <I>vs.</I> 10.7%). All damaged kernels lost some of the starch and increased soluble sugars, ash and crude fiber. The mold-damaged sorghum contained approximately five times more FAN compared to the control. The sprout-damaged kernels contained the highest amounts of reducing sugars prior (11 g/L) to and at the end (146.5 g/L) of liquefaction with α-amylase. Ethanol yields based on the already damaged grain indicated that sprout-damaged kernels yielded similar amounts compared to sound kernels (381.1 vs. 382.6 L/ton and 376.6 vs. 374.8 L/ton of sorghum or maize respectively). The insect-damaged maize and sorghum have reduced ethanol yields compared with the controls (29 and 23% respectively), and this negative result was mainly due to dry matter losses during the inadequate storage. Despite differences in ethanol yield, all treatments have similar conversion efficiencies (76.1–89.9%) indicating the robustness of yeast facing biotic-damaged feedstocks. This research demonstrates that the use of already damaged insect, mold or sprouted kernels is feasible and a good alternative for biorefineries.</P> <P><B>Highlights</B></P><P>► Ethanol production with post harvest-damaged maize or sorghum was evaluated. ► Insect, mold and sprout-damaged maize and sorghum were used as treatments. ► All damaging treatments lost dry matter and increased its soluble sugar concentration ► Efficiencies were similar among samples and ethanol yields were around 380 L/ton.</P>