초록
<P><B>Abstract</B></P> <P>Grain sorghum [<I>Sorghum bicolor</I> (L.) Moench], a cost effective crop in semiarid regions, is an underestimated supplement to corn in starch based ethanol production. Twenty-three multi-seeded (<I>msd</I>) mutant sorghums and one wild type sorghum BTx623 were evaluated for ethanol production and chemical composition, pasting properties, and grain structure on ethanol yield and fermentation efficiency. Starch contents of the <I>msd</I> mutant sorghums ranged from 66.31 to 75.65%, while the starch content of BTx623 was 74.25%. The protein, fat and free amino nitrogen (FAN) contents of the <I>msd</I> mutant sorghums ranged from 9.44–13.33%, 0.81–2.03% and 873.2–925.4μg/g, respectively. The ethanol fermentation efficiency of <I>msd</I> mutant sorghums ranged from 87.29 to 92.54%. Taking into account that <I>msd</I> mutant sorghum can produce more than twice the amount of seed weight per panicle as wild type BTx623, <I>msd</I> mutant M2, the highest ethanol yield sample, could produce more than twice the amount of ethanol as wild type BTx623. All sorghum samples can be classified into three groups based fermentation rate: fast, medium and slow. For <I>msd</I> mutant sorghums with starch content higher than 71%, fermentation efficiencies were higher than 90%, and ethanol yields were higher than 470L/ton sorghum. In addition, the fermentation curves showed most of <I>msd</I> mutant sorghums took less time to complete fermentation (40–50h), indicating <I>msd</I> mutant sorghums have a great potential for biofuel application due to their high starch content, high fermentation efficiency, and final ethanol yield. Taking into account the best <I>msd</I> mutant sorghum that can produce more than twice the amount of seed weight as wild type sorghum, the best <I>msd</I> mutant could produce more than twice the amount of ethanol as wild type.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Best <I>msd</I> mutant sorghum produce more than twice ethanol than wild type per area. </LI> <LI> Ethanol fermentation efficiency of <I>msd</I> mutant sorghums ranged from 87.29 to 92.54%. </LI> <LI> <I>msd</I> mutant sorghums took less time to complete fermentation compared with wild type. </LI> <LI> <I>msd</I> mutant sorghums have a higher FAN content compared with wild type. </LI> </UL> </P>