|Chen, Min-hsu - UNIVERSITY OF ILLINOIS|
|Vincent, Michael - UNIVERSITY OF ILLINOIS|
|Below, Frederick - UNIVERSITY OF ILLINOIS|
|Singh, Vijay - UNIVERSITY OF ILLINOIS|
Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2014
Publication Date: 9/1/2014
Publication URL: http://handle.nal.usda.gov/10113/62200
Citation: Chen, M., Dien, B.S., Vincent, M.L., Below, F.E., Singh, V. 2014. Effect of harvest maturity on carbohydrates for ethanol production from sugar enhanced temperate x tropical maize hybrid. Industrial Crops and Products. 60:266-272.
Interpretive Summary: Tropical maize is being developed as a sugar crop for production in northern climates. Tropical maize has characteristics that potentially give it advantages over other sugar crops. It could be superior to sugar cane because it is adapted to lower temperatures and it is potentially better than sweet sorghum because its development can take advantage of all the genetics and agronomics that have been developed for grain corn. In this study, sugar crop was evaluated for carbohydrates at multiple harvest maturities to find the optimal time for harvest for maximum sugar yield. The soluble sugars, starch, and cellulose were each converted to ethanol separately using distillers yeast at each maturity. Its highest yield was estimated to be 624.7 gal of ethanol per acre. These results will be of interest to ethanol and corn refiners and possibly farmers interested in alternate crops.
Technical Abstract: A northern adapted sugar maize (Zea mays L.) hybrid was bred by crossing temperate x tropical maize for bioethanol production. Temperate x tropical maize (TTM) has a prolonged vegetative growth and accumulates more sugar in the stalk compared to its respective tropical and temperature parents. In this study, the sugar concentration in the stalk was further increased by preventing pollination by shoot bagging (covering) ears. It was observed that starch content was eliminated and sugar content increased to 30.1% w/w in the stalks. The whole plant biomass (grain, sugars and stover) was evaluated for ethanol production. Ethanol produced from sugars and starch was comparable from milk (R3) to dent (R5) reproductive growth stages between pollinated and non-pollinated TTM, indicating that soluble sugar contents increased correspondingly with decreased starch contents. Temperate x tropical maize samples from both pollinated and non-pollinated treatments had high extractives. Glucan and xylan percentages were increased in non-pollinated extractive free samples. Ethanol produced from cellulosic material was similar for both treatments. The total ethanol yield (from starch, sugar and stover) was comparable from milk (R3) to dent (R5) stages and ranged from 0.20 to 0.22 g/g biomass. The pollinated TTM produced higher biomass in the field and resulted in 624.7 gallons of ethanol per acre of land. Future research in TTM could be focused on increasing biomass yield of non-pollinated TTM.