This study investigates the potential application of high powered ultrasonics as a liquefaction pretreatment of sugary-2 corn slurry. Ground sugary-2 corn ( Zea Mays L. ) slurry was treated with ultrasonics at 20kHz and amplitudes of 192-320 µ m pp (peak-to-peak) for 5, 10, 15, 20 and 40 seconds. After sonication, enzymes (Stargen TM 001) were added to the samples to hydrolyze the starch into fermentable sugars. It was found that the reducing sugar released in the treated samples were 6-fold higher than in the non-treated samples. Scanning electron microscopy images revealed that the sugary starch was partially gelatinized during sonication. This observation was confirmed by polarized-light microscopic images, where deformed “Maltese crosses” were found. The swelling rate of sonicated samples was nearly 66 times higher than when applying conventional heating. This result confirms better gelatinization capability of ultrasonics compared to conventional heating. The maximum relative net energy gain (additional chemically released energy) of the sonicated samples was at 5s of sonication time with a power setting between 248-330W. The findings in this study indicated ultrasonics as a promising pretreatment step in sugary-2 corn hydrolysis.
Available at: http://works.bepress.com/lawrence_johnson/3/