Pretreatment of macadamia nut shells with ionic liquids facilitates both mechanical cracking and enzymatic hydrolysis
Journal
ACS Sustainable Chemistry and Engineering
Journal Volume
3
Journal Issue
5
Start Page
992
End Page
999
ISSN
21680485
Date Issued
2015
Author(s)
Abstract
The effect of ionic liquids upon the mechanical and (bio)chemical integrity of macadamia nut shells (from Macadamia integrifolia) has been investigated. Whole macadamia nuts-in-shell are notoriously difficult to crack, and the Australian macadamia nut shells used in this study required 2240 ± 430 N of force to crack. Ionic liquids were screened for their solubility values, with 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) able to dissolve 5.5 ± 0.5 wt % macadamia nut shell. Treatment with small quantities of [Emim][OAc] resulted in weakened whole nut-in-shells that could be cracked with only ca. 46% of the displacement (0.67 ± 0.16 mm), ca. 34% of the force (760 ± 240 N) and ca. 15% of the energy (0.25 ± 0.10 J per shell) relative to no treatment. Further treatment by dissolution and precipitation of macadamia nut shell, followed by enzymatic hydrolysis with cellulase, resulted in the release of 80 ± 15% of the expected glucose content, relative to 1.3 ± 1.0% before any pretreatment. © 2015 American Chemical Society.
Subjects
Facilitated biomass processing
Ionic liquids
Macadamia
Nuts-in-shell
Weakening biomass
Publisher
American Chemical Society
Type
journal article