Vol.:(0123456789) 1 3 Waste and Biomass Valorization https://doi.org/10.1007/s12649-019-00830-7 SHORT COMMUNICATION Delignifcation of Aloe Vera Rind by Mild Acid Associated Microwave Pretreatment to Persuade Enhanced Enzymatic Saccharifcation Gunasekaran Rajeswari 1  · Balakrishnan Arutselvy 1  · Samuel Jacob 1 Received: 10 May 2019 / Accepted: 23 September 2019 © Springer Nature B.V. 2019 Abstract Aloe vera rind (AVR), a discarded solid biomass after extraction of gel fnds no commercial importance could serve as a potent lignocellulosic feedstock for bioethanol production that prerequisite an efcient pretreatment to remove the lignin (16.4%, w/w). In the present study, the impact of mild acid pretreatment on AVR by using microwave energy with varied power (160 W, 320 W and 480 W) and its efciency on saccharifcation was evaluated. Microwave acid pretreatment resulted in threefold decrease in recalcitrant lignin (5.58%, w/w) at 480 W than untreated AVR biomass. The efect of pretreatment on AVR biomass was characterized by various analytical techniques. X-Ray Difraction (XRD) patterns deciphered an increase in cellulose crystallinity (14.8%) of delignifed AVR biomass as compared to raw biomass (10.5%) and the extent of structural distortion after pretreatment was clearly indicated by Scanning Electron Microscopy (SEM). Fourier-Transform Infra-Red (FTIR) spectra revealed the disappearance of peak around 1241 cm −1 (C–O stretching) indicated the deacetyla- tion of hemicellulose after pretreatment. Gas Chromatography Mass Spectrometry (GC–MS) analysis of liquid hydrolysate obtained after pretreatment unveiled the presence of higher fraction of carboxylic acids, esters, aromatic and aliphatic hydrocarbons as a result of lignin oxidation. The maximum reducing sugar obtained by crude cellulase from the delignifed AVR biomass was found to be 296.8 ± 1.26 mg/g as compared to untreated AVR biomass (129.68 ± 2.34 mg/g). This study has shown the acid microwave pretreatment of AVR biomass could efectively improve the yield of fermentable sugars that are further used for ethanol production. Graphic Abstract Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12649-019-00830-7) contains supplementary material, which is available to authorized users. Extended author information available on the last page of the article