کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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681381 | 1460023 | 2012 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Bioethanol production from raffinate phase of supercritical CO2 extracted Stevia rebaudiana leaves Bioethanol production from raffinate phase of supercritical CO2 extracted Stevia rebaudiana leaves](/preview/png/681381.png)
The extracts of Stevia rebaudiana are marketed as dietary supplements and utilized as natural sweetening agent in food products. Subsequent to extraction on industrial scale, large quantities of solid wastes are produced. The aim of this study was to investigate the bioconversion efficiency of supercritical CO2 extracted S. rebaudiana residues. Therefore, leaves were extracted with supercritical CO2 and ethanol mixture in order to obtain glycosides, then the raffinate phase was hydrolyzed by both dilute acid and various concentrations of cellulase and β-glucosidase cocktail. The maximum yield of reducing sugars reached 25.67 g/L under the optimal conditions of enzyme pretreatment, whereas 32.00 g/L was reached by consecutive enzymatic and acid hydrolyses. Bioethanol yield (20 g/L, 2.0% inoculum, 2 days) based on the sugar consumed was 45.55% corresponding to a productivity of 0.19 kg/m3h which demonstrates challenges to be utilized as a potential feedstock for the production of bioethanol.
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► Stevia rebaudiana leaves were extracted with supercritical CO2 and ethanol mixture.
► The raffinate phase was subjected to consecutive enzyme and acid hydrolyses.
► Overliming of the hydrolyzate proved to be effective yielding 45.55% bioethanol.
► An overall uncertainty of 1.31% was calculated for the whole process.
► The potential of S. rebaudiana leaves was presented using the biorefinery approach.
Journal: Bioresource Technology - Volume 120, September 2012, Pages 52–59