Chemical characterization of acid-pretreated renewable resources: effect of pretreatment time

Abstract

The production of value-added products from renewable resources by fermentation is very attractive. In this study, the effect of pretreatment time on the chemical composition of acid-pretreated tea processing waste (TPW), spent tea waste (STW), barley husk (BH), and rye bran (RB) was examined. After the pretreatment processes, reducing sugar concentration (RSC), phenolics (PHs), glucose (Glc), xylose (Xyl), arabinose (Ara), acetic acid (AA), D-glucuronic acid (D-GA), 5-hydroxymethyl furfural (HMF), 2-furaldehyde (2-F) and catalytic efficiency (E, g sugars/g inhibitors) were determined. Results indicated that maximum E values were 3.79, 4.57, 21.28, and 33.46 g/g when the pretreatment times were 50, 6, 30, and 1 min for TPW, STW, BH, and RB, respectively. At these E values, the levels of RSC, PHs, Glc, Xyl, Ara, AA, D-GA, and HMF were 22.85, 1.60, 2.76, 6.98, 4.26, 1.28, 0.62, and 0.81 g/L for TPW; 17.67, 1.12, 1.55, 4.80, 4.05, 0.91, 0.98, and 0.25 g/L for STW; 64.30, 1.25, 30.14, 16.05, 3.57, 0.85, 0.00, and 0.23 g/L for BH; and 66.62, 0.79, 35.21, 13.08, 4.44, 0.00, 0.00, and 0.80 g/L for RB, respectively. Consequently, the hydrolysates obtained after suitable pretreatment times can be evaluated as substrate after removal of the inhibitors formed when necessary.

Keywords:

• Raw materials
• dilute acid pretreatment
• pretreatment time
• chemical composition
• inhibitors

Disclosure statement

The authors declare that they have no conflict of interest in the publication.

Additional information

Funding

This study was supported by the Akdeniz University Research Foundation.