Affiliation:
1. Department of Biotechnology, Sangmyung University, Seoul 03016, Republic of Korea
Abstract
Mandarin peel (MP) has gained attention as a feedstock for flavonoid recovery via the extraction process based on the biorefinery concept, but residues remain after the extraction. Toward an integrated biorefinery concept, this study aimed to valorize extracted MP (eMP) by using it in bioethanol production. For efficient fermentable sugar production, the effect of enzymatic hydrolysis conditions on sugar conversion from eMP was investigated, and the results showed that combining cellulase and cellobiase resulted in a higher enzymatic glucose conversion (78.2%) than the use of the individual enzymes (37.5% and 45.6%). Pectinase played an essential role in enhancing enzymatic arabinose conversion, and the optimal conditions were determined to be pH 4 and 90 units of the three enzymes. Under optimal conditions, the sugar yield was 199 g glucose and 47 g arabinose/kg eMP, and the hydrolysate was used in bioethanol fermentation. The results showed that the bioethanol production was 3.78 g/L (73.9% yield), similar to the control medium (3.79 g/L; 74.2% yield), although the cell growth of the yeast was slightly delayed in the eMP hydrolysate medium. This study highlights the potential of eMP as a low-cost feedstock for sugar and bioethanol production.
Reference56 articles.
1. Gonzatto, M.P., and Santos, J.S. (2023). Introductory Chapter: World Citrus Production and Research. Citrus Research-Horticultural and Human Health Aspects, IntechOpen. Available online: https://www.intechopen.com/chapters/86388.
2. Converting citrus wastes into value-added products: Economic and environmently friendly approaches;Sharma;Nutrition,2017
3. Mahato, N., Sinha, M., Sharma, K., Koteswararao, R., and Cho, M.H. (2019). Modern extraction and purification techniques for obtaining high purity food-grade bioactive compounds and value-added co-products from citrus wastes. Foods, 8.
4. Green extraction of polyphenols from citrus peel by-products and their antifungal activity against Aspergillus flavus;Liu;Food Chem. X,2021
5. Šafranko, S., Ćorković, I., Jerković, I., Jakovljević, M., Aladić, K., Šubarić, D., and Jokić, S. (2021). Green extraction techniques for obtaining bioactive compounds from mandarin peel (Citrus unshiu var. Kuno): Phytochemical analysis and process optimization. Foods, 10.