Optimizing of acidic and alkaline pretreatments for enhanced sugar release of coffee silverskin: a taguchi method approach

Abstract

Coffee by-products are promising reservoirs of antioxidants and fermentable sugars. Coffee silverskin (CSS) is a significant by-product of coffee bean roasting. In this study, glucose release from CSS was optimized to investigate the pretreatment parameters using the Taguchi method. For this purpose, four different acids (HCl, H2SO4, HNO3, and CH3COOH) and two alkalis (NaOH and KOH) were tested. The factors were acid/alkali type and amount (1, 2, 3, and 4%), CSS amount (2.5, 7.5, 12.5, and 17.5%), and treatment time (15, 30, 45, and 60 min). Sixteen experimental runs were performed using the L16 orthogonal array. The conditions under which maximum glucose release was obtained and the effects of these conditions on the process were examined. The maximum glucose yield (Yg= 0.037 gglucose/gbiomass) was obtained by autoclaving a 4% (v/v) HCl solution containing 17.5% CSS (w/v) for 60 min. This study evaluated the effectiveness of pre-enzymatic CSS treatments to produce fermentable sugars that are valuable for various industrial applications.

Keywords

• Glucose
• Optimization
• Taguchi
• Coffee by-products
• Waste management

References

1. Alavi-Borazjani, S. A., da Cruz Tarelho, L. A., & Capela, M. I. (2021). Parametric optimization of the dark fermentation process for enhanced biohydrogen production from the organic fraction of municipal solid waste using Taguchi method. International Journal of Hydrogen Energy, 46(41), 21372-21382. https://doi.org/10.1016/j.ijhydene.2021.04.017
2. Andrade Mota, D., dos Santos Barbosa, M., Kleveston Schneider, J., Silva Lima, Á., M Pereira, M., Canielas Krause, L., & Faria Soares, C. M. (2021). Potential use of crude coffee silverskin oil in integrated bioprocess for fatty acids production. Journal of the American Oil Chemists' Society, 98(5), 519-529. https://doi.org/10.1002/aocs.12472
3. Batista Meneses, D., Montes de Oca-Vásquez, G., Vega-Baudrit, J. R., Rojas-Álvarez, M., Corrales-Castillo, J., & Murillo-Araya, L. C. (2022). Pretreatment methods of lignocellulosic wastes into value-added products:recent advances and possibilities. Biomass Conversion and Biorefinery, 1-18. https://doi.org/10.1007/s13399-020-00722-0
4. Chen, L., Chen, R., & Fu, S. (2015). FeCl3 pretreatment of three lignocellulosic biomass for ethanol production. ACS Sustainable Chemistry & Engineering, 3(8), 1794-1800. https://doi.org/10.1021/acssuschemeng.5b00377
5. Conde, T., & Mussatto, S. I. (2016). Isolation of polyphenols from spent coffee grounds and silverskin by mild hydrothermal pretreatment. Preparative Biochemistry and Biotechnology, 46(4), 406-409. http://doi.org/10.1080/10826068.2015.1084514
6. Corrêa, C. L., Penha, E. M., Freitas-Silva, O., Luna, A. S., & Gottschalk, L. M. (2021). Enzymatic technology application on coffee co-products: a review. Waste and Biomass Valorization, 12, 3521-3540. https://doi.org/10.1007/s12649-020-01208-w
7. Dadi, D., Beyene, A., Simoens, K., Soares, J., Demeke, M. M., Thevelein, J. M., Bernaerts, K., Luis, P., & Van der Bruggen, B. (2018). Valorization of coffee byproducts for bioethanol production using lignocellulosic yeast fermentation and pervaporation. International journal of environmental science and technology, 15, 821-832. https://doi.org/10.1007/s13762-017-1440-x
8. del Pozo, C., Rego, F., Yang, Y., Puy, N., Bartrolí, J., Fàbregas, E., & Bridgwater, A. V. (2021). Converting coffee silverskin to value-added products by a slow pyrolysis-based biorefinery process. Fuel Processing Technology, 214, 106708. https://doi.org/10.1016/j.fuproc.2020.106708

9. Dutra, E. D., Santos, F. A., Alencar, B. R. A., Reis, A. L. S., de Souza, R. D. F. R., Aquino, K. A. D. S., Morais, Jr. M. A., & Menezes, R. S. C. (2018). Alkaline hydrogen peroxide pretreatment of lignocellulosic biomass: status and perspectives. Biomass Conversion and Biorefinery, 8, 225-234. https://doi.org/10.1007/s13399-017-0277-3
10. Ebrahimian, F., Denayer, J. F., Mohammadi, A., Khoshnevisan, B., & Karimi, K. (2023). A critical review on pretreatment and detoxification techniques required for biofuel production from the organic fraction of municipal solid waste. Bioresource technology, 368, 128316. https://doi.org/10.1016/j.biortech.2022.128316
11. Garcia, C. V., & Kim, Y. T. (2021). Spent coffee grounds and coffee silverskin as potential materials for packaging: A review. Journal of Polymers and the Environment, 29(8), 2372-2384. https://doi.org/10.1007/s10924-021-02067-9
12. Gondim, F. F., Rodrigues, J. G. P., Tienne, L. G. P., de Oliveira Aguiar, V., & de Fátima Vieira Marques, M. (2024). Alkaline pretreatment and steam explosion process on coffee silverskin and incorporation of cellulose fibers in poly (butylene adipate‐co‐terephthalate). Journal of Applied Polymer Science, 141(17), e55287. https://doi.org/10.1002/app.55287
13. Gundupalli, M. P., Sahithi, S. A., Jayex, E. P., Asavasanti, S., Yasurin, P., Cheng, Y. S., & Sriariyanun, M. (2022). Combined effect of hot water and deep eutectic solvent (DES) pretreatment on a lignocellulosic biomass mixture for improved saccharification efficiency. Bioresource Technology Reports, 17, 100986. https://doi.org/10.1016/j.biteb.2022.100986
14. Hijosa-Valsero, M., Garita-Cambronero, J., Paniagua-García, A. I., & Díez-Antolínez, R. (2018). Biobutanol production from coffee silverskin. Microbial cell factories, 17, 1-9. https://doi.org/10.1186/s12934-018-1002-z
15. Hoang, A. T., Nizetic, S., Ong, H. C., Chong, C. T., & Atabani, A. E. (2021). Acid-based lignocellulosic biomass biorefinery for bioenergy production: Advantages, application constraints, and perspectives. Journal of Environmental Management, 296, 113194. https://doi.org/10.1016/j.jenvman.2021.113194
16. International Coffee Organization, (2023). https://icocoffee.org/documents/cy2023-24/Coffee_Report_and_Outlook_December_2023_ICO.pdf
17. Jin, L. S., Salimi, M. N., & Kamal, S. Z. (2020). Optimization of pretreatment and enzymatic hydrolysis of spent coffee ground for the production of fermentable sugar. In IOP Conference Series: Materials Science and Engineering (Vol. 743, No. 1, p. 012030). IOP Publishing. https://doi.org/10.1088/1757-899X/743/1/012030
18. Lee, K. H., Jang, Y. W., Lee, J., Kim, S., Park, C., & Yoo, H. Y. (2021). Statistical optimization of alkali pretreatment to improve sugars recovery from spent coffee grounds and utilization in lactic acid fermentation. Processes, 9(3), 494. https://doi.org/10.3390/pr9030494
19. Li, X., Shi, Y., Kong, W., Wei, J., Song, W., & Wang, S. (2022). Improving enzymatic hydrolysis of lignocellulosic biomass by bio-coordinated physicochemical pretreatment—A review. Energy Reports, 8, 696-709. https://doi.org/10.1016/j.egyr.2021.12.015
20. Loow, Y. L., Wu, T. Y., Md. Jahim, J., Mohammad, A. W., & Teoh, W. H. (2016). Typical conversion of lignocellulosic biomass into reducing sugars using dilute acid hydrolysis and alkaline pretreatment. Cellulose, 23, 1491-1520. https://doi.org/10.1007/s10570-016-0936-8
21. Mirzoyan, S., Aghekyan, H., Vanyan, L., Vassilian, A., & Trchounian, K. (2022). Coffee silverskin as a substrate for biobased production of biomass and hydrogen by Escherichia coli. International Journal of Energy Research, 46(15), 23110-23121. https://doi.org/10.1002/er.8612
22. Morales-Martínez, J. L., Aguilar-Uscanga, M. G., Bolaños-Reynoso, E., & López-Zamora, L. (2021). Optimization of chemical pretreatments using response surface methodology for second-generation ethanol production from coffee husk waste. BioEnergy Research, 14(3), 815-827. https://doi.org/10.1007/s12155-020-10197-6
23. Murthy, P. S., & Naidu, M. M. (2012). Production and application of xylanase from Penicillium sp. utilizing coffee by-products. Food and Bioprocess Technology, 5, 657-664. https://doi.org/10.1007/s11947-010-0331-7
24. Murthy, P. S., Madhava Naidu, M., & Srinivas, P. (2009). Production of α‐amylase under solid‐state fermentation utilizing coffee waste. Journal of Chemical Technology & Biotechnology: International Research in Process, Environmental & Clean Technology, 84(8), 1246-1249. https://doi.org/10.1002/jctb.2142
25. Mussatto, S. I., Ballesteros, L. F., Martins, S., Maltos, D. A., Aguilar, C. N., & Teixeira, J. A. (2013). Maximization of fructooligosaccharides and β-fructofuranosidase production by Aspergillus japonicus under solid-state fermentation conditions. Food and Bioprocess Technology, 6, 2128-2134. https://doi.org/10.1007/s11947-012-0873-y
26. Mussatto, S. I., Machado, E. M., Carneiro, L. M., & Teixeira, J. A. (2012). Sugars metabolism and ethanol production by different yeast strains from coffee industry wastes hydrolysates. Applied Energy, 92, 763-768. https://doi.org/10.1016/j.apenergy.2011.08.02
27. Nava-Valente, N., Del Ángel-Coronel, O. A., Atenodoro-Alonso, J., & López-Escobar, L. A. (2023). Effect of thermal and acid pre-treatment on increasing organic loading rate of anaerobic digestion of coffee pulp for biogas production. Biomass Conversion and Biorefinery, 13(6), 4817-4830. https://doi.org/10.1007/s13399-021-01529-3
28. Niglio, S., Procentese, A., Russo, M. E., Sannia, G., & Marzocchella, A. (2017). Ultrasound-assisted dilute acid pretreatment of coffee silverskin for biorefinery applications. Chemical Engineering Transactions, 57, 109-114. https://doi.org/10.3303/CET1757019
29. Niglio, S., Procentese, A., Russo, M. E., Sannia, G., & Marzocchella, A. (2019). Investigation of enzymatic hydrolysis of coffee silverskin aimed at the production of butanol and succinic acid by fermentative processes. BioEnergy research, 12, 312-324. https://doi.org/10.1007/s12155-019-09969-6
30. Niglio, S., Procentese, A., Russo, M. E., Sannia, G., & Marzocchella, A. (2020). Combined pretreatments of coffee silverskin to enhance fermentable sugar yield. Biomass Conversion and Biorefinery, 10, 1237-1249. https://doi.org/10.1007/s13399-019-00498-y
31. Ojo, A. O. (2023). An overview of lignocellulose and its biotechnological importance in high-value product production. Fermentation, 9(11), 990. https://doi.org/10.3390/fermentation9110990
32. Pourfarzad, A., Mahdavian-Mehr, H., & Sedaghat, N. (2013). Coffee silverskin as a source of dietary fiber in bread-making: Optimization of chemical treatment using response surface methodology. LWT-Food Science and Technology, 50(2), 599-606. http://dx.doi.org/10.1016/j.lwt.2012.08.001
33. Procentese, A., & Rehmann, L. (2018). Fermentable sugar production from a coffee processing by-product after deep eutectic solvent pretreatment. Bioresource technology reports, 4,174-180. https://doi.org/10.1016/j.biteb.2018.10.012
34. Procentese, A., Raganati, F., Navarini, L., Olivieri, G., Russo, M. E., & Marzoccchella, A. (2018b). Coffee silverskin as a renewable resource to produce butanol and isopropanol. Chem. Eng. Trans, 64.
35. Procentese, A., Raganati, F., Olivieri, G., Russo, M. E., & Marzocchella, A. (2019). Combined antioxidant-biofuel production from coffee silverskin. Applied microbiology and biotechnology, 103, 1021-1029. https://doi.org/10.1007/s00253-018-9530-3
36. Procentese, A., Raganati, F., Olivieri, G., Russo, M. E., Rehmann, L., & Marzocchella, A. (2018a). Deep Eutectic Solvents pretreatment of agro-industrial food waste. Biotechnology for biofuels, 11, 1-12. https://doi.org/10.1186/s13068-018-1034-y
37. Pulidindi, I. N., & Kim, T. H. (2018). Conversion of levulinic acid from various herbaceous biomass species using hydrochloric acid and effects of particle size and delignification. Energies, 11(3), 621. https://doi.org/10.3390/en11030621
38. Rabemanolontsoa, H., & Saka, S. (2016). Various pretreatments of lignocellulosics. Bioresource technology, 199, 83-91. http://doi.org/10.1016/j.biortech.2015.08.029
39. Ravindran, R., Jaiswal, S., Abu-Ghannam, N., & Jaiswal, A. K. (2017). Two-step sequential pretreatment for the enhanced enzymatic hydrolysis of coffee spent waste. Bioresource technology, 239, 276-284. http://doi.org/10.1016/j.biortech.2017.05.049
40. Renaudie, M., Dumas, C., Vuilleumier, S., & Ernst, B. (2022). New way of valorization of raw coffee silverskin: Biohydrogen and acetate production by dark fermentation without exogenous inoculum. Bioresource Technology Reports, 17, 100918. https://doi.org/10.1016/j.biteb.2021.100918
41. Smyrnakis, G., Stamoulis, G., Palaiogiannis, D., Chatzimitakos, T., Athanasiadis, V., Lalas, S. I., & Makris, D. P. (2023). Recovery of Polyphenolic Antioxidants from Coffee Silverskin Using Acid-Catalyzed Ethanol Organosolv Treatment. ChemEngineering, 7(4), 72. https://doi.org/10.3390/chemengineering7040072
42. Soontornchaiboon, W., Kim, S. M., & Pawongrat, R. (2016). Effects of alkaline combined with ultrasonic pretreatment and enzymatic hydrolysis of agricultural wastes for high reducing sugar production. Sains Malaysiana, 45(6), 955-962.
43. Tan, J., Li, Y., Tan, X., Wu, H., Li, H., & Yang, S. (2021). Advances in pretreatment of straw biomass for sugar production. Frontiers in chemistry, 9, 696030. https://doi.org/10.3389/fchem.2021.696030
44. Toquero, C., & Bolado, S. (2014). Effect of four pretreatments on enzymatic hydrolysis and ethanol fermentation of wheat straw. Influence of inhibitors and washing. Bioresource technology, 157, 68-76. http://doi.org/10.1016/j.biortech.2014.01.090
45. Zborowska, M., Waliszewska, H., Waliszewska, B., Borysiak, S., Brozdowski, J., & Stachowiak-Wencek, A. (2021). Conversion of carbohydrates in lignocellulosic biomass after chemical pretreatment. Energies, 15(1), 254. https://doi.org/10.3390/en15010254
46. Zhang, K., Pei, Z., & Wang, D. (2016). Organic solvent pretreatment of lignocellulosic biomass for biofuels and biochemicals: A review. Bioresource technology, 199, 21-33. http://doi.org/10.1016/j.biortech.2015.08.102
47. Zhang, Y., Di, X., Xu, J., Shao, J., Qi, W., & Yuan, Z. (2019). Effect of LHW, HCl, and NaOH pretreatment on enzymatic hydrolysis of sugarcane bagasse: sugar recovery and fractal-like kinetics. Chemical engineering communications, 206(6), 772-780. https://doi.org/10.1080/00986445.2018.1525365