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Spent coffee ground has attracted increasing attentions since it contains many useful components such as polysaccharides, protein, lipid and bioactive compounds. The aim of this research is to enhance the enzymatic hydrolysis to release important sugars in spent coffee ground using different pretreatment methods. Spent coffee grounds were pretreated by alkali pretreatment, organosolv pretreatment and the combined process. The pretreated material was hydrolyzed by different commercial enzymes including Cellulast, Pectinex, Ultraflomax and Viscozyme. Monosaccharides, total phenolic content and antioxidant activity in the hydrolysate were measured and evaluated. The use of Viscozyme achieved the highest reducing sugar yield and showed the significant difference from other enzymes. Alkali and organosolv pretreatment demonstrated to improve the production of sugars. The alkali pretreatment followed by organosolv treatment effectively removed lignin, resulting in only 14% lignin in the pretreated sample. The maximum reducing sugar concentration reached 6120 mg/L through two-step pretreatment and subsequent enzymatic hydrolysis, corresponding to a yield of 161 mg sugar/g substrate. The spent coffee ground hydrolysate contained 2917 mg/L mannose, 1633 mg/L glucose and 957 mg/L galactose. Phenolic compounds were observed to be released during the enzymatic hydrolysis, giving a total phenolic content of 174.4 mg GAE/L and the SCG hydrolysate also showed an antioxidant capacity equivalent to 263.2 mg/L ascorbic acid after 120 h hydrolysis. This study demonstrated a scalable two-step pretreatment process to obtain important sugars including mannose, glucose, and galactose along with phenolic compounds for further industrial uses.
Andlar, M., Rezic, I., Oros, D., Kracher, D., Ludwig, R., Rezic, T. and Šanteka, B. (2016). Optimization of enzymatic sugar beet hydrolysis in a horizontal rotating tubular bioreactor. J Chem Technol Biotechnol. DOI 10.1002/jctb.5043
Choi, B., & Koh, E. (2017). Spent coffee as a rich source of antioxidative compounds. Food Science and Biotechnology, 26. doi: 10.1007/s10068-017-0144-9
Gama, R., Dyk, J. S. V, Pletschke, B. I. (2015). Optimisation of enzymatic hydrolysis of apple pomace for production of biofuel and biorefinery chemicals using commercial enzymes. 3 Biotech (2015) 5:1075–1087 DOI 10.1007/s13205-015-0312-7
Hu, X., Shi, Y., Zhang, P., Miao, M., Zhang, T., and Jiang, B (2016). D-Mannose: Properties, Production, and Applications: An Overview. Comprehensive Reviews in Food Science and Food Safety, 15:773-785. doi:10.1111/1541-4337.12211
Hudeckova, H., Neureiter, M., Obruca, S., Frühauf, S., Maroval, I. (2018). Biotechnological conversion of spent coffee grounds into lactic acid. Lett Appl Microbiol.
Jin, L. S., Salimi, Midhat, N., and Kamal, Syazni, Z. (2020). Optimization of Pretreatment and Enzymatic Hydrolysis of Spent Coffee Ground for the Production of Fermentable Sugar. Materials Science and Engineering, 743. doi:10.1088/1757-899X/743/1/012030
Liu, Y., Lua, Y., Liu, S. Q. (2021). The potential of spent coffee grounds hydrolysates fermented with Torulaspora delbrueckii and Pichia kluyveri for developing an alcoholic beverage: The yeasts growth and chemical compounds by yeast extracts. Current Research in Food Science 4 (2021) 489–498.
McNutt, J. & He, Q. (2018). Spent coffee grounds: A review on current utilization, Journal of Industrial and Engineering Chemistry. https://doi.org/10.1016/j.jiec.2018.11.054
Nguyen, Q. A., Cho, E. J., Lee, D. S., & Bae, H. J. (2019). Development of an advanced integrative process to create valuable biosugars including manno-oligosaccharides and mannose from spent coffee grounds. Bioresource technology, 272, 209–216. https://doi.org/10.1016/j.biortech.2018.10.018
Pesheva, D., Mitevb, D., Peevac, L., Peev, G., Valorization of spent coffee grounds – A new approach. Separation and Purification Technology 192: 271–277. http://dx.doi.org/10.1016/j.seppur.2017.10.021
Puri, M., Sharma, D., Barrow, C. J. (2012). Enzyme-assisted extraction of bioactives from plants. Trends in Biotechnology, 30 (1). doi:10.1016/j.tibtech.2011.06.014
Ravindran, R., Desmond, C., Jaiswal, S., Jaiswal, A. K. (2017). Optimisation of organosolv pretreatment for the extraction of polyphenols from spent coffee waste and subsequent recovery of fermentable sugars. Bioresource Technology. doi:10.1016/j.biteb.2018.05.009
Ravindran, R., Jaiswal, S., Abu-Ghannam, N., Jaiswal, A.K., Two-Step Sequential Pretreatment for the Enhanced Enzymatic Hydrolysis of Coffee Spent Waste, Bioresource Technology. doi: http://dx.doi.org/10.1016/j.biortech.2017.05.049
Sluiter, A., Hames, B., Ruiz, R., Scarlata, C., Sluiter, J., Templeton, D. (2005). Determination of Ash in Biomass. National Renewable Energy Laboratory.
Tang, S., Cao, Y., Xu, C., Wu, Y., , Li, L., Ye, P., Luo, Y., Gao, Y., Liao, Y., Yan, Q., and Cheng, X. (2020). One‐Step or Two‐Step Acid/Alkaline Pretreatments to Improve Enzymatic Hydrolysis and Sugar Recovery from Arundo Donax L. Energies 2020, 13, 948; doi:10.3390/en13040948
Trinh, T. P. L, Choi Y. S., Bae, H. J. (2018). Production of phenolic compounds and biosugars from flower resources via several extraction processes. Industrial Crops and Products, 125, 261-268. https://doi.org/10.1016/j.indcrop.2018.09.008
Wu, H., Zhang, W., Mu, W., 2019. Recent studies on the biological production of D-mannose. Appl Microbiol Biotechnol. 103, 8753–8761. DOI: 10.1007/s00253-019-10151-3
Wongsiridetchai, C., Chiangkham, W., Khlaihiran, N., Sawangwan, T., Wongwathanarat, P., Charoenrat, T., Chantorna, S. (2018). Alkaline pretreatment of spent coffee grounds for oligosaccharides production by mannanase from Bacillus sp. GA2(1). Agriculture and Natural Resources, 52: 222-227. https://doi.org/10.1016/j.anres.2018.09.012.