Impact of a Pretreatment Step on the Acidogenic Fermentation of Spent Coffee Grounds
Abstract
:1. Introduction
2. Materials and Methods
2.1. Substrate
2.2. SCG Pretreatments
2.3. Acidogenic Fermentation Assays
2.3.1. Inoculum
2.3.2. Experimental Set-Up
2.4. Analytical Methods
2.4.1. Determination of SCOAs, Monomeric Sugars, and Furans
2.4.2. Chemical Oxygen Demand (COD)
2.4.3. pH Measurement
2.4.4. Browning Intensity
2.4.5. Total Phenolic Compounds (TPC)
2.5. Calculations
2.5.1. COD Conversions
2.5.2. Acidification Degree
2.5.3. Yields and Productivities
2.5.4. Odd-to-Even Ratio of SCOAs
3. Results and Discussion
3.1. Pretreatments
3.1.1. Pretreatment Efficiency
3.1.2. Inhibitor Formation
3.2. Acidogenic Fermentation
3.2.1. SCOAs’ Production
3.2.2. Acidification Degree
3.2.3. Productivity
3.2.4. Odd-To-Even Carbon Ratio of SCOA
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Conflicts of Interest
References
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Pretreatment | pH | Sugars (g/L) | %Yield Sugars (gSugar/gSCG) | COD Extracted (gCOD/L) | %Yield Extracted (gCOD/gCOD) | TPC (mgGAE/g) | MRP | |
---|---|---|---|---|---|---|---|---|
ABS294 | ABS420 | |||||||
Acidic Hydrolysis 5% (AH 5%) | 1.38 | 1.95 | 5.20% | 4.15 | 2.25% | 21.5 | 0.438 | 0.223 |
Acidic Hydrolysis 10% (AH 10%) | 0.50 | 0.91 | 2.43% | 13.70 | 8.30% | 23.8 | 0.488 | 0.240 |
Basic Hydrolysis 5% (BH) | 12.26 | 0.01 | 0.03% | 11.12 | 6.74% | 30.6 | 0.831 | 0.710 |
Hydrothermal (HD) | 6.78 | 0.05 | 0.13% | 2.95 | 1.79% | 16.8 | 0.409 | 0.163 |
Ultrasounds (US) | 7.02 | 0.01 | 0.03% | 2.38 | 1.44% | 10.1 | 0.234 | 0.135 |
Microwave (MW) | 6.94 | 0.02 | 0.05% | 2.25 | 1.36% | 13.7 | 0.286 | 0.142 |
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Pereira, J.; de Melo, M.M.R.; Silva, C.M.; Lemos, P.C.; Serafim, L.S. Impact of a Pretreatment Step on the Acidogenic Fermentation of Spent Coffee Grounds. Bioengineering 2022, 9, 362. https://doi.org/10.3390/bioengineering9080362
Pereira J, de Melo MMR, Silva CM, Lemos PC, Serafim LS. Impact of a Pretreatment Step on the Acidogenic Fermentation of Spent Coffee Grounds. Bioengineering. 2022; 9(8):362. https://doi.org/10.3390/bioengineering9080362
Chicago/Turabian StylePereira, Joana, Marcelo M. R. de Melo, Carlos M. Silva, Paulo C. Lemos, and Luísa S. Serafim. 2022. "Impact of a Pretreatment Step on the Acidogenic Fermentation of Spent Coffee Grounds" Bioengineering 9, no. 8: 362. https://doi.org/10.3390/bioengineering9080362