Optimal Aqueous Extraction Conditions as A Green Technique for Recovery of Phenolic Antioxidants from Robusta Dried Coffee Pulp


  •   Thy Minh Kieu Tran

  •   Taiwo Akanbi

  •   Timothy Kirkman

  •   Minh Huu Nguyen

  •   Quan Van Vuong


Coffee pulp, a by-product of coffee processing, contains high level of flavonoids and other phenolic compounds. This by-product also contains high levels of other bioactive compounds such as chlorogenic acids and caffeine, which can be potentially recovered for further applications. This study used water as an inexpensive green solvent, for the maximum recovery of phenolics, major bioactive compounds and antioxidant capacity from coffee pulp. Recovery yield from optimal aqueous extraction was compared with organic solvent extraction. The results showed that temperature, extraction time and solid/solvent ratio significantly affected recovery yields from coffee pulp (P<0.05). Optimal aqueous extraction conditions were 100 °C, 60 min and the ratio of sample to solvent 1:100 g/mL. Under these optimal conditions, recovery yields were similar to those of 50% aqueous acetone extraction. Recovery yields were significantly higher than pure acetone, methanol and ethanol as well as methanol and ethanol in combination with water (50% v/v). Therefore, these optimal aqueous conditions are recommended for recovery of bioactive compounds from coffee pulp for further applications.

Keywords: Dried Coffee Pulp, Coffea Canephora, Robusta, Bioactive Compounds, Antioxidant Capacity, Phenolics, Hot Water, Solvent, Extraction, Conventional Extraction


Wang, Y. and C.-T. Ho, Polyphenolic Chemistry of Tea and Coffee: A Century of Progress. Journal of Agricultural and Food Chemistry, 2009. 57(18): p. 8109-8114.

Ramirez-Coronel, M.A., et al., Characterization and Estimation of Proanthocyanidins and Other Phenolics in Coffee Pulp (Coffea arabica) by Thiolysis−High-Performance Liquid Chromatography. Journal of Agricultural and Food Chemistry, 2004. 52(5): p. 1344-1349.

Roussos, S., I. Perraud-Gaime, and S. Denis, Biotechnological management of coffee pulp. Sulid State Fermentation, 1998: p. 151.

Ramirez‐Martinez, J.R., Phenolic compounds in coffee pulp: quantitative determination by HPLC. Journal of the Science of Food and Agriculture, 1988. 43(2): p. 135-144.

Tran, T.M.K., et al., Effects of drying on physical properties, phenolic compounds and antioxidant capacity of Robusta wet coffee pulp (Coffea canephora). Heliyon, 2020. 6(7): p. e04498.

Azwanida, N., A review on the extraction methods use in medicinal plants, principle, strength and limitation. Med. Aromat. Plants, 2015. 4(3): p. 3-8.

Clifford, M.N. and J.R. Ramirez-Martinez, Tannins in wet-processed coffee beans and coffee pulp. Food Chemistry, 1991. 40(2): p. 191-200.

Murthy, P.S. and M.M. Naidu, Recovery of Phenolic Antioxidants and Functional Compounds from Coffee Industry By-Products. Food and Bioprocess Technology, 2012. 5(3): p. 897-903.

Bresciani, L., et al., Phenolic composition, caffeine content and antioxidant capacity of coffee silverskin. Food Research International, 2014. 61: p. 196-201.

Wang, J., et al., Optimisation of ultrasound-assisted extraction of phenolic compounds from wheat bran. Food Chemistry, 2008. 106(2): p. 804-810.

Rostagno, M.A., M. Palma, and C.G. Barroso, Ultrasound-assisted extraction of soy isoflavones. Journal of Chromatography A, 2003. 1012(2): p. 119-128.

Ameer, K., H.M. Shahbaz, and J.H. Kwon, Green extraction methods for polyphenols from plant matrices and their byproducts: A review. Comprehensive Reviews in Food Science and Food Safety, 2017. 16(2): p. 295-315.

Vuong, Q.V., et al., Optimizing conditions for the extraction of catechins from green tea using hot water. Journal of separation science, 2011. 34(21): p. 3099-3106.

Geremu, M., Y.B. Tola, and A. Sualeh, Extraction and determination of total polyphenols and antioxidant capacity of red coffee (Coffea arabica L.) pulp of wet processing plants. Chemical and Biological Technologies in Agriculture, 2016. 3(1): p. 25.

Moon, J.-K., H.S. Yoo, and T. Shibamoto, Role of Roasting Conditions in the Level of Chlorogenic Acid Content in Coffee Beans: Correlation with Coffee Acidity. Journal of Agricultural and Food Chemistry, 2009. 57(12): p. 5365-5369.

[16] Vuong, Q.V., et al., Effect of Drying Conditions on Physicochemical and Antioxidant Properties of V itex agnus‐castus Leaves. Journal of food processing and preservation, 2015. 39(6): p. 2562-2571.

Vergara-Salinas, J.R., et al., Effects of temperature and time on polyphenolic content and antioxidant activity in the pressurized hot water extraction of deodorized thyme (Thymus vulgaris). Journal of agricultural and food chemistry, 2012. 60(44): p. 10920-10929.

Hossain, M., et al., Optimisation of accelerated solvent extraction of antioxidant compounds from rosemary (Rosmarinus officinalis L.), marjoram (Origanum majorana L.) and oregano (Origanum vulgare L.) using response surface methodology. Food Chemistry, 2011. 126(1): p. 339-346.

Jeszka-Skowron, M., et al., Chlorogenic acids, caffeine content and antioxidant properties of green coffee extracts: influence of green coffee bean preparation. European Food Research and Technology, 2016. 242(8): p. 1403-1409.

Andueza, S., et al., Influence of extraction temperature on the final quality of espresso coffee. Journal of the Science of Food and Agriculture, 2003. 83(3): p. 240-248.

Kha, T.C. and M.H. Nguyen, Extraction and isolation of plant bioactives. Plant bioactive compounds for pancreatic cancer prevention and treatment, 2014: p. 117-144.

Pham, H., et al., Effect of extraction solvents and drying methods on the physicochemical and antioxidant properties of Helicteres hirsuta Lour. Leaves. Technologies, 2015. 3(4): p. 285-301.

Saifullah, M., et al., Comparison of conventional extraction technique with ultrasound assisted extraction on recovery of phenolic compounds from lemon scented tea tree (Leptospermum petersonii) leaves. Heliyon, 2020. 6(4): p. e03666.

Vuong, Q.V., et al., Effect of extraction conditions on total phenolic compounds and antioxidant activities of Carica papaya leaf aqueous extracts. Journal of Herbal Medicine, 2013. 3(3): p. 104-111.

Alu’datt, M.H., et al., Optimisation and characterisation of various extraction conditions of phenolic compounds and antioxidant activity in olive seeds. Natural product research, 2011. 25(9): p. 876-889.

Pinelo, M., et al., Effect of solvent, temperature, and solvent-to-solid ratio on the total phenolic content and antiradical activity of extracts from different components of grape pomace. Journal of agricultural and food chemistry, 2005. 53(6): p. 2111-2117.

Ollanketo, M., et al., Extraction of sage (Salvia officinalis L.) by pressurized hot water and conventional methods: antioxidant activity of the extracts. European Food Research and Technology, 2002. 215(2): p. 158-163.

Pham, H.N.T., et al., Effect of extraction solvents and drying methods on the physicochemical and antioxidant properties of helicteres hirsuta lour. leaves. Technologies, 2015. 3(4): P. 285-301.

Thaipong K, Boonprakob U, Crosby K, Cisneros-Zevallos L, Byrne DH. Comparison of ABTS, DPPH, FRAP, and ORAC assays for estimating antioxidant activity from guava fruit extracts. Journal of food composition and analysis. 2006 Sep 1;19(6-7):669-75.

Benzie IF, Strain JJ. The ferric reducing ability of plasma (FRAP) as a measure of “antioxidant power”: the FRAP assay. Analytical biochemistry. 1996 Jul 15;239(1):70-6.


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How to Cite
Tran, T.M.K., Akanbi, T., Kirkman, T., Nguyen, M.H. and Vuong, Q.V. 2020. Optimal Aqueous Extraction Conditions as A Green Technique for Recovery of Phenolic Antioxidants from Robusta Dried Coffee Pulp. European Journal of Engineering and Technology Research. 5, 9 (Sep. 2020), 1069-1074. DOI:https://doi.org/10.24018/ejers.2020.5.9.2116.