![]() In addition to achieving high extraction yields, these techniques present operational flexibility, and low capital investment, energy consumption, and operational costs (Wu et al., 2009). Importantly, it enables the simultaneous extraction of water-soluble (i.e., proteins, polyphenols, and carbohydrates) and insoluble (i.e., lipids) compounds from different matrices such as soybeans (De Moura et al., 2009), peanuts (Jiang et al., 2010), sunflower (de Aquino et al., 2019), and yellow mustard (Tabtabaei & Diosady, 2013). The use of aqueous (AEP) and enzymatic extraction processes (EAEP) is an effective green extraction approach that can address the low extraction yields from mechanical pressing and the subsequent use of flammable solvents to further defat the residual cake. ![]() Among the wide range of plant-based proteins currently being evaluated for industrial applications, green coffee protein is one of the least evaluated by current research, evidencing a knowledge gap about the impact of extraction and fractionation strategies on their physicochemical and functional properties, a required step to identify potential applications for green coffee protein. The use of proteins as ingredients in food systems is of key importance as they possess numerous functional properties (e.g., gelation, solubility, emulsification, and foaming capacity) (Zayas, 1997) of interest for the production of nutritious and functional foods. Therefore, current extraction practices can hinder the potential use of this fraction for cosmetic and food applications (Oliveira et al., 2019b). This not only raises environmental/safety concerns but can negatively affect the quality of the extracted oil (Chemat et al., 2019). Therefore, it generates a cake byproduct containing proteins and unextracted lipids, the latter requiring subsequent removal by the use of neurotoxic/flammable solvents. Green coffee oil is frequently extracted by cold mechanical pressing, a process known for having low extraction efficiency for low oil content matrices such as coffee beans. Furthermore, growing interest in the production and utilization of green coffee protein extracts has been recently fueled by the whole plant-based protein concept, which brings additional benefits associated with the presence of soluble phytoantioxidants (Applied Food Sciences, 2019 Oliveira et al., 2019a Prandi et al., 2021 Siegner, 2019). However, because of the potential health benefits associated with green coffee oil such as antioxidant activity, protection against damage caused by UVB radiation, regeneration of lipids from the corneum stratum, besides the good emollient properties (Voytena et al., 2017), coffee beans have also been redirected to the oil industry. These findings revealed the impact of extraction conditions on the extractability and structural modifications altering the functionality of green coffee proteins and the synergistic impact of extraction and demulsification strategies on the recovery of the extracted oil, paving the way for the development of structure–function processes to effectively produce green coffee proteins with desired functionality.Ĭoffee beans have been primarily used to produce beverages worldwide. However, proteolysis did reduce the foaming properties of the hydrolysates compared with larger molecular weight proteins. Proteolysis did not alter the high in vitro digestibility of green coffee proteins (up to 99%) or their emulsifying properties at most pH values evaluated. The physicochemical changes observed due to proteolysis resulted in the formation of emulsions with reduced resistance against enzymatic and chemical demulsification strategies, enhancing the recovery of the extracted oil (48.6–51.0%). Proteolysis resulted in the release of smaller proteins with reduced surface hydrophobicity and higher solubility at acidic pH (3.0–5.0). Enzymatic extraction increased protein extractability by ~13% while achieving similar oil extractability when not using enzymes (55%). To replace the use of flammable solvents and enable the simultaneous extraction of lipids and proteins from green coffee beans at reduced water usage, a multistage countercurrent extraction process was scaled up from 0.05 to 1.14 kg and evaluated regarding protein and oil extractability, physicochemical and functional properties of the extracted protein, and oil recovery. Green coffee processing has been hindered by low oil extraction yields from mechanical pressing and the need of using flammable and hazardous solvents for defatting the protein-rich cake before subsequent protein extraction.
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