“Liberation of Protein and Antioxidative Compound from Spent Coffee Ground Through Protein Hydrolysis” (2018) Pelita Perkebunan (a Coffee and Cocoa Research Journal), 34(2), pp. 95–103. Available at: https://www.ccrjournal.com/index.php/ccrj/article/view/318 (Accessed: 1 May 2026).