Reni Yuniarti, P. Hermanus Kristian, Andar Tito Aritonang, Nur Maulana Syahadat, Adel Lia Rahma Dani, Rani Hantika Putri, Yehezkiel Kacaribu, Deviany Deviany, Masayu Nur Ulfa, Misbahudin Alhanif, Feerzet Achmad
Coffee pulp waste, a by-product of the coffee industry, is often considered low-value and poses environmental concerns if not properly managed. However, its high pectin content presents potential for use in producing edible films. This study investigated the effect of citric acid concentration (0.1, 0.5, and 1 M) during extraction on the yield and characteristics of the pectin produced. The results showed that the higher the citric acid concentration, the higher the pectin yield, ranging from 7.7% at 0.1 M to 22.13% at 1 M. However, higher acid concentration resulted in decreases in equivalent weight (235.59±11.76 to 93.53±3.71 mg/eq), methoxyl content (5.43±0.22 to 1.86±0.00%), and degree of esterification (38.4±0.34 to 5.56±0.22%). In contrast, the galacturonic acid content increased (80.23±3.95 to 190.18±7.47%). FTIR analysis confirmed that higher citric acid concentrations significantly influenced the structural and chemical characteristics of the pectin. Overall, extraction using citric acid at concentrations of 0.1–1 M produced pectin classified as low-methoxyl and low-ester pectin, with potential applications in calcium-induced gel systems, low-sugar food products, thickeners, and biodegradable edible films. Future studies should optimize extraction conditions, including pH, temperature, time, and solvent-to-solid ratio, to enhance pectin yield and quality. © 2026 by Authors.
Department of Chemical Engineering, Faculty of Industrial Technology, Institut Teknologi Sumatera, Lampung, Indonesia; Department of Food Technology, Faculty of Industrial Technology, Institut Teknologi Sumatera, Lampung, Indonesia