Preparation and Characterization of Pectin-based Biopolymer from Combination of Coffee and Cocoa Husks as Agroindustrial Waste Utilization

Department of Agricultural and Biosystem Engineering, Faculty of Agricultural Technology, Universitas Gadjah Mada, 55281 Yogyakarta, Indonesia.

^* Corresponding author: prieskarindalestari@ugm.ac.id

Abstract

Coffee and cocoa are among the largest commodities in Indonesia. During the processing, high amounts of these husks are generated as agricultural waste that contains pectin, which applicable to be used for biopolymers. The research aimed to 1) extract pectin from coffee and cocoa husks and 2) synthesize and characterize pectin-based biopolymers from both husks. Pectin extraction was done based on alcoholic precipitation methods. About 6.82% and 4.91% of pectin were extracted per 100 g of dried coffee and cocoa husk powder, respectively. FTIR has confirmed the extracted pectin from both husks. This study applied two compositional variations: pectin coffee biopolymer (CB) with a 1:0 ratio of coffee pectin to cocoa pectin, and combined pectin biopolymer from coffee and cocoa (CCB) with a 1:1 ratio. Thickness, lightness, and tensile strength of biopolymer variation CB were obtained at 0.16 mm; 28.76; and 0.00012 MPa, respectively. The thickness, lightness, and tensile strength of biopolymer variation CCB were 0.24 mm; 37.41; and 0.00014 MPa. The soil burial degradation test over 3 days, CB and CCB biopolymers showed respective biodegradability of 99.58% and 99.63%. These findings confirm pectin from coffee and cocoa husks can create valuable biopolymers, with further development required to expand applications