Effect Of Manual Depulping And Roasting On Functional, Rheological And Sensory Characteristics Of Cocoa Liquor

Abstract

Cocoa liquor serves as a fundamental intermediate in chocolate production, with its quality attributes largely determined by post-harvest processing parameters. This study investigated the effects of varying mechanical depulping levels (0 %, 50 % and 100 % pulp removal) and roasting conditions (110 min and 135 ◦ ◦ C for 60 min, 120 ◦ C for 30 C for 10 min) on the physical and sensory characteristics of cocoa liquor produced from Ghanaian cocoa beans (Theobroma cacao L.). A 3 × 3 full factorial design was implemented under a Completely Rando mised Design framework. Following standardised fermentation (6 days) and drying (55 ◦ C to 7–8 % moisture content), beans were roasted, milled and evaluated for textural properties (firmness: 175.93–584.80 g; consis tency: 963.66–1847.96 g⋅s; cohesiveness: 165.02–360.64 g) and viscosity index (728.5–1364.9 g⋅s) using back- extrusion analysis. Quantitative Descriptive Analysis by 10 trained panellists (2 males, 8 females; age range 25–45 years) assessed nine sensory attributes. Results demonstrated that depulping significantly reduced cohesiveness (F (1,23) =4.58, p = 0.043) and modified consistency (F(3,23) =5.87, p = 0.0066), with 100 % depulping decreasing cohesiveness by 54 % compared to undepulped controls. Complete depulping intensified bitterness (p < 0.05) and astringency, attributable to elevated polyphenol retention (Asiedu et al., 2025). Moderate roasting at 120 ◦ C for 30 min produced optimal nutty and cocoa notes, particularly in non-depulped samples which exhibited significantly higher cocoa liquor aroma and flavour intensities (p < 0.05). Strong correlations emerged between cohesiveness and viscosity index (r = 0.95, R 2 of 50 % depulping with moderate roasting (120 ◦ =0.91, p < 0.05). The combination C/30 min) yielded cocoa liquor with improved texture, stable rheology (consistency: 1245.32 g⋅s) and enhanced sensory quality, providing practical guidance for optimising cocoa processing operations.