Comparative analysis of physicochemical properties in selected cocoa bean varieties

Abstract

Cocoa (Theobroma cacao L.) remains a vital cash crop in Uganda, supporting over 80,000 smallholder farmers and generating US$68.7 million in exports by February 2025, yet faces challenges from genotypic variability in physicochemical properties that affect processing efficiency and product quality. This study aimed to determine the physicochemical attributes of nine selected Ugandan cocoa clones (KT/03/OLD/ series) to enhance quality assessment and utilization. Samples were collected, fermented, dried (sun and oven at 45°C), ground, and analyzed for physical (fibre content, bean length, weight) and chemical (protein, carbohydrates, phenolics, flavonoids) properties using standard spectrophotometric and Kjeldahl methods at Makerere University's School of Agricultural Sciences laboratory. One-way ANOVA revealed highly significant differences (p < 0.001) across traits, with fibre ranging 9.14 –19.14% (KT/03/OLD/387 highest), bean length 1.90 –2.33 cm, and weight 0.98 –1.31 g. Chemically, protein varied 12.47–16.99% (KT/03/OLD/001 and 454 highest), carbohydrates (490 nm absorbance) 0.670 –1.188 (KT/03/OLD/246 highest), phenolics (765 nm) 0.224 –0.360, and flavonoids (510 nm) 0.524 –2.268 (KT/03/OLD/246 dominant). Pearson correlations confirmed a strong positive link between bean length and weight (r = 0.888, p < 0.01), positive phenolics-flavonoids association (r = 0.683, p < 0.05), and negative protein-phenolics (r = -0.827, p < 0.01), partially supporting hypotheses on compositional differences and size-biochemical ties. These findings bridge data gaps, informing breeding for resilient hybrids and optimized post-harvest practices to boost Uganda's cocoa value chain, aligning with sustainable development goals for food security and economic empowerment